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You searched for subject:(Fast Calibration Technique). Showing records 1 – 2 of 2 total matches.

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University of Oklahoma

1. Islam, Shajid. Probe-based, quasi-near-field phased array calibration.

Degree: PhD, 2020, University of Oklahoma

Phased array technology provides remarkable scanning flexibility and spatial search capability for the multifunction radar system, airborne radar system, and many other applications. Recent years have seen a noticeable surge towards low cost, small phased array antenna technology in a varied range of sectors due to its diverse applicability. However, lowering the cost exposed phased array antenna to various errors, among which excitation errors, such as incorrect phase and amplitude, is one of the major concerns. Excitation errors affect essential performance parameters such as side-lobe level, antenna gain, active impedance, and beam-forming quality. It is crucial to quantify and compensate for the errors associated with each antenna element's phase and amplitude to ensure the phased array antenna's desired performance. The process of this compensation is widely known as the calibration of a phased array. The diverse application and increased use of a low cost small phased array system make the front end calibration procedure very challenging. This challenge is two-fold. The calibration should be done accurately and quickly as possible. This dissertation focuses on developing a novel technique of phased array calibration using a fixed probe in the quasi-near-field of the antenna. The objective is to significantly reduce calibration time and associated cost without compromising the calibration quality for initial and in-situ calibration. After the development of a successful mathematical framework, a detailed simulation is conducted to analyze the system. The proposed technique was finally validated using an active electronically scanned array inside a custom-made compact range and near field range. Advisors/Committee Members: Fulton, Caleb (advisor), Yeary, Mark (committee member), Havlicek, Joseph (committee member), Sigmarsson, Hjalti (committee member), Chavez-Dominguez, Javier (committee member).

Subjects/Keywords: Phased Array Calibration; Fast Calibration Technique; Quasi-Near-Field; Mutual Coupling

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

APA (6th Edition):

Islam, S. (2020). Probe-based, quasi-near-field phased array calibration. (Doctoral Dissertation). University of Oklahoma. Retrieved from http://hdl.handle.net/11244/326668

Chicago Manual of Style (16th Edition):

Islam, Shajid. “Probe-based, quasi-near-field phased array calibration.” 2020. Doctoral Dissertation, University of Oklahoma. Accessed March 08, 2021. http://hdl.handle.net/11244/326668.

MLA Handbook (7th Edition):

Islam, Shajid. “Probe-based, quasi-near-field phased array calibration.” 2020. Web. 08 Mar 2021.

Vancouver:

Islam S. Probe-based, quasi-near-field phased array calibration. [Internet] [Doctoral dissertation]. University of Oklahoma; 2020. [cited 2021 Mar 08]. Available from: http://hdl.handle.net/11244/326668.

Council of Science Editors:

Islam S. Probe-based, quasi-near-field phased array calibration. [Doctoral Dissertation]. University of Oklahoma; 2020. Available from: http://hdl.handle.net/11244/326668


Georgia Tech

2. Wang, Zhonglu. Design of a Boron Neutron Capture Enhanced Fast Neutron Therapy Assembly.

Degree: PhD, Mechanical Engineering, 2006, Georgia Tech

A boron neutron capture enhanced fast neutron therapy assembly has been designed for the Fermilab Neutron Therapy Facility (NTF). This assembly uses a tungsten filter and collimator near the patient¡¯s head, with a graphite reflector surrounding the head to significantly increase the dose due to boron neutron capture reactions. The assembly was designed using Monte Carlo radiation transport code MCNP version 5 for a standard 20x20 cm2 treatment beam. The calculated boron dose enhancement at 5.7-cm depth in a water-filled head phantom in the assembly with a 5x5 cm2 collimation was 21.9% per 100-ppm B-10 for a 5.0-cm tungsten filter and 29.8% for an 8.5-cm tungsten filter. The corresponding dose rate for the 5.0-cm and 8.5-cm thick filters were 0.221 and 0.127 Gy/min, respectively. To validate the design calculations, a simplified BNCEFNT assembly was built using four lead bricks to form a 5x5 cm2 collimator. Five 1.0-cm thick 20x20 cm2 tungsten plates were used to obtain different filter thicknesses and graphite bricks/blocks were used to form a reflector. Measurements of the dose enhancement of the simplified assembly in a water-filled head phantom were performed using a pair of tissue-equivalent ion chambers. One of the ion chambers is loaded with 1000-ppm natural boron (184-ppm 10B) to measure dose due to boron neutron capture. The measured dose enhancement at 5.0-cm depth in the head phantom for the 5.0-cm thick tungsten filter is (16.6 ¡À 1.8)%, which agrees well with the MCNP simulation of the simplified BNCEFNT assembly, (16.4¡À 0.5)%. The error in the calculated dose enhancement only considers the statistical uncertainties. The total dose rate measured at 5.0-cm depth using the non-borated ion chamber is (0.765 ¡À 0.076) Gy/MU, about 61% of the fast neutron standard dose rate (1.255Gy/MU) at 5.0-cm depth for the standard 10x10 cm2 treatment beam. The increased doses to other organs due to the use of the BNCEFNT assembly were calculated using MCNP5 and a MIRD phantom. Advisors/Committee Members: Hertel, Nolan (Committee Chair), Howell, Rebecca (Committee Member), Karam, Ratib (Committee Member), Lee, Eva (Committee Member), Lennox, Arlene (Committee Member), Wang, C-K Chris (Committee Member).

Subjects/Keywords: Neutron spectrum; HPGe; Efficiency calibration; Activation foil technique; Monte Carlo method; Cancer Radiotherapy; Fast neutrons; Boron-neutron capture therapy

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

APA (6th Edition):

Wang, Z. (2006). Design of a Boron Neutron Capture Enhanced Fast Neutron Therapy Assembly. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/14100

Chicago Manual of Style (16th Edition):

Wang, Zhonglu. “Design of a Boron Neutron Capture Enhanced Fast Neutron Therapy Assembly.” 2006. Doctoral Dissertation, Georgia Tech. Accessed March 08, 2021. http://hdl.handle.net/1853/14100.

MLA Handbook (7th Edition):

Wang, Zhonglu. “Design of a Boron Neutron Capture Enhanced Fast Neutron Therapy Assembly.” 2006. Web. 08 Mar 2021.

Vancouver:

Wang Z. Design of a Boron Neutron Capture Enhanced Fast Neutron Therapy Assembly. [Internet] [Doctoral dissertation]. Georgia Tech; 2006. [cited 2021 Mar 08]. Available from: http://hdl.handle.net/1853/14100.

Council of Science Editors:

Wang Z. Design of a Boron Neutron Capture Enhanced Fast Neutron Therapy Assembly. [Doctoral Dissertation]. Georgia Tech; 2006. Available from: http://hdl.handle.net/1853/14100

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