subject:(Phased arrays)

Texas A&M University

1. Jensen, Jeffrey. A Cognitive Phased Array Using Smart Phone Control.

Degree: MS, Electrical Engineering, 2012, Texas A&M University

URL: http://hdl.handle.net/1969.1/ETD-TAMU-2012-05-10856

► Cognitive radio networks require the use of computational resources to reconfigure transmit/receive parameters to improve communication quality of service or efficiency. Recent emergence of smart… (more)

▼ Cognitive radio networks require the use of computational resources to reconfigure transmit/receive parameters to improve communication quality of service or efficiency. Recent emergence of smart phones has made these resources more accessible and mobile, combining sensors, geolocation, memory and processing power into a single device. Thus, this work examines an integration of a smart phone into a complex radio network that controls the beam direction of a phased array using a conventional method, but utilizes the phone's internal sensors as an enhancement to generate beam direction information, Bluetooth channel to relay information to control circuitry, and Global Position System (GPS) to track an object in motion. The research and experiments clearly demonstrate smart phone's ability to utilize internal sensors to generate information used to control beam direction from a phased array. Computational algorithms in a network of microcontrollers map this information into a DC bias voltage which is applied to individual phase shifters connected to individual array elements. To test algorithms and control theory, a 4 by 4 microstrip patch array is designed and fabricated to operate at a frequency of 2.4 GHz. Simulations and tests of the array provide successful antenna design results with satisfactory design parameters. Smart phone control circuitry is designed and tested with the array. Anechoic test results yield successful beam steering capability scanning 90 degrees at 15 degree intervals with 98% accuracy in all cases. In addition, the system achieves successful beam steering operable over a bandwidth of 100 MHz around resonance. Furthermore, these results demonstarate the capability of the smart phone controlled system to be used in testing further array formations to achieve beam steering in 3-Dimensional space. It is further noted that the system extends capabilities of integrating other control methods which use the smart phone to process information. Advisors/Committee Members: Huff, Gregory H. (advisor), Chamberland, Jean-Francois (committee member), Pfister, Henry (committee member), Hogan, Harry (committee member).

Subjects/Keywords: Phased Arrays; Phased Array Control; Smartphone

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APA (6^th Edition):

Jensen, J. (2012). A Cognitive Phased Array Using Smart Phone Control. (Masters Thesis). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/ETD-TAMU-2012-05-10856

Chicago Manual of Style (16^th Edition):

Jensen, Jeffrey. “A Cognitive Phased Array Using Smart Phone Control.” 2012. Masters Thesis, Texas A&M University. Accessed April 18, 2021. http://hdl.handle.net/1969.1/ETD-TAMU-2012-05-10856.

MLA Handbook (7^th Edition):

Jensen, Jeffrey. “A Cognitive Phased Array Using Smart Phone Control.” 2012. Web. 18 Apr 2021.

Vancouver:

Jensen J. A Cognitive Phased Array Using Smart Phone Control. [Internet] [Masters thesis]. Texas A&M University; 2012. [cited 2021 Apr 18]. Available from: http://hdl.handle.net/1969.1/ETD-TAMU-2012-05-10856.

Council of Science Editors:

Jensen J. A Cognitive Phased Array Using Smart Phone Control. [Masters Thesis]. Texas A&M University; 2012. Available from: http://hdl.handle.net/1969.1/ETD-TAMU-2012-05-10856

Cranfield University

2. Fourtinon, L. 3D conformal antennas for radar applications.

Degree: PhD, 2018, Cranfield University

URL: http://dspace.lib.cranfield.ac.uk/handle/1826/13359 ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.753704

► Embedded below the radome of a missile, existing RF-seekers use a mechanical rotating antenna to steer the radiating beam in the direction of a target.… (more)

Subjects/Keywords: 621.384; Conformal; Phased arrays; Ellipticity

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APA (6^th Edition):

Fourtinon, L. (2018). 3D conformal antennas for radar applications. (Doctoral Dissertation). Cranfield University. Retrieved from http://dspace.lib.cranfield.ac.uk/handle/1826/13359 ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.753704

Chicago Manual of Style (16^th Edition):

Fourtinon, L. “3D conformal antennas for radar applications.” 2018. Doctoral Dissertation, Cranfield University. Accessed April 18, 2021. http://dspace.lib.cranfield.ac.uk/handle/1826/13359 ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.753704.

MLA Handbook (7^th Edition):

Fourtinon, L. “3D conformal antennas for radar applications.” 2018. Web. 18 Apr 2021.

Vancouver:

Fourtinon L. 3D conformal antennas for radar applications. [Internet] [Doctoral dissertation]. Cranfield University; 2018. [cited 2021 Apr 18]. Available from: http://dspace.lib.cranfield.ac.uk/handle/1826/13359 ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.753704.

Council of Science Editors:

Fourtinon L. 3D conformal antennas for radar applications. [Doctoral Dissertation]. Cranfield University; 2018. Available from: http://dspace.lib.cranfield.ac.uk/handle/1826/13359 ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.753704

University of Illinois – Urbana-Champaign

3. [No author]. The optimal starting point for antenna array design.

Degree: M.S. (master's), Electrical & Computer Engr, 2016, University of Illinois – Urbana-Champaign

URL: http://hdl.handle.net/2142/97809

► Many of today's wireless systems depend on the increased gain and pattern flexibility offered by phased arrays. While numerous "novel" one-off solutions as well as… (more)

Subjects/Keywords: Phased arrays; Antenna synthesis

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APA (6^th Edition):

author], [. (2016). The optimal starting point for antenna array design. (Masters Thesis). University of Illinois – Urbana-Champaign. Retrieved from http://hdl.handle.net/2142/97809

Chicago Manual of Style (16^th Edition):

author], [No. “The optimal starting point for antenna array design.” 2016. Masters Thesis, University of Illinois – Urbana-Champaign. Accessed April 18, 2021. http://hdl.handle.net/2142/97809.

MLA Handbook (7^th Edition):

author], [No. “The optimal starting point for antenna array design.” 2016. Web. 18 Apr 2021.

Vancouver:

author] [. The optimal starting point for antenna array design. [Internet] [Masters thesis]. University of Illinois – Urbana-Champaign; 2016. [cited 2021 Apr 18]. Available from: http://hdl.handle.net/2142/97809.

Council of Science Editors:

author] [. The optimal starting point for antenna array design. [Masters Thesis]. University of Illinois – Urbana-Champaign; 2016. Available from: http://hdl.handle.net/2142/97809

University of Waterloo

4. Abdellatif, Ahmed Shehata Mohamed. High Performance Integrated Beam-Steering Techniques for Millimeter-Wave Systems.

Degree: 2015, University of Waterloo

URL: http://hdl.handle.net/10012/9527

► Recently, the research and development of low cost and highly efficient millimeter-wave (mmWave) systems with beam-steering capabilities have significantly advanced to address the ever-increasing demand… (more)

▼ Recently, the research and development of low cost and highly efficient millimeter-wave (mmWave) systems with beam-steering capabilities have significantly advanced to address the ever-increasing demand for future wireless ultra-broadband applications. These applications include, but are not limited to, automotive anti-collision surveillance radar, smart navigation systems, improved wireless tracking, satellite communication, imaging, 5G wireless communication, and 60GHz multi-gigabit wireless personal and local area network (WPAN/WLAN). In general, beam-steering capability significantly relaxes the overall system power budget and minimizes the interference. In communication applications, it enhances the link robustness through multi-path mitigation and increases the channel and the aggregated channel throughput by exploiting the spatial dimension. In imaging/radar systems, beam-steering is essential for achieving the required resolution (angle-of-arrival). In this work, I have proven many beam-steering advantages in this work through the development of a ray-tracing based wireless channel model, which has been used to extract the antenna system requirements and to quantitatively illustrate the usefulness of the presented beam-steerable systems. Despite the advantages it provides, the realization of this electronic beam-steerable mmWave antenna system is quite challenging. In general, the mmWave components' design, integration, fabrication and testing processes are far more complex than their lower frequency counterparts. This can be attributed to the significant losses and parasitics experienced at mmWave frequencies, as well as the lack of reliable design models. Systems with fully integrated (on-chip) antennas and passives have been widely studied and presented at mmWave range; however, the performance (low antenna gain, high phase noise, etc…), the cost (die size is huge), and thermal problems are still major issues for these systems. Hybrid integration tackles these problems by combining a compact and low power consumption die (or multiple dies) with high performance off-chip passives (antenna, feed network, passive phase shifters, resonators, etc…); however, this integration is costly. In addition, there is a challenge associated with the implementation of high performance components at mmWave range. This is mainly due to the use of advanced/non-standard types of fabrication technologies and complex integration/packaging techniques. Investigation, optimization, development of a highly efficient and yet very low cost mmWave beam-steering solution calls for a multi-disciplinary approach which involves EM theory, optimization techniques, microwave circuits, wireless communications, Silicon micro-fabrication, layout design, parasitics modeling/extraction and MEMS technology. The proposed study introduces a high performance beam-steering mmWave antenna system along with its integration with the active components with special consideration to the fabrication cost. The new high resistivity Silicon (HRS)…

Subjects/Keywords: beam-steering; millimeter-wave; phased arrays; antennas

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APA (6^th Edition):

Abdellatif, A. S. M. (2015). High Performance Integrated Beam-Steering Techniques for Millimeter-Wave Systems. (Thesis). University of Waterloo. Retrieved from http://hdl.handle.net/10012/9527

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Abdellatif, Ahmed Shehata Mohamed. “High Performance Integrated Beam-Steering Techniques for Millimeter-Wave Systems.” 2015. Thesis, University of Waterloo. Accessed April 18, 2021. http://hdl.handle.net/10012/9527.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Abdellatif, Ahmed Shehata Mohamed. “High Performance Integrated Beam-Steering Techniques for Millimeter-Wave Systems.” 2015. Web. 18 Apr 2021.

Vancouver:

Abdellatif ASM. High Performance Integrated Beam-Steering Techniques for Millimeter-Wave Systems. [Internet] [Thesis]. University of Waterloo; 2015. [cited 2021 Apr 18]. Available from: http://hdl.handle.net/10012/9527.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Abdellatif ASM. High Performance Integrated Beam-Steering Techniques for Millimeter-Wave Systems. [Thesis]. University of Waterloo; 2015. Available from: http://hdl.handle.net/10012/9527

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

5. Shearwood, Jake. Development of a power based angle of arrival system for tracking of bee utlilising a miniature vibration energy harvester for a battery-less transmitter.

Degree: PhD, 2020, Bangor University

URL: https://research.bangor.ac.uk/portal/en/theses/development-of-a-power-based-angle-of-arrival-system-for-tracking-of-bee-utlilising-a-miniature-vibration-energy-harvester-for-a-batteryless-transmitter(1dd702f1-6b95-4572-aa4a-377c2d4459e3).html ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.821250

► The thesis presents the adaption of radio telemetry technology to allow for the tracking of the world’s most economically beneficial insect, the honeybee. Currently no… (more)

▼ The thesis presents the adaption of radio telemetry technology to allow for the tracking of the world’s most economically beneficial insect, the honeybee. Currently no technology is available to efficiently enable the long-term evaluation of navigation loss of bees exposed to potentially harmful pesticides such as neonicotinoids. The research aims at developing a self-sustained radio tracking device which can be attached to insects as small as the honeybee. The research presented within the thesis acts as a proof of principle for long range autonomous tracking of bees using a modified radio telemetry. To allow for compatibility of radio telemetry tags with smaller tags were designed and fabricated which implements a micro-generator that harvests electrical energy from the bee’s body vibrations which powers radio-wave transmission from a miniaturized antenna attached to the bees’ thorax. The use of lead zirconate titanate (PZT) allowed for sufficient power generation to replace the battery, whilst an increased operation frequency in comparison to current state of the art allowed for sufficient antenna size reduction. Both factors contributed to a significant weight reduction allowing for compatibility with honeybees. The successful transmission of the selfpowered radio telemetry tags is shown whilst outlining the effects of the battery replacement and increased frequency on the link budget of the system. A review of localisation systems for radio telemetry systems was performed in which alternative methods were investigated to allow for autonomous localisation of the radio telemetry tag with a single receiver. A compact phased array antenna affords angle of arrival (AOA) estimation and bee localisation through a received signal strength indicator approach (RSSI). The phased array antenna is capable of scanning +/-50° in azimuth and elevation. Additionally, a reflection type phase shifter capable of a 360° phase shift was designed and fabricated. Initial tests of the system were conducted in controlled environments and highlighted the system’s ability to detect and determine the AoA of a tagged bee within a 20m range. Further tests demonstrated the systems unobtrusive nature when monitoring the foraging times of tagged bees whilst recording their initial flight trajectories. Commercial applications of the system are shown in which the system is mounted within a polytunnel to monitor plant visitations and pollinator services on strawberry plants. To overcome the 20m detection range and achieve long range tracking of tagged bees the receiver unit was integrated to a drone in which the AOA estimate is autonomously fed into the control system of a drone, allowing for continuous position updates. The drone interprets the estimate in which a bearing is calculated before the drone autonomously moves towards the position of the AoA estimate. The experimental results show proof of concept towards autonomous tracking of tagged bees.

