Ozan Gurbuz Final Defense

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Event Date: 
Friday, November 6, 2015
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2:00pm-4:00pm Jacobs Hall 4309

CWC Advisor: Prof. Gabriel Rebeiz

High-efficiency On-chip Antennas at mm-Wave Frequencies and Tunable Circuits for Cellular Communications 

Millimeter wave frequencies have gained importance as microwave frequency bands got more crowded and advancements in the technology allowed development of systems at millimeter waves. They are designed and in the process of development for a wide range of applications such as 5G, security systems and high data-rate communication systems.

First part of this dissertation focuses on high-efficiency on-chip antennas at 375 GHz for THz signal generation, 360 GHz for passive imaging arrays and 160GHz for radiometry.

Advancements in the cellular communications require the use of many different bands in a wide frequency range. Tunable RF circuits have gained importance with their potential to replace switched RF systems with the performance advancements of the tuning devices over the years.

Second of this dissertation focuses on two different tunable circuits intended to be used in future cellular communication systems in micro and pico base stations. First one is a reconfigurable phase shifter working in 1.6-2.2 GHz range built using RF MEMS digitally variable capacitors (DVC) with high linearity and high power handling. Phase shifter is based on a tunable quadrature coupler where the design of the coupler is provided in detail too. Second one is a tunable notch filter working in 1.8-2.0 GHz range built using RF MEMS DVC's. Notch filters are used for blocking the strong interferers to prevent desensitization of receiver chains so the filters should be highly linear and should be able to handle high power levels which are notable characteristics of RF MEMS technology. The design procedure to get high performance filters is provided.