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You searched for subject:(fundamental resonant frequency). Showing records 1 – 2 of 2 total matches.

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University of New Mexico

1. Lawrance, Julie E. The Fundamental Resonant Frequency and Radiation Characteristics of Wide Angle Conical Antennas.

Degree: Electrical and Computer Engineering, 2011, University of New Mexico

Of recent interest for simple compact pulse power systems is the self-resonant wide-angle conical antenna. In its typical application, this antenna will radiate a transient damped sine wave pulse whose center frequency is the fundamental resonant frequency of the antenna. In order to properly design such an antenna, it is important to know the dependence of the fundamental resonant frequency on both slant height and half cone angle. Theoretical analysis of this type of antenna is typically based on the mode theory of antennas (as derived by S.A. Schelkunoff) in which the structure is treated as a conical transmission line. The theory is quite complicated and leads to two sets of equations involving infinite sums which must be solved simultaneously; this is a difficult task. In this effort, the accuracy of simplifications to the theory in predicting the fundamental resonant frequency of a wide angle conical antenna was explored by comparing the results obtained based on these approximations to experimental results as well as the results of numerical simulation using CST Microwave Studio. Good agreement is obtained between the simulated and experimentally measured results. It was found that a first order approximation to the theory as derived by C. Papas and R. King, while otherwise very useful, is insufficient to predict the fundamental resonant frequency of a wide angle conical antenna with reasonable accuracy; however, a second order approximation as derived by P.D.P. Smith does yield results that are in good agreement with results of experiment and simulation. It was found that the relationship between slant height (\u2113) and wavelength (λ) at the fundamental resonant frequency, for wide half cone angles, corresponds more closely to \u2113= λ /8 than the expected \u2113= λ /4. Of primary interest was the fundamental resonant frequency as a function of slant height and half cone angle; however, the peak radiated electric field and the radiation efficiency of the conical antenna as a function of half cone angle was also explored. Advisors/Committee Members: Christodoulou, Christos, Christodoulou, Christos, Baum, Carl E., Schamiloglu, Edl.

Subjects/Keywords: wide angle conical antennas; fundamental resonant frequency

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

APA (6th Edition):

Lawrance, J. E. (2011). The Fundamental Resonant Frequency and Radiation Characteristics of Wide Angle Conical Antennas. (Masters Thesis). University of New Mexico. Retrieved from http://hdl.handle.net/1928/12048

Chicago Manual of Style (16th Edition):

Lawrance, Julie E. “The Fundamental Resonant Frequency and Radiation Characteristics of Wide Angle Conical Antennas.” 2011. Masters Thesis, University of New Mexico. Accessed June 20, 2019. http://hdl.handle.net/1928/12048.

MLA Handbook (7th Edition):

Lawrance, Julie E. “The Fundamental Resonant Frequency and Radiation Characteristics of Wide Angle Conical Antennas.” 2011. Web. 20 Jun 2019.

Vancouver:

Lawrance JE. The Fundamental Resonant Frequency and Radiation Characteristics of Wide Angle Conical Antennas. [Internet] [Masters thesis]. University of New Mexico; 2011. [cited 2019 Jun 20]. Available from: http://hdl.handle.net/1928/12048.

Council of Science Editors:

Lawrance JE. The Fundamental Resonant Frequency and Radiation Characteristics of Wide Angle Conical Antennas. [Masters Thesis]. University of New Mexico; 2011. Available from: http://hdl.handle.net/1928/12048


Universitat Politècnica de València

2. García Narbón, José Vicente. Improved characterization systems for quartz crystal microbalance sensors: parallel capacitance compensation for variable damping conditions and integrated platform for high frequency sensors in high resolution applications .

