Title:  High Efficiency Broadband Power Amplifier using SiGe HBT BiCMOS Technology

Committee: 

Dr. Cressler, Advisor     

Dr. Ayazi, Chair

Dr. Shaolan Li

Abstract: The objective of the proposed research is to investigate the design challenges of high-efficiency broadband power amplifiers (PAs) using silicon germanium (SiGe) heterojunction bipolar transistors (HBTs) and develop multiple design methodologies to address these challenges. Wideband amplification is crucial for emerging wireless broadband applications such as phased array radars, high resolution imaging, secured military/satellite communications, and the fifth-generation new radio standard. To support the system level requirements for low cost and high integration capability, a silicon-based (Si-based) broadband PA can be a viable solution. To overcome poor power added efficiency (PAE) and low output power of a uniform distributed amplifier, an emphasis of this research is placed on Si-based non-uniform distributed power amplifier (NDPA), which achieves optimum power matching by simultaneously scaling each active device size and the characteristic impedance (Z0) of the output transmission line (TL) segment. The main design challenge of Si-based NDPAs is the implementation of high Z0 output TL over wide BW. To address the challenges, the preliminary research suggests two approaches: 1) multi-section lumped-element TLs for a millimeter-wave (mm-wave) SiGe HBT NDPA, 2) a novel, compact, wideband two-section lumped-element output impedance transformer to lower the output load impedance for a 2‒24 GHz SiGe HBT NDPA. The proposed research will establish a systematic design methodology of Si-based highly efficient NDPA based on thorough analysis on the preliminary research and include the development of a watt-level high-efficiency broadband SiGe HBT PA for power backoff PAE enhancement.