Subjects/Keywords: Energy harvesting; Localisation; Phased arrays; RSSI; Telemetry

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APA (6^th Edition):

Shearwood, J. (2020). Development of a power based angle of arrival system for tracking of bee utlilising a miniature vibration energy harvester for a battery-less transmitter. (Doctoral Dissertation). Bangor University. Retrieved from https://research.bangor.ac.uk/portal/en/theses/development-of-a-power-based-angle-of-arrival-system-for-tracking-of-bee-utlilising-a-miniature-vibration-energy-harvester-for-a-batteryless-transmitter(1dd702f1-6b95-4572-aa4a-377c2d4459e3).html ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.821250

Chicago Manual of Style (16^th Edition):

Shearwood, Jake. “Development of a power based angle of arrival system for tracking of bee utlilising a miniature vibration energy harvester for a battery-less transmitter.” 2020. Doctoral Dissertation, Bangor University. Accessed April 18, 2021. https://research.bangor.ac.uk/portal/en/theses/development-of-a-power-based-angle-of-arrival-system-for-tracking-of-bee-utlilising-a-miniature-vibration-energy-harvester-for-a-batteryless-transmitter(1dd702f1-6b95-4572-aa4a-377c2d4459e3).html ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.821250.

MLA Handbook (7^th Edition):

Shearwood, Jake. “Development of a power based angle of arrival system for tracking of bee utlilising a miniature vibration energy harvester for a battery-less transmitter.” 2020. Web. 18 Apr 2021.

Vancouver:

Shearwood J. Development of a power based angle of arrival system for tracking of bee utlilising a miniature vibration energy harvester for a battery-less transmitter. [Internet] [Doctoral dissertation]. Bangor University; 2020. [cited 2021 Apr 18]. Available from: https://research.bangor.ac.uk/portal/en/theses/development-of-a-power-based-angle-of-arrival-system-for-tracking-of-bee-utlilising-a-miniature-vibration-energy-harvester-for-a-batteryless-transmitter(1dd702f1-6b95-4572-aa4a-377c2d4459e3).html ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.821250.

Council of Science Editors:

Shearwood J. Development of a power based angle of arrival system for tracking of bee utlilising a miniature vibration energy harvester for a battery-less transmitter. [Doctoral Dissertation]. Bangor University; 2020. Available from: https://research.bangor.ac.uk/portal/en/theses/development-of-a-power-based-angle-of-arrival-system-for-tracking-of-bee-utlilising-a-miniature-vibration-energy-harvester-for-a-batteryless-transmitter(1dd702f1-6b95-4572-aa4a-377c2d4459e3).html ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.821250

University of Cambridge

6. ndifon, ajeck. DISTRIBUTED PHASED ARRAY ANTENNAS IN WIDE AREA RFID.

Degree: PhD, 2020, University of Cambridge

URL: https://www.repository.cam.ac.uk/handle/1810/301495

► Ultra High Frequency (UHF) Radio Frequency Identification (RFID) has gained importance over the past two decades in many applications such as stock management, asset tracking… (more)

▼ Ultra High Frequency (UHF) Radio Frequency Identification (RFID) has gained importance over the past two decades in many applications such as stock management, asset tracking and access control. For wide area applications, Distributed Antenna Systems (DAS) have been used to obtain good coverage with few antennas by making use of multiple spatially distributed antennas and phase dithering. This implements a far-field beamforming that maximises the instantaneous power at a tag. Separately, phased array antennas have also been used to increase the read range by increasing the effective field of view of an antenna and overcoming multipath fading through beam steering. This dissertation explores a combination of both approaches to improve RFID read ranges in wide interrogation zones. Distributed antenna arrays are explored in the context of delivering high tag detection probabilities in a multi-cell RFID system, while maximising inter-antenna separations. A Distributed Antenna Array System (DAAS) is designed and shown to be capable of providing comparable performance to a fixed DAS system with fewer antennas. The properties of the system are further studied and its upper performance limit is explored by modelling a hypothetical perfectly steerable antenna array. The concept of using perfectly steerable arrays is further explored to propose a cell-less RFID system, in which cell allocation in wide area RFID is replaced with a tag location-based interrogation requiring the global reader antenna population to be used for interrogation of all tags, leading to significant potential increases in inter-antenna separation, and consequently good coverage with fewer antennas. It is also argued that this system leads to the avoidance of complex reader anti-collision policies, since only a single central reader is now required. Finally, the design of a wide-scan-angle antenna array is presented as a compromise solution for perfectly steerable antennas, whist still keeping the desired property of being flat panel. A 3D RFID multi-antenna model is presented and used for simulating and analysing the various described systems and for system planning.

Subjects/Keywords: RFID; Radio Frequency Identification; RF propagation; phased arrays; antenna arrays

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APA (6^th Edition):

ndifon, a. (2020). DISTRIBUTED PHASED ARRAY ANTENNAS IN WIDE AREA RFID. (Doctoral Dissertation). University of Cambridge. Retrieved from https://www.repository.cam.ac.uk/handle/1810/301495

Chicago Manual of Style (16^th Edition):

ndifon, ajeck. “DISTRIBUTED PHASED ARRAY ANTENNAS IN WIDE AREA RFID.” 2020. Doctoral Dissertation, University of Cambridge. Accessed April 18, 2021. https://www.repository.cam.ac.uk/handle/1810/301495.

MLA Handbook (7^th Edition):

ndifon, ajeck. “DISTRIBUTED PHASED ARRAY ANTENNAS IN WIDE AREA RFID.” 2020. Web. 18 Apr 2021.

Vancouver:

ndifon a. DISTRIBUTED PHASED ARRAY ANTENNAS IN WIDE AREA RFID. [Internet] [Doctoral dissertation]. University of Cambridge; 2020. [cited 2021 Apr 18]. Available from: https://www.repository.cam.ac.uk/handle/1810/301495.

Council of Science Editors:

ndifon a. DISTRIBUTED PHASED ARRAY ANTENNAS IN WIDE AREA RFID. [Doctoral Dissertation]. University of Cambridge; 2020. Available from: https://www.repository.cam.ac.uk/handle/1810/301495

Texas A&M University

7. Jensen, Jeffrey S. A Framework for Computer Vision Assisted Beamforming in Aperiodic Phased Arrays.

Degree: PhD, Electrical Engineering, 2015, Texas A&M University

URL: http://hdl.handle.net/1969.1/156463

► Mobile networks, unmanned air vehicles (UAVs), and other dynamic wireless systems are prevalent in several widespread military and commercial applications due dynamic ability to adapt… (more)

▼ Mobile networks, unmanned air vehicles (UAVs), and other dynamic wireless systems are prevalent in several widespread military and commercial applications due dynamic ability to adapt to an environment and commonly implemented autonomous control. Their mobility and dynamic reconfiguration create randomly dispersed networks that inherently give rise to significant electromagnetic challenges in collaborative applications such as beamforming. Conventional radio and communication systems overcome these challenges through designs that are highly structured with respect to frequency and are static in nature. Two inherent problems prevent collaborative electromagnetic capabilities in these disparate random geometrical systems: cognizance of node positioning and local synchronization of oscillators, phase, and information. This work proposes the combined use of image processing techniques and infrared depth-of-field sensing to detect and track node position in a phased array control framework for morphing clusters of randomly distributed antennas. This framework is presented and designed to uniquely identify array elements (or platforms) and track the motion-dynamic spatial distribution to provide feedback and control information for phase shifting and beamforming. A primary metric of this work is to examine the core performance of the phased array control system with respect to beamforming accuracy. This begins with the use of image recognition algorithms in a reconnaissance phase to establish element identities and determine their locations in the field of view. This process informs the depth-of-field sensor to prompt evaluation of the spatial distribution of elements and enable element location tracking through time. This information is communicated to a distributed array controller that identifies the characteristic function of the array (triangular, spheroidal, etc.), and calculates phases for the elements to achieve the desired beam steering operation. The framework also includes a mobile device (smartphone, tablet, etc.) as a user interface which can be used to control the phased array and link geolocation information for autonomous tracking modes. A framework operating at 2.48 GHz has been developed using low-cost off-the-shelf components, as well as custom-designed element platforms so the performance of the system can be observed experimentally. Results for element identification and spatial distribution are included to benchmark the accuracy of the aforementioned system. Next, a series of experiments demonstrates the operation of the proposed system through radiation patterns that incorporate beam steering and other complex control mechanisms. Analysis of the patterns shows from various geometrical topologies is presented to demonstrate the capability of the system to analyze morphing swarms and clusters. Finally, a conclusion presents findings from some noticeable differences in simulated and measured results. Advisors/Committee Members: Huff, Gregory H (advisor), Chamberland, Jean-Francois (committee member), Nevels, Robert D (committee member), Hogan, Harry A (committee member).

Subjects/Keywords: Mobile Networks; Ad hoc beamforming; Swarm Intelligence; Random Arrays; Phased Arrays; Electromagnetics

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APA (6^th Edition):

Jensen, J. S. (2015). A Framework for Computer Vision Assisted Beamforming in Aperiodic Phased Arrays. (Doctoral Dissertation). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/156463

Chicago Manual of Style (16^th Edition):

Jensen, Jeffrey S. “A Framework for Computer Vision Assisted Beamforming in Aperiodic Phased Arrays.” 2015. Doctoral Dissertation, Texas A&M University. Accessed April 18, 2021. http://hdl.handle.net/1969.1/156463.

MLA Handbook (7^th Edition):

Jensen, Jeffrey S. “A Framework for Computer Vision Assisted Beamforming in Aperiodic Phased Arrays.” 2015. Web. 18 Apr 2021.

Vancouver:

Jensen JS. A Framework for Computer Vision Assisted Beamforming in Aperiodic Phased Arrays. [Internet] [Doctoral dissertation]. Texas A&M University; 2015. [cited 2021 Apr 18]. Available from: http://hdl.handle.net/1969.1/156463.

Council of Science Editors:

Jensen JS. A Framework for Computer Vision Assisted Beamforming in Aperiodic Phased Arrays. [Doctoral Dissertation]. Texas A&M University; 2015. Available from: http://hdl.handle.net/1969.1/156463

Texas A&M University

8. Kim, Sang Gyu. Wideband two-dimensional and multiple beam phased arrays and microwave applications using piezoelectric transducers.

Degree: PhD, Engineering, 2005, Texas A&M University

URL: http://hdl.handle.net/1969.1/2335

► Modern satellite, wireless communication, and radar systems often demand wideband performance for multi-channel operation and the ability to steer multiple beams for multiple moving targets.… (more)

▼ Modern satellite, wireless communication, and radar systems often demand wideband performance for multi-channel operation and the ability to steer multiple beams for multiple moving targets. This dissertation covers a variety of topics to design low-cost and wideband antenna systems. The main areas of study are microwave devices controlled piezoelectric transducers (PETs) and wideband baluns and balanced microwave circuits using parallel-strip lines. Some focus has also been given to the design of Rotman lens for multiple beam generation and Vivaldi antenna arrays for wideband two-dimensional scanning. The dielectric perturbation technique controlled by PET is introduced to design a wideband phase shifter and a QPSK modulator, and to tune the resonant frequency of a slot dipole. The designed PET-controlled phase shifters are used for beam steering in a dual beam phased array using a bidirectional feeding scheme and a five-beam phased array using a microstrip Rotman lens. Vivaldi-type antennas are commonly used to achieve wideband performance. Very wideband performance can be achieved using an antipodal tapered slot antenna because of its inherent simple wideband transition from microstrip line to parallel-strip line. An antipodal tapered slot antenna and a phased array are designed to span 10 to 35 GHz. In addition, a 4??4 two-dimensional antenna array is designed using wideband antipodal tapered slot antennas, and two sets of PET-controlled phase shifters for E- and H-plane scanning are fabricated to steer the beam. As a microwave system using wideband antenna array, a new low-cost and wideband phased array radar is developed using a modulated pulse over 8 to 20 GHz band. The double-sided parallel-strip line as a balanced line is presented. The parallelstrip line offers much flexibility for microwave circuit designs. This transmission line makes it possible to realize a low impedance line and allows the design of a compact wideband balun and junction. Wideband transitions (or baluns) from parallel-strip line to microstrip line, a typical unbalanced transmission line, are realized to cover several octave bandwidth. Balanced microwave filters and a hybrid coupler are developed using the parallel-strip line. Advisors/Committee Members: Chang, Kai (advisor), Naugle, Donald G. (committee member), Nevels, Robert D. (committee member), Su, Chin B. (committee member).

