High-efficiency switched-mode power amplifier using gallium nitride on silicon hemt technology

Abstract

The continuing trend toward greater capacity and higher d a ta rates in wireless commu nication systems places increasing dem ands on the radio frequency (RF) power provided by base station transm itters. Conventional R F power amplifiers (PAs) in use today have poor operating efficiencies and require considerable additional power and volume for heat removal. Research on more efficient PA technology is therefore im portant to the growth of the wireless industry. This thesis investigates high-efficiency switched-mode microwave power amplification using a new transistor technology, the Gallium N itride on Silicon High Electron Mobility Transistor (GaN-on-Si HEM T), which promises to deliver high o u tp u t power levels at lower cost th an the alternative GaN-on-SiC technology. The principles of power devices and power amplification modes axe discussed. A new large-signal equivalent model is developed for a 2 mm GaN-on-Si HEM T over the 0 GHz -20 GHz range, based on measured data. The chosen EEsof GaAs nonlinear HEM T model reproduces th e GaN transistor's behavior reasonably well over a large range of bias conditions, signal levels, and frequencies, although several param eter assum ptions are made. Based on this model, the design, optim ization, fabrication and testing of a 3.5 GHz, 1 W, Class E power ii Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.amplifier proceeds. The PA design is successful, w ith measurements revealing a gain of 10.7 dB, w ith an output power of 942 mW , and a power-added efficiency of 40.4%.This work shows the suitability of lower cost GaN-on-Si transistor technology for switched-mode microwave power amplifiers w ith possible applications in W iMAX base stations. It is recommended th a t further device modeling and other switched-mode am plifier topologies be investigated.iii Reproduced with

Using LDMOS Transistor in Class-F Power Amplifier For WCDMA Applications

“…A WCDMA system with QPSK modulation is employed in UMTS, where both phase and amplitude variations are established by the modulation. The power amplifiers which are designed for WCDMA should suit the contradicting operation requirement between linearity and efficiency [1,2]. A very efficient class F power amplifier which has been designed for WCDMA band with a center frequency of 2.14 GHz and bandwidth of 5 MHz, applying LDMOS transistor, is introduced in this paper.…”

GaN HFET modeling and model validation through high efficiency power amplifier design

“…Existing work performed by other researchers at Carleton University within the department of electronics that relate closely to this topic include [14] [15]. In [14],…”

“…Chyurlia presents a feasibility analysis of the integration of AlGaN HFETs with CMOS on silicon substrates. In [15] Panesar designs a class-E switch mode power amplifier using a 2 mm transistor from the same die that the 100 /xm transistor for this work came from. The key difference between those two theses and this work is that this thesis is primarily an exercise in modelling that uses class-F PA design as a method of validating the model that was created.…”