Title:  Design and Integration of Hybrid and Monolithic Microwave Power Amplifiers for Wideband Applications using Gallium Nitride Technology

Committee: 

Dr. Papapolymerou, Advisor 

Dr. Cressler, Chair

Dr. Wang

Dr. Gebara

Abstract: The objective of the proposed research is to compare, contrast, and  advance the predominant methods of realizing broadband microwave power  amplifiers (PAs) up to 40 GHz with high efficiency using gallium nitride  (GaN) technology. The studied architectures are based on the  reactive/resistive matching approach and the traveling wave technique in  both hybrid and monolithic microwave integrated circuits (MMICs). With a  focus on improving the bandwidth and efficiency of these architectures,  the presented hybrid PA designs achieve cutting edge performance from  commercially available GaN power transistors. Further details of design  development and integration are discussed, featuring discrete component  descriptions, substrate material selections, additional matching  techniques, and analyses of both wirebonds and flip-chip bonds that are  used for PA interconnections. To complement these novel hybrid PA design  and integration developments, the results of device characterization and  wideband modeling are presented for a new 0.15 µm GaN MMIC process in  support of a broadband PA design with reactive/resistive matching.  Finally, an ultra-wideband MMIC non-uniform distributed PA design is  fabricated on a pre-release version of a new 0.14 µm GaN MMIC process,  and preliminary small-signal measurements from 2-40 GHz show promising  results.