Subjects/Keywords: phased arrays; piezoelectric transducers

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APA (6^th Edition):

Kim, S. G. (2005). Wideband two-dimensional and multiple beam phased arrays and microwave applications using piezoelectric transducers. (Doctoral Dissertation). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/2335

Chicago Manual of Style (16^th Edition):

Kim, Sang Gyu. “Wideband two-dimensional and multiple beam phased arrays and microwave applications using piezoelectric transducers.” 2005. Doctoral Dissertation, Texas A&M University. Accessed April 18, 2021. http://hdl.handle.net/1969.1/2335.

MLA Handbook (7^th Edition):

Kim, Sang Gyu. “Wideband two-dimensional and multiple beam phased arrays and microwave applications using piezoelectric transducers.” 2005. Web. 18 Apr 2021.

Vancouver:

Kim SG. Wideband two-dimensional and multiple beam phased arrays and microwave applications using piezoelectric transducers. [Internet] [Doctoral dissertation]. Texas A&M University; 2005. [cited 2021 Apr 18]. Available from: http://hdl.handle.net/1969.1/2335.

Council of Science Editors:

Kim SG. Wideband two-dimensional and multiple beam phased arrays and microwave applications using piezoelectric transducers. [Doctoral Dissertation]. Texas A&M University; 2005. Available from: http://hdl.handle.net/1969.1/2335

Penn State University

9. Kannajosyula, Haraprasad. Novel array based methods for ultrasonic guided wave non destructive evaluation .

Degree: 2012, Penn State University

URL: https://submit-etda.libraries.psu.edu/catalog/15547

► In this thesis two related aspects are studied in ultrasonic non-destructive evaluation(NDE) and structural health monitoring(SHM), that can be broadly classified under guided wave mode… (more)

▼ In this thesis two related aspects are studied in ultrasonic non-destructive evaluation(NDE) and structural health monitoring(SHM), that can be broadly classified under guided wave mode selection . The two aspects of guided wave mode selection under consideration are: a) Identification of guided wave mode(s) suitable for a particular application and b) Methods for generating the guided wave mode that is desired, identified, or considered as suitable for a particular application, in preference to all possible modes that would otherwise be generated using an arbitrary excitation method. For the first aspect, formalism and algorithms for a guided wave mode identification are presented. The proposed algorithms are independent of computation of wavestructure or the cross-sectional distribution of field quantities. Numerical examples are presented detail- ing the implementation of the algorithm.The mode identification algorithm is applied for non-destructive evaluation of interface-like waves in a composite panel. Numerical and ex- perimental studies are performed to explore the performance of interface waves for debonds and impact induced delamination defects. Methods of preferential guided wave mode generation: and their steering are studied. Linear 1D phase array transducers are studied in detail to highlight their shortcomings when applied to preferential generation and steering of guided wave modes and also to introduce new methods of array excitation in a simple fashion. The subject of multiple mode generation by 1D linear arrays is highlighted. Nonlinear time delay excitation of phased array transducers is introduced. Amplitude control of array transducers for preferential mode generation and steering is introduced. Performance of Linear 1D arrays with linear time delay, nonlinear time delay and amplitude control are compared both numerically and iii experimentally. A voltage divider network is proposed as a one-to-many channel converter for producing variable amplitude output and is used for amplitude control of a transducer array. Detailed mathematical analysis of annular phased array transducers is presented. Exact formulae for computing phased delays are derived. Closed form expressions for computing the wavenumber spectrum components responsible for incoming and outgoing waves are derived. Amplitude controlled semicircular annular arrays are proposed as an alternate solution for avoiding interference between incoming and outgoing wave components found in fully circular annular phased array transducers. Experiments are performed to validate the theoretical predictions. A miniature semicircular annular array was fabricated for this while taking care to minimize cross talk between array elements. 2D phased array transducers are studied with the aim of implementation in anisotropic composite panels. It is proposed that for guided wave modes in anisotropic composites with skew (or tendency of wave packets to naturally drift away from intended direction), transducers capable of generating large beam width be used. 2D… Advisors/Committee Members: Clifford Jesse Lissenden Iii, Dissertation Advisor/Co-Advisor, Joseph Lawrence Rose, Dissertation Advisor/Co-Advisor, Clifford Jesse Lissenden Iii, Committee Chair/Co-Chair, Joseph Lawrence Rose, Committee Chair/Co-Chair, Bernhard R Tittmann, Committee Member, Edward C Smith, Committee Member.

Subjects/Keywords: Amplitude Control; Phased Arrays; Ultrasonic Guided Waves; Non Destructive Evaluation

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APA (6^th Edition):

Kannajosyula, H. (2012). Novel array based methods for ultrasonic guided wave non destructive evaluation . (Thesis). Penn State University. Retrieved from https://submit-etda.libraries.psu.edu/catalog/15547

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Kannajosyula, Haraprasad. “Novel array based methods for ultrasonic guided wave non destructive evaluation .” 2012. Thesis, Penn State University. Accessed April 18, 2021. https://submit-etda.libraries.psu.edu/catalog/15547.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Kannajosyula, Haraprasad. “Novel array based methods for ultrasonic guided wave non destructive evaluation .” 2012. Web. 18 Apr 2021.

Vancouver:

Kannajosyula H. Novel array based methods for ultrasonic guided wave non destructive evaluation . [Internet] [Thesis]. Penn State University; 2012. [cited 2021 Apr 18]. Available from: https://submit-etda.libraries.psu.edu/catalog/15547.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Kannajosyula H. Novel array based methods for ultrasonic guided wave non destructive evaluation . [Thesis]. Penn State University; 2012. Available from: https://submit-etda.libraries.psu.edu/catalog/15547

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

University of Waterloo

10. Faraji-Dana, MohammadSadegh. Miniaturized Phase-Shifters for Ka-Band Phased Array Antennas.

Degree: 2014, University of Waterloo

URL: http://hdl.handle.net/10012/8723

► Realizing robust and stable two-way links between the mobile users and the satellite is an extremely challenging RF/Microwave engineering problem. Low cost and low profile… (more)

▼ Realizing robust and stable two-way links between the mobile users and the satellite is an extremely challenging RF/Microwave engineering problem. Low cost and low profile phased array is considered as the best solution for this problem. High performance low cost and miniaturized variable phase shifter is a key enabling technology for such complex smart phased array antenna system. This thesis aims at the investigation of the existing solutions to realize miniaturized, low-cost and at the same time integrable phase shifters for commercial phased array antenna systems. Among few existing approaches, analog phase shifting devices based on voltage-tunable materials offers a promising solution. Liquid Crystal (LC) and Barium Strontium Titanate (BST) are the two voltage tunable materials, which, beside their own primary applications, have found their way into Microwave and mm-Wave tunable device technologies. In this study the utilization of LC and BST in analog phase shifters has been rigorously investigated, the advantages and drawbacks of each when applied in different realizations have been discussed and further development and improvements in designs have been suggested. To achieve more compact designs for Ka-band phase shifters, a comprehensive design methodology for tunable filter-type phase shifter is proposed in this dissertation. The most commonly used phase shifting architectures for the phased array antennas are RF, LO, IF and base-band phase shifting. It should be mentioned that LO, IF and base-band phase shifting are not suitable for phased arrays with large number of elements due to the formidable cost and complexity, particularly for Tx phased array systems which require one phase shifter per antenna element to meet the radiation mask. Therefore, this thesis is concentrated on RF (Microwave/mm-Wave) phase shifting, which is the most common for large phased array antenna systems. Since one of the most important requirement in the design of Ka-Band phase shifters for phased array systems is the high level of miniaturization, dictated by antenna element spacing constraint, the thesis also addresses the highly compact structure of such phase shifters. In particular, a novel phase shifting concept based on very high dielectric constant materials has been explored. It is shown that by using this new concept, a highly miniaturized variable phase shifter with more than 360 degrees phase tuning range is attainable.

Subjects/Keywords: Antennas & Propagation; Phase Shifters; Tunable Materials; Beam Scanning; Phased Arrays

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APA (6^th Edition):

Faraji-Dana, M. (2014). Miniaturized Phase-Shifters for Ka-Band Phased Array Antennas. (Thesis). University of Waterloo. Retrieved from http://hdl.handle.net/10012/8723

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Faraji-Dana, MohammadSadegh. “Miniaturized Phase-Shifters for Ka-Band Phased Array Antennas.” 2014. Thesis, University of Waterloo. Accessed April 18, 2021. http://hdl.handle.net/10012/8723.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Faraji-Dana, MohammadSadegh. “Miniaturized Phase-Shifters for Ka-Band Phased Array Antennas.” 2014. Web. 18 Apr 2021.

Vancouver:

Faraji-Dana M. Miniaturized Phase-Shifters for Ka-Band Phased Array Antennas. [Internet] [Thesis]. University of Waterloo; 2014. [cited 2021 Apr 18]. Available from: http://hdl.handle.net/10012/8723.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Faraji-Dana M. Miniaturized Phase-Shifters for Ka-Band Phased Array Antennas. [Thesis]. University of Waterloo; 2014. Available from: http://hdl.handle.net/10012/8723

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Texas Tech University

11. Boothby, Alexander. Investigation of phased array antenna systems for non-contact vital signs sensing.

Degree: MSin Electrical Engineering, Electrical Engineering, 2012, Texas Tech University

URL: http://hdl.handle.net/2346/73884

► The continuous and accurate monitoring of human vital signs is an extremely important part of the healthcare industry, as it is the basic means by… (more)

▼ The continuous and accurate monitoring of human vital signs is an extremely important part of the healthcare industry, as it is the basic means by which healthcare professionals monitor the instantaneous status of their patients. The ability to capture, record, and analyze vital signs information quickly can make a life-and-death difference in the ability for doctors and other healthcare professionals to make quick and informed decisions about patients’ conditions for treatments. Additionally, it has become increasingly desirable to use less invasive means by which to measure the vital signs data. This has led to much increased research spending in non-contact technologies which can monitor and transmit vital signs information quickly to the appropriate healthcare professionals. Additionally, since innovations in biomedical applications have been one of the biggest areas of research and development spending in the world, we will explore the benefits of using specialized antennas for increased performance and practicality of the non-contact vital signs (NCVS) biosensor that we have built in Professor Donald Lie’s RF/Analog SoC Labs. The purpose of this thesis is to explore the uses of high directivity antennas and electronically steerable phased array antenna systems to improve the performance and functionality of modern non-contact vital signs measurement systems. The primary focus of the applications of these specialized antennas in this work will be with the Doppler-based NCVS monitoring biosensor systems. It has been observed that that the accuracy of the NCVS sensor systems described in this and previous works can be diminished by reflections from background clutter in the measurement environment. One specific approach used to try and alleviate this issue is to employ the use of more directive antennas and phased arrays to steer the radiation beam towards a subject if they are not able to be properly illuminated by a typical commercial-off-the-shelf (COTS) antenna. The process and issues involved in designing customizable helical antennas that can be used in phased arrays or individually within the NCVS biosensor system will be described. In this thesis, the performance and accuracy of the NCVS biosensor is determined by the statistical analysis of a vast amount of data it collected and compared with the heart rate data measured from a physical and independent finger pulse sensor as the reference. We will explore how the different antenna and antenna systems affect the performance of the NCVS biosensor in this work. We believe this work is the 1st systematic study on using phased array systems for NCVS sensing performed in a clutter-free anechoic chamber, and it has shed some new and exciting lights on improving the existing NCVS sensor systems as brand new data has been collected and understood, which is especially important for enabling reliable, continuous and ubiquitous heart rate monitoring in the future. Advisors/Committee Members: Gale, Richard (committee member), Lie, Donald (Committee Chair).

