Abstract
This dissertation shows that filter synthesis techniques can be used to design and enhance the performance of several discrete components of the RF front-end. Throughout this work, a block diagram of a typical receiver is used to illustrate each component separately. Four main areas are covered: (1) filter/antenna integration, (2) frequency-tunable filter/antenna integration with control of the bandwidth characteristics, (3) antenna arrays designed based on integrated cavity resonators, and (4) novel low-loss phase shifters using band-pass and band-stop filters. The filter/antenna designed using two cavity resonators with a slot antenna in the second cavity. The slot antenna excites two modes in the slot cavity, creating a third-order filtering response while preserving the radiating characteristics. A transmission zero can be arbitrarily placed below or above the passband. Tunable integrated filter/antennas are demonstrated with two coupling configurations that provide design control of the bandwidth performance over the tuning range. The first is a single-layer third-order tunable filter/antenna with increasing fractional bandwidth. The second is a double-layer vertically-integrated third-order tunable filter/antenna that provides constant absolute bandwidth over the tuning range. This design accounts for the frequency-dependent behavior of the antenna radiation Q. The filtering array is designed in substrate integrated waveguide technology and consists of 5 coupled cavities with a 6th-order filtering function. The antenna array is formed with a linear arrangement of four slot antennas in the final cavities which excite two modes in the radiating cavity. A new class of phase shifter based on a bandpass filter with reconfigurable transmission zeros is presented in this work. By using tunable resonators that are extracted from the main signal path, a transmission phase shift is obtained with minimal effect on the insertion loss from the tuning elements. The culmination of this work is a continuously tunable phase shifter designed based on a band-stop filter. A full 360-degree phase range can be continuously tuned while keeping the insertion loss below 2 dB and this is confirmed by designing a beamforming antenna array based on these phase shifters.
Notes
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Graduation Date
2021
Semester
Spring
Advisor
Gong, Xun
Degree
Doctor of Philosophy (Ph.D.)
College
College of Engineering and Computer Science
Department
Electrical and Computer Engineering
Degree Program
Electrical Engineering
Format
application/pdf
Identifier
CFE0008494; DP0024170
URL
https://purls.library.ucf.edu/go/DP0024170
Language
English
Release Date
5-15-2021
Length of Campus-only Access
None
Access Status
Doctoral Dissertation (Open Access)
STARS Citation
Lovato, Ricardo, "Performance Enhancement of RF/Microwave Devices Using Filter Synthesis Techniques" (2021). Electronic Theses and Dissertations, 2020-2023. 523.
https://stars.library.ucf.edu/etd2020/523