Design of a 200 Watt single-ended wideband gallium nitride-high electron mobility transistor power amplifier for wideband code division multiple access basestations

• Main Author: Andres, Pierreangelo Philamer
• Format: text
• Language: English
• Published: Animo Repository 2009
• Subjects: Transistor amplifiers; Power amplifiers; Gallium nitride; High-electron-mobility transistors; Modulation-doped field-effect transistors; Other Engineering
• Online Access: https://animorepository.dlsu.edu.ph/etd_masteral/3755; https://animorepository.dlsu.edu.ph/context/etd_masteral/article/10593/viewcontent/CDTG004542_P.pdf
• Institution: De La Salle University

Recent studies show that power amplifiers based on gallium nitride (GaN) high electron mobility transistors (HEMT) technology achieve higher power density compared to Silicon and GaAs field effect transistors (FET) due its wideband gap property and heterostructure. This results to higher power per transistor die size (W/mm), lower inherent parasitic components and thus broadband performance. This document describes the design and implementation of a 200W single ended Class AB broadband amplifier module operating from 2GHz to 2.2 GHz. With an IS95 test signal, the measured backoff gain and drain efficiency across the band is at 13.8dB and 28% respectively. Gain flatness is +/- 0.5 dB. The high source and load impedances at the package leads were achieved at the package leads with the optimized package design. Three broadband package topologies were studied and compared. Simulations suggest that package output bandwidth can be significantly improved with the InShin topology. 6 A design flow is described which yielded a first time right design. A large signal equivalent package model was extracted by using small signal and large signal measurements. The impedance transformation of the package components and PCB design was optimized not to exceed the inherent Q of the FET to maximize bandwidth. Optimum impedances from load pull measurements were used to realize the application circuit.