Subjects/Keywords: Non-Contact Vital Signs Detection; Radar; Antennas; Phased Arrays; Biomedical Sensors

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APA (6^th Edition):

Boothby, A. (2012). Investigation of phased array antenna systems for non-contact vital signs sensing. (Masters Thesis). Texas Tech University. Retrieved from http://hdl.handle.net/2346/73884

Chicago Manual of Style (16^th Edition):

Boothby, Alexander. “Investigation of phased array antenna systems for non-contact vital signs sensing.” 2012. Masters Thesis, Texas Tech University. Accessed April 18, 2021. http://hdl.handle.net/2346/73884.

MLA Handbook (7^th Edition):

Boothby, Alexander. “Investigation of phased array antenna systems for non-contact vital signs sensing.” 2012. Web. 18 Apr 2021.

Vancouver:

Boothby A. Investigation of phased array antenna systems for non-contact vital signs sensing. [Internet] [Masters thesis]. Texas Tech University; 2012. [cited 2021 Apr 18]. Available from: http://hdl.handle.net/2346/73884.

Council of Science Editors:

Boothby A. Investigation of phased array antenna systems for non-contact vital signs sensing. [Masters Thesis]. Texas Tech University; 2012. Available from: http://hdl.handle.net/2346/73884

University of California – San Diego

12. Rupakula, Bhaskara Rao. Millimeter-wave Phased-arrays for Communication and their System-Level Impairments and Advantages.

Degree: Electrical and Computer Engineering, 2019, University of California – San Diego

URL: http://www.escholarship.org/uc/item/6093h7s0

► This dissertation presents millimeter-wave transmit/receive phased-arrays at 60 GHz, which are used to demonstrate long-range and high data-rate communication links. A 32-element one-dimensional (1-D) phased-array… (more)

▼ This dissertation presents millimeter-wave transmit/receive phased-arrays at 60 GHz, which are used to demonstrate long-range and high data-rate communication links. A 32-element one-dimensional (1-D) phased-array is built with 2 × 2 beamformer chips flipped on a low-cost printed circuit board. Series-fed microstrip antennas are used, which limits the bandwidth to around 2 GHz at 64 GHz center frequency. The phased-array scans only in the azimuth plane with a 3^o beamwidth and has a wide beam of 12^o in elevation. The phased-array's high effective isotropic radiated power (EIRP) of around 42 dBm and low noise figure of 6.5 dB enable long-range communication at 500 Mbps over 800 m.A two-dimensional (2-D) scanning phased-array is also built using the same beamformer chips on a more complex multilayer board. The 2-D phased-array has an EIRP of 45 dBm in saturation and scans up to +/- 15^o in the elevation plane and +/-50^o in the azimuth. Stacked microstrip antennas are used, enabling a wide bandwidth of ∼8 GHz for the phased-array. Data-rates of up to 30 Gbps are achieved with 64-QAM modulation using the full bandwidth of the phased-array.An analysis of intermodulation effects in receive-mode phased-arrays is presented and verified through experimental results from a Ka-band 5G phased-array. The intermodulation products are shown to peak at scan angles which do not correspond to the interferer directions.Experimental evidence is presented to show that the adjacent channel power ratio (ACPR) of transmit phased-arrays improves with larger number of elements at a given backoff from the compression point. This implies better transmit efficiency in larger phased-arrays. Finally, techniques are presented for reducing the number of phase-shifters in a 2-D phased-array while maintaining a limited scan range in the vertical and horizontal planes. It is shown that the number of phase-shifters can be reduced by 75%, while maintaining a scan range of +/-15^o in the elevation and +/-40^o in the azimuth.

Subjects/Keywords: Electrical engineering; Antennas; Beamforming; Millimeter-waves; Nonlinear circuits; Phased-arrays

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APA (6^th Edition):

Rupakula, B. R. (2019). Millimeter-wave Phased-arrays for Communication and their System-Level Impairments and Advantages. (Thesis). University of California – San Diego. Retrieved from http://www.escholarship.org/uc/item/6093h7s0

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Rupakula, Bhaskara Rao. “Millimeter-wave Phased-arrays for Communication and their System-Level Impairments and Advantages.” 2019. Thesis, University of California – San Diego. Accessed April 18, 2021. http://www.escholarship.org/uc/item/6093h7s0.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Rupakula, Bhaskara Rao. “Millimeter-wave Phased-arrays for Communication and their System-Level Impairments and Advantages.” 2019. Web. 18 Apr 2021.

Vancouver:

Rupakula BR. Millimeter-wave Phased-arrays for Communication and their System-Level Impairments and Advantages. [Internet] [Thesis]. University of California – San Diego; 2019. [cited 2021 Apr 18]. Available from: http://www.escholarship.org/uc/item/6093h7s0.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Rupakula BR. Millimeter-wave Phased-arrays for Communication and their System-Level Impairments and Advantages. [Thesis]. University of California – San Diego; 2019. Available from: http://www.escholarship.org/uc/item/6093h7s0

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

University of Illinois – Urbana-Champaign

13. Dave, Harshil H. Enhanced digital modulation of coherently coupled vertical cavity laser arrays: theory and application.

Degree: PhD, Electrical & Computer Engr, 2020, University of Illinois – Urbana-Champaign

URL: http://hdl.handle.net/2142/107925

► Dynamic properties of coherently coupled 2x1 vertical-cavity surface-emitting laser (VCSEL) arrays have been studied theoretically and experimentally. Directly modulated VCSELs are the dominant digital light… (more)

▼ Dynamic properties of coherently coupled 2x1 vertical-cavity surface-emitting laser (VCSEL) arrays have been studied theoretically and experimentally. Directly modulated VCSELs are the dominant digital light source in short-haul data communication links due to their low cost and low operating power. Due to the demand for faster internet speeds and high-performance data centers, there is an ever-increasing need for high-bandwidth, low-power, and low-cost laser sources. An ideal laser source would have data-rates exceeding 100 Gb/s, energy-per-bit ratios reaching less than 1 pJ/bit, and be fabricated/integrated using conventional methods. In this dissertation, monolithic 2x1 mutually phase-locked 850 nm VCSEL arrays, based on ion-implantation and photonic crystal design, are studied for high-speed datacom applications. From the theoretical perspective, coupled-mode rate equations are used to describe carrier-photon interactions in optically coupled semiconductor laser arrays. Bandwidth enhancement in phased laser arrays is explained using small-signal frequency-domain pole-zero analysis on coupled-mode rate equations. The effects of complex coupling coefficient, associated with index-antiguided and gain-guiding, on coupled laser dynamics, are explored. We study multiple modulation techniques, including single-, in-sync, and out-of-sync modulation using pole-zero analysis. We discover that bandwidth enhancement can be practically implemented using in-sync modulation of asymmetric arrays, which is experimentally verified. Dynamics surrounding PT-symmetry breaking and exceptional points are also studied using pole-zero analysis. By tuning the coupled lasers to an exceptional point, the array supermodes become indistinguishable, and the coupled-laser array forces the input signals into synchrony. Experimentally, we show progress on phased VCSEL arrays that can be designed to operate reliably through control of individual injection current to each laser element. In this manner, nearly all fabricated arrays can be biased to be mutually phase-locked. This dissertation attempts to visualize and characterize the locking region between two neighboring lasers by measuring far-field visibility to create a two-dimensional visibility map. Experimental data show that the locking region can be shifted or changed by ambient temperature, asymmetric array design, fabrication imperfections, and multimode operation. Additionally, the differential resistance, relative intensity noise, and harmonic distortion are measured to characterize the behavior of coherently coupled laser arrays in the locking region. Two-dimensional maps of total relative intensity noise and total harmonic distortion are created to visualize laser array dynamics in the locking region. We report high-speed digital modulation of 36 Gb/s by supplying the signal to both laser elements simultaneously. The resulting eye diagram is shown to be improved under coherent-coupling conditions. The analysis in this dissertation shows that the laser array must be carefully… Advisors/Committee Members: Choquette, Kent D (advisor), Choquette, Kent D (Committee Chair), Goddard, Lynford L (committee member), Schutt-Aine, José (committee member), Dragic, Peter (committee member).

Subjects/Keywords: Semiconductor lasers; phased arrays; Vertical-cavity surface-emitting lasers; optical communication

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APA (6^th Edition):

Dave, H. H. (2020). Enhanced digital modulation of coherently coupled vertical cavity laser arrays: theory and application. (Doctoral Dissertation). University of Illinois – Urbana-Champaign. Retrieved from http://hdl.handle.net/2142/107925

Chicago Manual of Style (16^th Edition):

Dave, Harshil H. “Enhanced digital modulation of coherently coupled vertical cavity laser arrays: theory and application.” 2020. Doctoral Dissertation, University of Illinois – Urbana-Champaign. Accessed April 18, 2021. http://hdl.handle.net/2142/107925.

MLA Handbook (7^th Edition):

Dave, Harshil H. “Enhanced digital modulation of coherently coupled vertical cavity laser arrays: theory and application.” 2020. Web. 18 Apr 2021.

Vancouver:

Dave HH. Enhanced digital modulation of coherently coupled vertical cavity laser arrays: theory and application. [Internet] [Doctoral dissertation]. University of Illinois – Urbana-Champaign; 2020. [cited 2021 Apr 18]. Available from: http://hdl.handle.net/2142/107925.

Council of Science Editors:

Dave HH. Enhanced digital modulation of coherently coupled vertical cavity laser arrays: theory and application. [Doctoral Dissertation]. University of Illinois – Urbana-Champaign; 2020. Available from: http://hdl.handle.net/2142/107925

University of Toronto

14. Marvasti, Mohammad Hassan. Development of Ultrasound Phased Array System for Weld Inspections at Elevated Temperatures.

Degree: PhD, 2014, University of Toronto

URL: http://hdl.handle.net/1807/68239

► Interruption of plant operation can be avoided if non destructive testing inspections are performed on-line at operating temperatures, which may be up to several hundred… (more)

Subjects/Keywords: beam skew; focal law; high temperatures; phased arrays; 0537

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APA (6^th Edition):

Marvasti, M. H. (2014). Development of Ultrasound Phased Array System for Weld Inspections at Elevated Temperatures. (Doctoral Dissertation). University of Toronto. Retrieved from http://hdl.handle.net/1807/68239

Chicago Manual of Style (16^th Edition):

Marvasti, Mohammad Hassan. “Development of Ultrasound Phased Array System for Weld Inspections at Elevated Temperatures.” 2014. Doctoral Dissertation, University of Toronto. Accessed April 18, 2021. http://hdl.handle.net/1807/68239.

MLA Handbook (7^th Edition):

Marvasti, Mohammad Hassan. “Development of Ultrasound Phased Array System for Weld Inspections at Elevated Temperatures.” 2014. Web. 18 Apr 2021.

Vancouver:

Marvasti MH. Development of Ultrasound Phased Array System for Weld Inspections at Elevated Temperatures. [Internet] [Doctoral dissertation]. University of Toronto; 2014. [cited 2021 Apr 18]. Available from: http://hdl.handle.net/1807/68239.

