Studies on quasi-optical devices /
This dissertation examines three types of quasi-optical devices. A unique low-loss coupling technique for the Fabry-Perot resonator has been developed. The technique couples dominant waveguide modes to higher-order modes of the resonator. A thorough literature review of coupling techniques substa...
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| Format: | Thesis Book |
| Language: | English |
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[Place of publication not identified] :
[publisher not identified] ;
1996.
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| Subjects: | |
| Online Access: | http://proxy.library.tamu.edu/login?url=http://proquest.umi.com/pqdweb?did=739363581&sid=1&Fmt=2&clientId=2945&RQT=309&VName=PQD |
| Summary: | This dissertation examines three types of quasi-optical devices. A unique low-loss coupling technique for the Fabry-Perot resonator has been developed. The technique couples dominant waveguide modes to higher-order modes of the resonator. A thorough literature review of coupling techniques substantiates the uniqueness of the technique. The efficiency of the coupling is demonstrated by measurements of slot-fed higher-order mode filters. The TEM300 and TEM400 modes of a resonator with circular mirrors are mechanically tunable with insertion losses less than 1 dB over a 20% bandwidth at X-band and over a 25% bandwidth at Ka-band. The filters have unloaded Q values up to 7000 at X-band and 3000 at Ka-band. A method of analyzing the performance of rectennas (rectifying antennas) has been developed based on experimental data for the efficiency of single rectenna elements. The method takes into account the local variation of power density on the rectenna. The analysis predicts the output power of the rectenna from a 1975 wireless power transmission demonstration within 6.4% of the measured values. Optimization algorithms for maximizing the efficiency and output power of a rectenna are presented. The rectenna model is incorporated in a simulation of wireless power transmission systems. An analysis is developed to predict the transmission through a strip grid frequency selective surface (FSS) when the polarization of the incident wave is neither parallel nor perpendicular to the strips. The analysis is based on equivalent circuits for parallel and perpendicular incidence on the grid. Transmission measurements as a function of the angle that the incident polarization makes with the strips for a strip grid on a dielectric substrate at Ka-band show that the analysis is qualitatively good. The analysis is applicable to other FSS structures that have equivalent circuits and consist of straight strips oriented in two orthogonal directions. |
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| Item Description: | Vita. "Major Subject: Electrical Engineering". |
| Physical Description: | xviii, 166 leaves : illustrations ; 28 cm. Issued also on microfiche from University Microfilms Inc. |
| Bibliography: | Includes bibliographical references: pages 142-148. |