Degree: 2016, Universitat Politècnica de València

[EN] Different electronic interfaces have been proposed to measure major parameters for the characterization of quartz crystal microbalance (QCM) during the last two decades. The measurement of the adequate parameters of the sensor for a specific application is very important, since an error in this measure can lead to an error in the interpretation of the results. The requirements of the system of characterization depend on the application. In this thesis we propose two characterization systems for two types of applications that involve the majority of sensor applications: 1) Characterization of materials under variable damping conditions and 2) Detection of substances with high measurement resolution. The proposed systems seek to solve the problems detected in the systems currently in use. For applications in which the sensor damping varies during the experiment, we propose a system based on a new configuration of the technique of automatic capacitance compensation (ACC). This new configuration provides the measure of the series resonance frequency, the motional resistance and the parallel capacitance of the sensor. Moreover, it allows an easy calibration of the system that improves the precision in the measurement. We show the experimental results for 9 and 10 MHz crystals in fluid media, with different capacitances in parallel, showing the effectiveness in the capacitance compensation. The system presents some deviation in frequency with respect to the series resonance frequency, as measured with an impedance analyser. These deviations are due to the non-ideal, specific behaviour of some of the components of the circuit. A new circuit is proposed as a possible solution to this problem. For high-resolution applications we propose an integrated platform to characterize high-frequency acoustic sensors. The proposed system is based on a new concept in which the sensor is interrogated by means of a very stable, low-noise external source at a constant frequency, while the changes provoked by the charge in the phase of the sensor are monitored. The use of high-frequency sensors enhances the sensitivity of the measure, whereas the design characterization system reduces the noise in the measurement. The result is an improvement in the limit of detection (LOD). This way, we achieve one of the challenges in the acoustic high-frequency devices. The validation of the platform is performed by means of an immunosensor based in high fundamental frequency QCM crystals (HFF-QCM) for the detection of two pesticides: carbaryl and thiabendazole. The results obtained for carbaryl are compared to the results obtained by another high-frequency acoustic technology based in Love sensors, with the optical technique based in surface plasmonic resonance and with the gold standard technique Enzyme Linked Immunoassay (ELISA). The LOD obtained with the acoustic sensors HFF-QCM and Love is similar to the one obtained with ELISA and improves by one order of magnitude the LOD obtained with SPR. The conceptual ease of the proposed system, its… Advisors/Committee Members: Jiménez Jiménez, Yolanda (advisor).

Subjects/Keywords: Capacitance compensation; Quartz microbalance; Oscillators; Series resonant frequency; Interface circuit; Acoustic wave sensor; Biosensor; Immunosensor; Carbaryl; Pesticide; QCM; SAW; Love wave; High Fundamental Frequency; HFF QCM

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

APA (6th Edition):

García Narbón, J. V. (2016). Improved characterization systems for quartz crystal microbalance sensors: parallel capacitance compensation for variable damping conditions and integrated platform for high frequency sensors in high resolution applications . (Doctoral Dissertation). Universitat Politècnica de València. Retrieved from http://hdl.handle.net/10251/63249

Chicago Manual of Style (16th Edition):

García Narbón, José Vicente. “Improved characterization systems for quartz crystal microbalance sensors: parallel capacitance compensation for variable damping conditions and integrated platform for high frequency sensors in high resolution applications .” 2016. Doctoral Dissertation, Universitat Politècnica de València. Accessed June 20, 2019. http://hdl.handle.net/10251/63249.

MLA Handbook (7th Edition):

García Narbón, José Vicente. “Improved characterization systems for quartz crystal microbalance sensors: parallel capacitance compensation for variable damping conditions and integrated platform for high frequency sensors in high resolution applications .” 2016. Web. 20 Jun 2019.

Vancouver:

García Narbón JV. Improved characterization systems for quartz crystal microbalance sensors: parallel capacitance compensation for variable damping conditions and integrated platform for high frequency sensors in high resolution applications . [Internet] [Doctoral dissertation]. Universitat Politècnica de València; 2016. [cited 2019 Jun 20]. Available from: http://hdl.handle.net/10251/63249.

Council of Science Editors:

García Narbón JV. Improved characterization systems for quartz crystal microbalance sensors: parallel capacitance compensation for variable damping conditions and integrated platform for high frequency sensors in high resolution applications . [Doctoral Dissertation]. Universitat Politècnica de València; 2016. Available from: http://hdl.handle.net/10251/63249

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