Council of Science Editors:

Marvasti MH. Development of Ultrasound Phased Array System for Weld Inspections at Elevated Temperatures. [Doctoral Dissertation]. University of Toronto; 2014. Available from: http://hdl.handle.net/1807/68239

University of Illinois – Urbana-Champaign

15. Fryslie, Stewart T. Modulation of coherently coupled surface-emitting laser arrays: analysis and applications.

Degree: PhD, Electrical & Computer Engr, 2017, University of Illinois – Urbana-Champaign

URL: http://hdl.handle.net/2142/97293

► Vertical-cavity surface-emitting lasers (VCSELs) have become the dominant source for optical data communication links in computer server, data center, and super computer applications. Driven by… (more)

▼ Vertical-cavity surface-emitting lasers (VCSELs) have become the dominant source for optical data communication links in computer server, data center, and super computer applications. Driven by the exponential increase of performance in information technology, data centers, and computational power, data transmission bandwidth is required to increase exponentially as well. Furthermore, as data centers become physically larger, utilizing more interconnects and requiring longer rack-to-rack fiber transmission distance, low power consumption and narrow spectral width for reduced signal dispersion become increasingly important. This work discusses the development of phased, ion-implanted, PhC VCSEL arrays for coherently coupled operation and modulation bandwidth enhancement with narrow spectral width emission. In this dissertation, monolithic mutual optical injection locking induced laser dynamics in phased, coherently coupled implant-defined PhC VCSEL arrays are investigated in detail both theoretically and experimentally. A model based on the well-established injection-locking laser rate equations is used to intuitively explain the physics of various experimental phenomena. An operation procedure, in which current isolation and bias conditions are leveraged to control array index profile and coupling phase, is developed to achieve coherently coupled operation of the phased VCSEL arrays reproducibly with high yield. An experimental study on the modulation characteristics and locking range dynamics of coherently coupled VCSEL arrays is conducted, showing significant improvements in operational procedures, performance, and device manufacturing. A record VCSEL 3 dB bandwidth of 37 GHz (receiver limited) is obtained under highly single-mode coherent operation with narrow spectral width and increased output power while the laser array is biased at low current density. Additionally, this result has been duplicated by multiple devices, under coherently coupled operation in either the in-phase or out-of-phase mode. Bandwidth enhancement beyond 30 GHz has been shown to be reproducible for several different photonic crystal patterns, and bias conditions for bandwidth enhancement have been shown to be stable and reproducible for the same device design across the sample. Advisors/Committee Members: Choquette, Kent (advisor), Choquette, Kent (Committee Chair), Schutt-Aine, Jose (committee member), Goddard, Lynford (committee member), Dragic, Peter (committee member).

Subjects/Keywords: Semiconductor lasers; Phased arrays; Vertical-cavity surface-emitting lasers; Optical communications

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APA (6^th Edition):

Fryslie, S. T. (2017). Modulation of coherently coupled surface-emitting laser arrays: analysis and applications. (Doctoral Dissertation). University of Illinois – Urbana-Champaign. Retrieved from http://hdl.handle.net/2142/97293

Chicago Manual of Style (16^th Edition):

Fryslie, Stewart T. “Modulation of coherently coupled surface-emitting laser arrays: analysis and applications.” 2017. Doctoral Dissertation, University of Illinois – Urbana-Champaign. Accessed April 18, 2021. http://hdl.handle.net/2142/97293.

MLA Handbook (7^th Edition):

Fryslie, Stewart T. “Modulation of coherently coupled surface-emitting laser arrays: analysis and applications.” 2017. Web. 18 Apr 2021.

Vancouver:

Fryslie ST. Modulation of coherently coupled surface-emitting laser arrays: analysis and applications. [Internet] [Doctoral dissertation]. University of Illinois – Urbana-Champaign; 2017. [cited 2021 Apr 18]. Available from: http://hdl.handle.net/2142/97293.

Council of Science Editors:

Fryslie ST. Modulation of coherently coupled surface-emitting laser arrays: analysis and applications. [Doctoral Dissertation]. University of Illinois – Urbana-Champaign; 2017. Available from: http://hdl.handle.net/2142/97293

University of Arizona

16. Pat, Terrance. Electronically Steerable Inflatable Antennas .

Degree: 2017, University of Arizona

URL: http://hdl.handle.net/10150/626342

► In today’s technologically driven world, antennas play an essential role in enabling wireless communications over long distances and allow communities to interact on a global… (more)

Subjects/Keywords: Antennas; CubeSats; Microwave Engineering; Phased Arrays; Satellite Communications; Telecommunications

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APA (6^th Edition):

Pat, T. (2017). Electronically Steerable Inflatable Antennas . (Masters Thesis). University of Arizona. Retrieved from http://hdl.handle.net/10150/626342

Chicago Manual of Style (16^th Edition):

Pat, Terrance. “Electronically Steerable Inflatable Antennas .” 2017. Masters Thesis, University of Arizona. Accessed April 18, 2021. http://hdl.handle.net/10150/626342.

MLA Handbook (7^th Edition):

Pat, Terrance. “Electronically Steerable Inflatable Antennas .” 2017. Web. 18 Apr 2021.

Vancouver:

Pat T. Electronically Steerable Inflatable Antennas . [Internet] [Masters thesis]. University of Arizona; 2017. [cited 2021 Apr 18]. Available from: http://hdl.handle.net/10150/626342.

Council of Science Editors:

Pat T. Electronically Steerable Inflatable Antennas . [Masters Thesis]. University of Arizona; 2017. Available from: http://hdl.handle.net/10150/626342

Virginia Tech

17. Baggett, Benjamin Matthew Wall. Optimization of Aperiodically Spaced Antenna Arrays for Wideband Applications.

Degree: MS, Electrical and Computer Engineering, 2011, Virginia Tech

URL: http://hdl.handle.net/10919/32532

► Over the years, phased array antennas have provided electronic scanning with high gain and low sidelobe levels for many radar and satellite applications. The need… (more)

Subjects/Keywords: optimization; helix; phased arrays; wideband; aperiodic; Particle Swarm Optimization

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APA (6^th Edition):

Baggett, B. M. W. (2011). Optimization of Aperiodically Spaced Antenna Arrays for Wideband Applications. (Masters Thesis). Virginia Tech. Retrieved from http://hdl.handle.net/10919/32532

Chicago Manual of Style (16^th Edition):

Baggett, Benjamin Matthew Wall. “Optimization of Aperiodically Spaced Antenna Arrays for Wideband Applications.” 2011. Masters Thesis, Virginia Tech. Accessed April 18, 2021. http://hdl.handle.net/10919/32532.

MLA Handbook (7^th Edition):

Baggett, Benjamin Matthew Wall. “Optimization of Aperiodically Spaced Antenna Arrays for Wideband Applications.” 2011. Web. 18 Apr 2021.

Vancouver:

Baggett BMW. Optimization of Aperiodically Spaced Antenna Arrays for Wideband Applications. [Internet] [Masters thesis]. Virginia Tech; 2011. [cited 2021 Apr 18]. Available from: http://hdl.handle.net/10919/32532.

Council of Science Editors:

Baggett BMW. Optimization of Aperiodically Spaced Antenna Arrays for Wideband Applications. [Masters Thesis]. Virginia Tech; 2011. Available from: http://hdl.handle.net/10919/32532

University of Arizona

18. Pat, Terrance. Implementation and Design of Spherical High-Gain Antennas .

Degree: 2020, University of Arizona

URL: http://hdl.handle.net/10150/648586

► Rapid advances in telecommunications are occurring for both space-based and ground-based antenna systems. Space-based advances in communications include the rise in using constellations of inexpensive… (more)

Subjects/Keywords: Beamsteering; CubeSats; Inflatables; Phased Arrays; Polarization; Spherical Reflector

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APA (6^th Edition):

Pat, T. (2020). Implementation and Design of Spherical High-Gain Antennas . (Doctoral Dissertation). University of Arizona. Retrieved from http://hdl.handle.net/10150/648586

Chicago Manual of Style (16^th Edition):

Pat, Terrance. “Implementation and Design of Spherical High-Gain Antennas .” 2020. Doctoral Dissertation, University of Arizona. Accessed April 18, 2021. http://hdl.handle.net/10150/648586.

MLA Handbook (7^th Edition):

Pat, Terrance. “Implementation and Design of Spherical High-Gain Antennas .” 2020. Web. 18 Apr 2021.

Vancouver:

Pat T. Implementation and Design of Spherical High-Gain Antennas . [Internet] [Doctoral dissertation]. University of Arizona; 2020. [cited 2021 Apr 18]. Available from: http://hdl.handle.net/10150/648586.

Council of Science Editors:

Pat T. Implementation and Design of Spherical High-Gain Antennas . [Doctoral Dissertation]. University of Arizona; 2020. Available from: http://hdl.handle.net/10150/648586

Georgia Tech

19. May, Max Philipp. Proposal and analysis of a non-collinear wave mixing technique for the detection of micro-cracks using phased arrays.

Degree: MS, Civil and Environmental Engineering, 2020, Georgia Tech

URL: http://hdl.handle.net/1853/64085

► In this thesis, a new ultrasonic measurement setup for the detection of micro-scale damage in cement based materials is proposed and analyzed. The idea is… (more)

▼ In this thesis, a new ultrasonic measurement setup for the detection of micro-scale damage in cement based materials is proposed and analyzed. The idea is to use the nonlinear phenomenon of wave mixing to characterize third order elastic behavior of a material. By wave mixing, the nonlinear interaction between two ultrasound waves creating a third resonant wave inside a material is meant. The amplitude of this third wave is dependent on the third order nonlinear constants of a material, which in turn are influenced by micro-scale damage inside the material structure. Furthermore, a nonlinear technique is especially needed in the case of attenuative materials, which prevent the use of higher frequencies to get good resolution with linear approaches. Recent measurement results using a wave mixing technique are designed in a fixed setup to evalute a single point inside the material or scan line regions by moving the ultrasonic equipment. This limitation originates from the use of common ultrasonic transducer elements generating an ultrasound wave at a fixed angle by using the refraction of wedges. As a remedy to this limitation, phased arrays can be used as a source for the incident waves instead. Thus, having the advantage to change the beam angle without changing the physical measurement configuration. Two phased arrays are used on one side of the specimen to generate incident shear waves. If the the beams intersect inside the material at a point fulfilling certain mixing conditions, a longitudinal resonant wave is generated which amplitude is proportional to the amount of nonlinearity inherent to the mixing volume. This resonant wave can be measured by a receiver on the other side of the material to asses, e.g., micro-crack density in the mixing volume. \par In this thesis, necessary and sufficient conditions for this non-collinear shear wave mixing are derived. Furthermore, the basic laws for beam steering with phased arrays are explained and the mixing volume is modeled. Finally, advantages and limitations of this measurement technique as well as design specifics for the practical construction of a measurement setup are discussed. Advisors/Committee Members: Jacobs, Laurence J (advisor), Kim, Jin-Yeon (advisor), Valle, Christine (committee member).

Subjects/Keywords: Non destructive evaluation; micro-cracks; phased arrays; wave mixing

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APA (6^th Edition):

May, M. P. (2020). Proposal and analysis of a non-collinear wave mixing technique for the detection of micro-cracks using phased arrays. (Masters Thesis). Georgia Tech. Retrieved from http://hdl.handle.net/1853/64085

Chicago Manual of Style (16^th Edition):

May, Max Philipp. “Proposal and analysis of a non-collinear wave mixing technique for the detection of micro-cracks using phased arrays.” 2020. Masters Thesis, Georgia Tech. Accessed April 18, 2021. http://hdl.handle.net/1853/64085.

MLA Handbook (7^th Edition):

May, Max Philipp. “Proposal and analysis of a non-collinear wave mixing technique for the detection of micro-cracks using phased arrays.” 2020. Web. 18 Apr 2021.

Vancouver:

May MP. Proposal and analysis of a non-collinear wave mixing technique for the detection of micro-cracks using phased arrays. [Internet] [Masters thesis]. Georgia Tech; 2020. [cited 2021 Apr 18]. Available from: http://hdl.handle.net/1853/64085.

Council of Science Editors:

May MP. Proposal and analysis of a non-collinear wave mixing technique for the detection of micro-cracks using phased arrays. [Masters Thesis]. Georgia Tech; 2020. Available from: http://hdl.handle.net/1853/64085

20. Fourtinon, L. 3D conformal antennas for radar applications.

Degree: 2018, Cranfield University

URL: http://dspace.lib.cranfield.ac.uk/handle/1826/13359

► Embedded below the radome of a missile, existing RF-seekers use a mechanical rotating antenna to steer the radiating beam in the direction of a target.… (more)

Subjects/Keywords: Conformal; Phased arrays; Ellipticity

…adapted to non-identical quadrants is also proposed. Keywords: conformal, 3D, phased arrays… …2.3.2. Polarisation and methodology of analysis of conformal arrays . . 49 2.3.2.1… …the 3D conformal arrays . . . . . . . . . . . . 61 2.4. Introduction to the CRLB and… …CRLB . . . . . . . . . . . . . . . . . . . . 71 3. Study of planar and 3D/conformal arrays… …87 3.3. Polarisation analysis of planar arrays . . . . . . . . . . . . . . . . . . . 91…

10 more images…

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APA (6^th Edition):

Fourtinon, L. (2018). 3D conformal antennas for radar applications. (Thesis). Cranfield University. Retrieved from http://dspace.lib.cranfield.ac.uk/handle/1826/13359

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Fourtinon, L. “3D conformal antennas for radar applications.” 2018. Thesis, Cranfield University. Accessed April 18, 2021. http://dspace.lib.cranfield.ac.uk/handle/1826/13359.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Fourtinon, L. “3D conformal antennas for radar applications.” 2018. Web. 18 Apr 2021.

Vancouver:

Fourtinon L. 3D conformal antennas for radar applications. [Internet] [Thesis]. Cranfield University; 2018. [cited 2021 Apr 18]. Available from: http://dspace.lib.cranfield.ac.uk/handle/1826/13359.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Fourtinon L. 3D conformal antennas for radar applications. [Thesis]. Cranfield University; 2018. Available from: http://dspace.lib.cranfield.ac.uk/handle/1826/13359

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Hong Kong University of Science and Technology

21. Zhang, Ge. Design of frequency dependent beam steering antennas and arrays.

Degree: 2020, Hong Kong University of Science and Technology

URL: http://repository.ust.hk/ir/Record/1783.1-109064 ; https://doi.org/10.14711/thesis-991012879859403412 ; http://repository.ust.hk/ir/bitstream/1783.1-109064/1/th_redirect.html

► In the last decade the application of beam steering antennas and arrays to microwave and millimeter wave imaging for breast cancer detection, contactless security check… (more)

Subjects/Keywords: Phased array antennas ; Antenna arrays ; Antennas, Reflector ; Surface wave antennas

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APA (6^th Edition):

Zhang, G. (2020). Design of frequency dependent beam steering antennas and arrays. (Thesis). Hong Kong University of Science and Technology. Retrieved from http://repository.ust.hk/ir/Record/1783.1-109064 ; https://doi.org/10.14711/thesis-991012879859403412 ; http://repository.ust.hk/ir/bitstream/1783.1-109064/1/th_redirect.html

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Zhang, Ge. “Design of frequency dependent beam steering antennas and arrays.” 2020. Thesis, Hong Kong University of Science and Technology. Accessed April 18, 2021. http://repository.ust.hk/ir/Record/1783.1-109064 ; https://doi.org/10.14711/thesis-991012879859403412 ; http://repository.ust.hk/ir/bitstream/1783.1-109064/1/th_redirect.html.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Zhang, Ge. “Design of frequency dependent beam steering antennas and arrays.” 2020. Web. 18 Apr 2021.

Vancouver:

Zhang G. Design of frequency dependent beam steering antennas and arrays. [Internet] [Thesis]. Hong Kong University of Science and Technology; 2020. [cited 2021 Apr 18]. Available from: http://repository.ust.hk/ir/Record/1783.1-109064 ; https://doi.org/10.14711/thesis-991012879859403412 ; http://repository.ust.hk/ir/bitstream/1783.1-109064/1/th_redirect.html.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Zhang G. Design of frequency dependent beam steering antennas and arrays. [Thesis]. Hong Kong University of Science and Technology; 2020. Available from: http://repository.ust.hk/ir/Record/1783.1-109064 ; https://doi.org/10.14711/thesis-991012879859403412 ; http://repository.ust.hk/ir/bitstream/1783.1-109064/1/th_redirect.html

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

22. Sanchez-Barbetty, Mauricio. Low Cost Electronically Steered Phase Arrays for Weather Applications.

Degree: PhD, Electrical and Computer Engineering, 2011, U of Massachusetts : PhD

URL: https://scholarworks.umass.edu/open_access_dissertations/343

► The Electronically Steered Phased Array is one of the most versatile antennas used in radars applications. Some of the advantages of electronic steering are… (more)

▼ The Electronically Steered Phased Array is one of the most versatile antennas used in radars applications. Some of the advantages of electronic steering are faster scan, no moving parts and higher reliability. However, the cost of phased arrays has always been prohibitive - in the order of $1M per square meter. The cost of a phased array is largely impacted by the cost of the high frequency electronics at each element and the cost of packaging. Advances in IC integration will allow incorporating multiple elements such as low noise amplifier, power amplifier, phase shifters and up/down-conversion into one or two ICs. Even though the cost for large quantities of ICs (both Silicon and GaAs) has lowered, the high cost of IC packaging and the array backplane still make the use of phase arrays for radar applications costly. The focus of this research is on techniques that reduce the packaging and the backplane cost of large electronically steered arrays. These techniques are based on simplified signal distributions schemes, reduction of layers in the backplane and use of inexpensive materials. Two architectures designed based on these techniques, as well as a novel BGA active antenna package for dual polarized phased arrays are presented. The first architecture, called the series fed row-column architecture, focuses on the reduction of phase shifters and control signals used in the backplane of the array. The second architecture, called the parallel plate feed architecture, is based on a simplified scheme for distribution of the local oscillator signal. A prototype making use of each one of these architectures is presented. Analysis of advantages and disadvantages of each of these architectures is described. The necessity of cost reduction is a factor that can possibly impact the polarization performance of the antenna. This factor is a motivation to study and develop calibration techniques that reduce the cross-polarization of electronically steered phased arrays. Advances on Interleaving Sparse Arrays, a beam forming technique for polarization improvement/correction in phased arrays, are also presented. Advisors/Committee Members: Robert W. Jackson, Stephen Frasier, Daniel H. Schaubert.

Subjects/Keywords: dual polarization; electronically scanned arrays; parallel plate; phased arrays; polarization; row-column; Electrical and Computer Engineering

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Sanchez-Barbetty, M. (2011). Low Cost Electronically Steered Phase Arrays for Weather Applications. (Doctoral Dissertation). U of Massachusetts : PhD. Retrieved from https://scholarworks.umass.edu/open_access_dissertations/343

Chicago Manual of Style (16^th Edition):

Sanchez-Barbetty, Mauricio. “Low Cost Electronically Steered Phase Arrays for Weather Applications.” 2011. Doctoral Dissertation, U of Massachusetts : PhD. Accessed April 18, 2021. https://scholarworks.umass.edu/open_access_dissertations/343.

MLA Handbook (7^th Edition):

Sanchez-Barbetty, Mauricio. “Low Cost Electronically Steered Phase Arrays for Weather Applications.” 2011. Web. 18 Apr 2021.

Vancouver:

Sanchez-Barbetty M. Low Cost Electronically Steered Phase Arrays for Weather Applications. [Internet] [Doctoral dissertation]. U of Massachusetts : PhD; 2011. [cited 2021 Apr 18]. Available from: https://scholarworks.umass.edu/open_access_dissertations/343.

Council of Science Editors:

Sanchez-Barbetty M. Low Cost Electronically Steered Phase Arrays for Weather Applications. [Doctoral Dissertation]. U of Massachusetts : PhD; 2011. Available from: https://scholarworks.umass.edu/open_access_dissertations/343

Penn State University

23. Koduru, Jaya Prakash. Ultrasonic guided wave phased arrays for defect detection in plate like structures .

Degree: 2010, Penn State University

URL: https://submit-etda.libraries.psu.edu/catalog/11165

► The primary aim of this thesis is to develop guided wave phased array technology to inspect plates and plate-like structures. The thesis covers aspects of… (more)

▼ The primary aim of this thesis is to develop guided wave phased array technology to inspect plates and plate-like structures. The thesis covers aspects of guided wave mechanics, transducer design and phased array development for plates. Metallic and carbon fiber reinforced composite plates are considered for inspection. The long range propagation characteristics of guided waves combined with the capability of beamforming in a direction of interest significantly increases the probability of detecting defects in large structures and to localize them. Free wave modal solutions for the guided wave modes in a structure are obtained using the semi-analytical finite element (SAFE) method. The directional dependent dispersion curves in composite laminates are calculated and other guided wave properties like the skew angle, phase velocity, energy velocity and mode excitabilities are computed. The guided wave mode properties are used as input in transducer design. Analytical expressions are developed to obtain the wave field in plates due to arbitrary loading. Using these analytical expressions guided wave fields due to array transducers are calculated. At any frequency there can exist several guided wave modes in a structure that complicates the analysis. Annular array transducers are designed to excite individual omni-directional guided wave modes in plate like structures. The mathematical expressions are derived to analytically express the guided wave field excited in a structure due to annular arrays, the optimum parameters needed to excite a single guided wave mode are derived and utilized in the design of transducers. Annular array transducers are designed and tested for applications in SHM. The problem of water loading on structures being monitored for corrosion is successfully overcome by proper design of annular array transducers. Phased annular array transducers are studied to overcome the limitations of annular array transducers. Mathematically, the problem needed to optimize the array parameters for uni-modal guided wave generation is established. 1-3 piezocomposite materials are studied for developing array transducers. The low lateral coupling between array elements in 1-3 piezocomposites is utilized in the design of phased annular array transducers. The designed transducers are successfully tested for their uni-modal generation capability. Phased array principles commonly used in ultrasound imaging systems and Radar systems are studied. The phased array principles are adapted to plate like structures to enable guided wave beamforming. Linear and circular arrays are studied, the array parameters namely the element spacing and aperture illumination are studied for their influence on beamforming. The influence of unwanted modes on the beamforming is studied and techniques to suppress the unwanted modes are implemented. A phased annular beamformer transducer is developed for guided wave mode control and beamforming to a given direction. Using 1-3 piezocomposites, the phased annular beamformer transducer is… Advisors/Committee Members: Joseph Lawrence Rose, Dissertation Advisor/Co-Advisor, Joseph Lawrence Rose, Committee Chair/Co-Chair, Clifford Jesse Lissenden Iii, Committee Member, Bernhard R Tittmann, Committee Member, Thomas R Shrout, Committee Member, Judith Todd Copley, Committee Chair/Co-Chair.

Subjects/Keywords: piezocomposites; annular arrays; phased arrays; guided waves

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APA (6^th Edition):

Koduru, J. P. (2010). Ultrasonic guided wave phased arrays for defect detection in plate like structures . (Thesis). Penn State University. Retrieved from https://submit-etda.libraries.psu.edu/catalog/11165

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Koduru, Jaya Prakash. “Ultrasonic guided wave phased arrays for defect detection in plate like structures .” 2010. Thesis, Penn State University. Accessed April 18, 2021. https://submit-etda.libraries.psu.edu/catalog/11165.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Koduru, Jaya Prakash. “Ultrasonic guided wave phased arrays for defect detection in plate like structures .” 2010. Web. 18 Apr 2021.

Vancouver:

Koduru JP. Ultrasonic guided wave phased arrays for defect detection in plate like structures . [Internet] [Thesis]. Penn State University; 2010. [cited 2021 Apr 18]. Available from: https://submit-etda.libraries.psu.edu/catalog/11165.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Koduru JP. Ultrasonic guided wave phased arrays for defect detection in plate like structures . [Thesis]. Penn State University; 2010. Available from: https://submit-etda.libraries.psu.edu/catalog/11165

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Univerzitet u Beogradu

24. Vukmirović, Nenad J., 1988-, 54589193. Кохерентна директна локализација у дистрибуираним масивним вишеантенским системима.

Degree: Elektrotehnički fakultet, 2020, Univerzitet u Beogradu

URL: https://fedorabg.bg.ac.rs/fedora/get/o:22308/bdef:Content/get

►

Elektrotehnika - Telekomunikacije / Electrical Engineering - Telecommunications

Disertacija se bavi problemom direktne koherentne lokalizacije izvora xirokopojasnih radio signala pomou masivnih vixeantenskih sistemima u prostorno… (more)

▼

Elektrotehnika - Telekomunikacije / Electrical Engineering - Telecommunications

Disertacija se bavi problemom direktne koherentne lokalizacije izvora xirokopojasnih radio signala pomou masivnih vixeantenskih sistemima u prostorno koherentnom scenariju LOS (Line-OfSight) komponenti. Ovaj scenario je tipiqan za male elije u milimetarskom opsegu u petoj generaciji 5G elijskih sistema. Lokalizacija se zasniva na obradi signala sa distribuiranih antenskih nizova koji mogu imati podnizove sa faziranim antenskim rexetkama. Ideja ove disertacije je da se infrastruktura buduih beiqnih sistema pete generacije (5G) iskoristi, pored komunikacije, i za lokalizaciju koja je predmet disertacije. Ciǉ je da se ostvari prezicnost procene pozicije za 2 do 3 reda veliqine boǉu od talasne duine nosioca, xto klasiqne metode za dvokoraqnu i jednokoraqnu (direktnu) lokalizaciju ne omoguavaju. Da bi se to postiglo, koriste se koherentne metode { one koje pored pomaka anvelopa koriste i informacije sadrane u fazama nosioca LOS komponenti. Da bi se to moglo iskoristiti, potrebno je da u eliji postoji prostorna koherencija LOS komponenti. Zbog toga se istraivaǌe pre svega oslaǌa na male elije (sa LOS uslovima) i milimetarski (mmWave) opseg (koji ima povoǉne uslove prostiraǌa), ali nije ograniqeno na ǌih dok god je prethodni uslov zadovoǉen. Korixene su sledee metode istraivaǌa. Matematiqki je modelovan prostorno koherentni scenario i za ǌega su izvedene teorijske granice preciznosti lokalizacije. Zatim su predloene metode lokalizacije. ǋihove performanse su analizirane simulacijama i eksperimentalno. Za eksperimente je korixen hardver koji je napravǉen u sklopu istraivaǌa. Izvedene su Kramer-Raove granice preciznosti lokalizacije za model signala u prostorno koherentnom scenariju i pokazano je da su obrnuto srazmerne kvadratu frekvencije nosioca. Predloeno je vixe tipova metoda za lokalizaciju { nekoherentne, polukoherentne i koherentne; metode za poznatu sekvencu (kooperativan predajnik/korisnik) i za nepoznatu (nekooperativan predajnik); metode maksimalne verodostojnosti izvedene za jednokorisniqki potpuni LOS sluqaj i potprostorne metode. Predloene koherentne metode su statistiqki efikasne (ǌihova preciznost dostie izvedene teorijske granice) i ostvaruju preciznost za 2 do 3 reda veliqine boǉu od talasne duine nosioca. Analiziran je i sluqaj vixestrukog prostiraǌa, a metode i tada ostvaruju preciznost za 2 reda veliqine boǉu od talasne duine. Takoe funkcionixu u scenariju sa vixe (i to prostorno bliskih) predajnika pribline snage. Pritom, potprostorne metode funkcionixu i kad je interferirajui predajnik za 30 dB vee snage od ciǉanog. Svi ovi rezultati su ostvareni za razumne vrednosti sistemskih parametara, kao xto su odnosi signal-xum i broj odbiraka. Pored toga, algoritmi funkcionixu i pri malim odnosima signal-xum, zahvaǉujui tome xto direktno na osnovu sirovih signala proceǌuju poziciju, za razliku od klasiqnih metoda koje gube informacije pravei meuprocene. Dodatna povoǉnost direktne lokalizacije je xto se izbegava numeriqki zahtevan…

Advisors/Committee Members: Erić, Miljko, 1955-, 17471335.

Subjects/Keywords: wideband direct localization; spatial coherence; distributed antenna arrays; Cram´er-Rao bound; mmWave; massive MIMO; phased antenna arrays

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APA (6^th Edition):

Vukmirović, Nenad J., 1988-, 5. (2020). Кохерентна директна локализација у дистрибуираним масивним вишеантенским системима. (Thesis). Univerzitet u Beogradu. Retrieved from https://fedorabg.bg.ac.rs/fedora/get/o:22308/bdef:Content/get

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Vukmirović, Nenad J., 1988-, 54589193. “Кохерентна директна локализација у дистрибуираним масивним вишеантенским системима.” 2020. Thesis, Univerzitet u Beogradu. Accessed April 18, 2021. https://fedorabg.bg.ac.rs/fedora/get/o:22308/bdef:Content/get.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Vukmirović, Nenad J., 1988-, 54589193. “Кохерентна директна локализација у дистрибуираним масивним вишеантенским системима.” 2020. Web. 18 Apr 2021.

Vancouver:

Vukmirović, Nenad J., 1988- 5. Кохерентна директна локализација у дистрибуираним масивним вишеантенским системима. [Internet] [Thesis]. Univerzitet u Beogradu; 2020. [cited 2021 Apr 18]. Available from: https://fedorabg.bg.ac.rs/fedora/get/o:22308/bdef:Content/get.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Vukmirović, Nenad J., 1988- 5. Кохерентна директна локализација у дистрибуираним масивним вишеантенским системима. [Thesis]. Univerzitet u Beogradu; 2020. Available from: https://fedorabg.bg.ac.rs/fedora/get/o:22308/bdef:Content/get

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

University of California – San Diego

25. Kanar, Tumay. Built-in-Self-Test Circuits for Wideband Phased Arrays and Circuits for Millimeter-wave Radiometry and Low-noise Applications.

Degree: Electrical Engineering (Electronic Circuits and Systems), 2015, University of California – San Diego

URL: http://www.escholarship.org/uc/item/2sj4j7jg

► The thesis presents wide-band built-in self-test circuits (BIST) for phased array systems and high performance circuits for millimeter-wave radiometry and low-noise applications. The 2-15 GHz… (more)

▼ The thesis presents wide-band built-in self-test circuits (BIST) for phased array systems and high performance circuits for millimeter-wave radiometry and low-noise applications. The 2-15 GHz BIST is designed using a resistive wide-band coupler at the input of each channel and an on-chip oscillator is employed for the test signal and local oscillator generation. An on-chip 8-phase self-correcting I/Q vector receiver and algorithm are introduced for wide-band accuracy. Using the I/Q outputs from 8 different LO phases for one-time calibration, the DC offset, gain and phase imbalance for the system can be determined at each frequency point and eliminated. The BIST can be done at a rate of 1 MHz with greater than 50 dB signal-to-noise-ratio (SNR) and allows for accurate characterization of the phased array by providing relative gain and phase measurements over a wide frequency range. The BIST results agree well with the VNA measurements, and the 2-15 GHz BIST can determine the channel's relative phase and gain error with 3 and 0.3 dB accuracy, respectively. An RMS detector network is also implemented for absolute gain measurements, and the absolute gain is measured using a pair of detectors located at the input and the output ports. The BIST can measure the absolute gain with 0.5 dB accuracy at 2-15 GHz, and this feature can be employed to detect under-performing units in the field for self-healing mechanisms.Next, a D-band radiometer centered at 136 GHz is presented. The radiometer is realized with a 35 dB gain low-noise amplifier and a detector in the IBM 90 nm SiGe BiCMOS process. The on-chip radiometer results in a measured minimum NEP of 1.4 fW/Hz1/2 and a peak responsivity of 52 MV/W. With a low 1/f corner frequency (<100 Hz) and a noise bandwidth >10 GHz, this system is suitable for high-resolution imaging applications. For an integration time of 3.125 mS, the minimum noise equivalent temperature difference (NETD) is measured to be 0.25K using different independent methods and is the lowest NETD demonstrated in silicon technologies at D-band frequencies.Finally, X- and K-band low-noise amplifiers (LNA) in a 0.18 μm SiGe BiCMOS process are presented with measured mean noise figure of 1.2 dB and 2.2 dB, respectively. A method of noise match optimization with respect to base inductance in SiGe LNA design with large transistors is proposed and explained in detail. The LNAs result in peak gain of 24.2 and 19 dB at 8.5 and 19.5 GHz and IIP3 of -11 and -4 dBm at 10 and 20 GHz, respectively. To the authors' best knowledge, these results outperform all available CMOS designs and achieve the lowest mean noise figure at X- and K-bands in any SiGe or CMOS process at the time of publication. Another K-band LNA is also implemented in 45 nm IBM CMOS SOI process and results in 2.2 dB mean noise figure with 19 dB peak gain. The details of this design are presented in the appendix.

Subjects/Keywords: Electrical engineering; built-in self-test; low noise amplifiers; millimeter wave imaging; phased arrays; radiometer

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APA (6^th Edition):

Kanar, T. (2015). Built-in-Self-Test Circuits for Wideband Phased Arrays and Circuits for Millimeter-wave Radiometry and Low-noise Applications. (Thesis). University of California – San Diego. Retrieved from http://www.escholarship.org/uc/item/2sj4j7jg

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Kanar, Tumay. “Built-in-Self-Test Circuits for Wideband Phased Arrays and Circuits for Millimeter-wave Radiometry and Low-noise Applications.” 2015. Thesis, University of California – San Diego. Accessed April 18, 2021. http://www.escholarship.org/uc/item/2sj4j7jg.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Kanar, Tumay. “Built-in-Self-Test Circuits for Wideband Phased Arrays and Circuits for Millimeter-wave Radiometry and Low-noise Applications.” 2015. Web. 18 Apr 2021.

Vancouver:

Kanar T. Built-in-Self-Test Circuits for Wideband Phased Arrays and Circuits for Millimeter-wave Radiometry and Low-noise Applications. [Internet] [Thesis]. University of California – San Diego; 2015. [cited 2021 Apr 18]. Available from: http://www.escholarship.org/uc/item/2sj4j7jg.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Kanar T. Built-in-Self-Test Circuits for Wideband Phased Arrays and Circuits for Millimeter-wave Radiometry and Low-noise Applications. [Thesis]. University of California – San Diego; 2015. Available from: http://www.escholarship.org/uc/item/2sj4j7jg

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

University of California – San Diego

26. Avser, Bilgehan. Frequency Tunable Antennas and Novel Phased Array Feeding Networks for Next Generation Communication Systems.

Degree: Electrical Engineering (Electronic Circuits and Systems), 2015, University of California – San Diego

URL: http://www.escholarship.org/uc/item/6cq329s4

► The thesis presents three dual-band frequency tunable antennas for carrier aggregation systems and two new feeding networks for reducing the number of phase shifters in… (more)

▼ The thesis presents three dual-band frequency tunable antennas for carrier aggregation systems and two new feeding networks for reducing the number of phase shifters in limited-scan arrays. First, single- and dual-feed, dual-frequency, low-profile antennas with independent frequency tuning using varactor diodes are presented. The dual-feed planar inverted F-antenna (PIFA) has two operating frequencies which are independently tuned at 0.7 – 1.1 GHz and at 1.7 – 2.3 GHz with better than −10 dB impedance match. The isolation between the high-band and the low-band ports is > 13 dB; hence, one resonant frequency can be tuned without affecting the other. The single-feed contiguous-dual-band antenna has two resonant frequencies, which are independently tuned at 1.2 – 1.6 GHz at 1.6 – 2.3 GHz with better than −10 dB impedance match for most of the tuning range. And the single-feed dual-band antenna has two resonant frequencies, which are independently tuned at 0.7 – 1.0 GHz at 1.7 – 2.3 GHz with better than −10 dB impedance match for most of the tuning range. The tuning is done using varactor diodes with a capacitance range from 0.8 to 3.8 pF, which is compatible with RF MEMS devices. The antenna volumes are 63 × 100 × 3.15 mm³ on ε_r = 3.55 substrates and the measured antenna efficiencies vary between 25% and 50% over the tuning range. The application areas are in carrier aggregation systems for fourth generation (4G) wireless systems. Next, a new phased array feeding network that employs random sequences of non-uniform sub-arrays (and a single phase shifter for each sub-array) is presented. When these sequences are optimized, the resulting phased arrays can scan over a wide region with low sidelobe levels. Equations for analyzing the random arrays and an algorithm for optimizing the array sequences are presented. Multiple random-solutions with different number of phase shifters and different set of sub-array groups are analyzed and design guidelines are presented. The performance of the random array feeding scheme is compared to the conventional uniform sub-arraying for multiple cases. It is shown that with the random feeding networks, the number of phase shifters can be reduced up to 30% while preserving the system performance. This results in more affordable and more reliable systems. The proposed feeding network is demonstrated for a 30 element array of slot- fed patch antennas at 7.9 GHz. The fabricated array uses 12 phase shifters, has a half power beamwidth (HPBW) of 4^o and can scan up to ± 14^o with sidelobe levels less than -15 dB.Another phase shifter reducing method, the interwoven feeding networks, is investigated. These passive feeding networks are composed of power dividers, couplers and resistive attenuators. In this configuration, each phase shifter feeds all of the antennas and creates a sinc-like current distribution over the array elements which results in a boxcar function-like element pattern. This element pattern is used to cancel the grating lobes. By changing the…

Subjects/Keywords: Electrical engineering; Electromagnetics; Beam Forming; Microstrip Antennas; Phased-Arrays; Reconfigurable Antennas; Tunable Antennas

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Avser, B. (2015). Frequency Tunable Antennas and Novel Phased Array Feeding Networks for Next Generation Communication Systems. (Thesis). University of California – San Diego. Retrieved from http://www.escholarship.org/uc/item/6cq329s4

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Avser, Bilgehan. “Frequency Tunable Antennas and Novel Phased Array Feeding Networks for Next Generation Communication Systems.” 2015. Thesis, University of California – San Diego. Accessed April 18, 2021. http://www.escholarship.org/uc/item/6cq329s4.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Avser, Bilgehan. “Frequency Tunable Antennas and Novel Phased Array Feeding Networks for Next Generation Communication Systems.” 2015. Web. 18 Apr 2021.

Vancouver:

Avser B. Frequency Tunable Antennas and Novel Phased Array Feeding Networks for Next Generation Communication Systems. [Internet] [Thesis]. University of California – San Diego; 2015. [cited 2021 Apr 18]. Available from: http://www.escholarship.org/uc/item/6cq329s4.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Avser B. Frequency Tunable Antennas and Novel Phased Array Feeding Networks for Next Generation Communication Systems. [Thesis]. University of California – San Diego; 2015. Available from: http://www.escholarship.org/uc/item/6cq329s4

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

University of California – San Diego

27. Zihir, Samet. Single-Chip 64- and 256-Element Wafer-Scale Phased Arrays and Communication Circuits in Advanced SiGe and CMOS Technologies.

Degree: Electrical Engineering (Electronic Circuits and Systems), 2015, University of California – San Diego

URL: http://www.escholarship.org/uc/item/8xj0z7vt

► The development of millimeter-wave phased arrays has been mostly based on silicon RFIC chips containing 8-16 channels and connected to antennas on organic printed circuit… (more)

Subjects/Keywords: Electrical engineering; 5G; Millimeter-wave; Phased arrays; RFIC; Sige BiCMOS; Wafer-scale

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Zihir, S. (2015). Single-Chip 64- and 256-Element Wafer-Scale Phased Arrays and Communication Circuits in Advanced SiGe and CMOS Technologies. (Thesis). University of California – San Diego. Retrieved from http://www.escholarship.org/uc/item/8xj0z7vt

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Zihir, Samet. “Single-Chip 64- and 256-Element Wafer-Scale Phased Arrays and Communication Circuits in Advanced SiGe and CMOS Technologies.” 2015. Thesis, University of California – San Diego. Accessed April 18, 2021. http://www.escholarship.org/uc/item/8xj0z7vt.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Zihir, Samet. “Single-Chip 64- and 256-Element Wafer-Scale Phased Arrays and Communication Circuits in Advanced SiGe and CMOS Technologies.” 2015. Web. 18 Apr 2021.

Vancouver:

Zihir S. Single-Chip 64- and 256-Element Wafer-Scale Phased Arrays and Communication Circuits in Advanced SiGe and CMOS Technologies. [Internet] [Thesis]. University of California – San Diego; 2015. [cited 2021 Apr 18]. Available from: http://www.escholarship.org/uc/item/8xj0z7vt.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Zihir S. Single-Chip 64- and 256-Element Wafer-Scale Phased Arrays and Communication Circuits in Advanced SiGe and CMOS Technologies. [Thesis]. University of California – San Diego; 2015. Available from: http://www.escholarship.org/uc/item/8xj0z7vt

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

University of Michigan

28. Flynn, Tyler. Remote Acoustic Sensing of Vibrating Structures for Structural Health Monitoring.

Degree: PhD, Mechanical Engineering, 2019, University of Michigan

URL: http://hdl.handle.net/2027.42/151467

► Acoustic radiation from a vibrating mechanical structure subject to narrow or broadband forcing is inherently dependent on the structure’s condition, material, geometry, and boundary conditions.… (more)

▼ Acoustic radiation from a vibrating mechanical structure subject to narrow or broadband forcing is inherently dependent on the structure’s condition, material, geometry, and boundary conditions. In many applications – such as those in naval, automotive, and civil engineering – acoustic recordings of a structure of interest may be easily and affordably obtained using a remote passive receiver or an array of receivers. As a result, there is great value in structural health monitoring techniques that can yield insight into a structure’s condition using such conveniently accessible data sets, even though these methods bring forth the added complexity of acoustic propagation in the environment, source-receiver geometry, exogenous acoustic sources, etc. This dissertation details the development and evaluation of remote acoustic sensing techniques for the detection, localization, and classification of damage and/or mechanical changes in a vibrating structure. These methods are based on comparisons of current test recordings with known baseline measurements in concert with both conventional and advanced array signal processing methods to achieve accurate and robust remote sensing performance. Results are divided primarily into three sections reflecting the three classical components of structural health monitoring: Detection, Localization, and Classification of damage or changes. An experimental apparatus was constructed for base excitation of 30 cm square plates, wherein various forms of mechanical changes (i.e. synthetic damage) were applied to plates of differing material properties and geometry in order to test and evaluate the proposed methods. Detection of synthesized damage including cuts, fastener faults, delamination, and localized added mass are achieved via baseline comparisons of remote array recordings of the plates’ acoustic signatures. Cuts in metal plates as small as 1.3 cm and delamination areas of 6 cm2 in composite fiber plates are detectable with >99% certainty using remote acoustic measurements captured meters from the plates. The addition of a blind deconvolution algorithm is shown to improve robustness of the method in practical environments with considerable unknown reverberation, for signal-to-reverberation ratios as low as -13 dB. A method for localization of mechanical changes/damage is presented using an innovative array-based coherent background subtraction technique that combines an existing high-resolution beamforming method with an additional subarray averaging step, ultimately enabling localization of small changes from a distributed acoustic source. Results are presented for the localization of cuts, fastener faults, and delamination in non-compact vibrating plates. Finally, a data-driven method is presented for the classification of cuts, fastener faults, and corrosion in vibrating plates via remote acoustic recordings. Using Monte Carlo finite element simulated training data for various damage cases, several classification strategies are evaluated and compared. Damage classification rates… Advisors/Committee Members: Dowling, David R (committee member), Vlahopoulos, Nickolas (committee member), Popa, Bogdan Ioan (committee member), Tol, Serife (committee member), Wang, Kon-Well (committee member).

Subjects/Keywords: acoustics; phased arrays; signal processing; vibration; remote sensing; structural health monitoring; Mechanical Engineering; Engineering

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Flynn, T. (2019). Remote Acoustic Sensing of Vibrating Structures for Structural Health Monitoring. (Doctoral Dissertation). University of Michigan. Retrieved from http://hdl.handle.net/2027.42/151467

Chicago Manual of Style (16^th Edition):

Flynn, Tyler. “Remote Acoustic Sensing of Vibrating Structures for Structural Health Monitoring.” 2019. Doctoral Dissertation, University of Michigan. Accessed April 18, 2021. http://hdl.handle.net/2027.42/151467.

MLA Handbook (7^th Edition):

Flynn, Tyler. “Remote Acoustic Sensing of Vibrating Structures for Structural Health Monitoring.” 2019. Web. 18 Apr 2021.

Vancouver:

Flynn T. Remote Acoustic Sensing of Vibrating Structures for Structural Health Monitoring. [Internet] [Doctoral dissertation]. University of Michigan; 2019. [cited 2021 Apr 18]. Available from: http://hdl.handle.net/2027.42/151467.

Council of Science Editors:

Flynn T. Remote Acoustic Sensing of Vibrating Structures for Structural Health Monitoring. [Doctoral Dissertation]. University of Michigan; 2019. Available from: http://hdl.handle.net/2027.42/151467

29. Mandeville, Andrew R. An Orthogonally-Fed, Active Linear Phased Array of Tapered Slot Antennas.

Degree: MS, Electrical & Computer Engineering, 2008, University of Massachusetts

URL: https://scholarworks.umass.edu/theses/114

► An active, broadband antenna module amenable for use in low cost phased arrays is proposed. The module consists of a Vivaldi antenna integrated with a… (more)

Subjects/Keywords: active arrays; active antennas; low-cost phased arrays; tapered slot antennas; Vivaldi antennas; wideband phased arrays

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APA (6^th Edition):

Mandeville, A. R. (2008). An Orthogonally-Fed, Active Linear Phased Array of Tapered Slot Antennas. (Masters Thesis). University of Massachusetts. Retrieved from https://scholarworks.umass.edu/theses/114

Chicago Manual of Style (16^th Edition):

Mandeville, Andrew R. “An Orthogonally-Fed, Active Linear Phased Array of Tapered Slot Antennas.” 2008. Masters Thesis, University of Massachusetts. Accessed April 18, 2021. https://scholarworks.umass.edu/theses/114.

MLA Handbook (7^th Edition):

Mandeville, Andrew R. “An Orthogonally-Fed, Active Linear Phased Array of Tapered Slot Antennas.” 2008. Web. 18 Apr 2021.

Vancouver:

Mandeville AR. An Orthogonally-Fed, Active Linear Phased Array of Tapered Slot Antennas. [Internet] [Masters thesis]. University of Massachusetts; 2008. [cited 2021 Apr 18]. Available from: https://scholarworks.umass.edu/theses/114.

Council of Science Editors:

Mandeville AR. An Orthogonally-Fed, Active Linear Phased Array of Tapered Slot Antennas. [Masters Thesis]. University of Massachusetts; 2008. Available from: https://scholarworks.umass.edu/theses/114

University of California – Irvine

30. Adas, Enver. Mode-Free Radiating Electromagnetic Bandgap Materials and Their Applications to Microstrip Phased Arrays.

Degree: Electrical and Computer Engineering, 2016, University of California – Irvine

URL: http://www.escholarship.org/uc/item/9nc746wn

► In addition to radiation, microstrip phased arrays excite substrate waves. These substrate waves are not desired since they keep energy, in the substrate, that is… (more)

▼ In addition to radiation, microstrip phased arrays excite substrate waves. These substrate waves are not desired since they keep energy, in the substrate, that is supposed to be radiated. Thus, array elements couple to each other through the substrate waves, and eventually radiation performance of the array degrades. Depending on the elements' excitation phase, or along certain radiation directions, almost all of the power at the array input couples to the substrate waves and radiating array fails to function as a radiator, instead it behaves as a guiding structure; this phenomenon is known as scan blindness, and it must be solved for an array to function properly. Electromagnetic bandgap (EBG) materials are engineered composite materials and capable to forbid wave propagation at frequencies within their bandgap. This thesis is focused on the integration of EBG materials and microstrip phased arrays. To be more specific, a multifunctional structure, which can be considered as a bandgap material, an antenna element, or a phased array consisted of the elements of the proposed structure, has been designed, fabricated, and measured. Numerical eigenmode and two port transmission methods are used for the bandgap investigation. Radiation properties of the structure has been improved using an impedance matching network. Scan analyses of both infinite and finite arrays have been studied. A prototype of 3 elements linear phased array of the proposed multifunctional structure has been fabricated and its active element pattern has been measured.The proposed multifunctional bandgap-antenna structure suppresses both bound and radiating substrate waves. Therefore, it provides complete elimination of scan blindness along all directions. In addition, unit element of the multifunctional structure has similar radiation characteristics, such as radiation pattern, gain, and polarization, as a conventional microstrip antenna; whereas, its scan behavior is the key achievement over the conventional microstrip arrays. Different from conventional arrays, this structure does not support any mode propagating along the lateral directions in the array structure; therefore, power entering to the array structure will radiate to free space.

Subjects/Keywords: Electrical engineering; Electromagnetics; Electromagnetic Bandgap; leaky waves; microstrip phased arrays; mode-free; scan blindness; Surface waves

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Adas, E. (2016). Mode-Free Radiating Electromagnetic Bandgap Materials and Their Applications to Microstrip Phased Arrays. (Thesis). University of California – Irvine. Retrieved from http://www.escholarship.org/uc/item/9nc746wn

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Adas, Enver. “Mode-Free Radiating Electromagnetic Bandgap Materials and Their Applications to Microstrip Phased Arrays.” 2016. Thesis, University of California – Irvine. Accessed April 18, 2021. http://www.escholarship.org/uc/item/9nc746wn.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Adas, Enver. “Mode-Free Radiating Electromagnetic Bandgap Materials and Their Applications to Microstrip Phased Arrays.” 2016. Web. 18 Apr 2021.

Vancouver:

Adas E. Mode-Free Radiating Electromagnetic Bandgap Materials and Their Applications to Microstrip Phased Arrays. [Internet] [Thesis]. University of California – Irvine; 2016. [cited 2021 Apr 18]. Available from: http://www.escholarship.org/uc/item/9nc746wn.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Adas E. Mode-Free Radiating Electromagnetic Bandgap Materials and Their Applications to Microstrip Phased Arrays. [Thesis]. University of California – Irvine; 2016. Available from: http://www.escholarship.org/uc/item/9nc746wn

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Open Access Theses and Dissertations