Large signal design method of distributed power amplifiers applied to a 2–18-GHz GaAs chip exhibiting high power density performances

Abstract

A suitable large signal design method of distributed power amplifiers, based on the optimum FET load requirement for high power operation, is proposed in this article. The gate and drain line characteristic admittances are determined, providing both the initial values and right directions for an optimum design. To validate the proposed design method, a FET amplifier demonstrator with a gate periphery of 1.2 mm has been manufactured at the Texas Instruments foundry. The MMIC distributed amplifier demonstrated an improved power density performance of 340 mW/mm over the 2–18‐GHz frequency band associated with a minimum of 13% power‐added efficiency and 24% drain efficiency at 1‐dB compression in CW operation. © 1996 John Wiley & Sons, Inc.

Two Octave Phemt Power Amplifier for EW Applications

“…But, conventional distributed amplifiers based on small signal design are not suitable for maximum power operation. The 1 W amplifier presented in this paper has been designed using a methodology based on a large signal approach [1,2]. This methodology is based on a specific tapering of gate and drain lines omitting the drain load to optimise power operation.…”

“…Criteria like maximum power and maximum efficiency, but also high reliability and high integration, are some of the most important issues. In this context, MESFET technology has shown some good results [1], but is still limited in efficiency and gain at high frequencies. HBT technology has demonstrated the best results in power density and some good results in achieving wide band performance [2,3].…”

Design considerations for the dual-fed distributed power amplifier

“…Over some frequency ranges, some of the FETs sink rather than source power [1]. Methods such as output line tapering [2] may be used to minimise power in the backward waves and circuit optimisation [3] may be used to improve the output power distribution among the FETs. However, their success is limited as the problems they aim to cure are fundamental in nature.…”

2-6 GHz GaN distributed power amplifier MMIC with tapered gate-series/drain-shunt capacitors

“…However, nonuniform distributed matching is disadvantageous in that it requires complicated optimization to obtain a phase balance between the input and output artificial transmission lines. Conventional uniform distributed matching causes difficulties when it is used in designing the power amplifier because the uniform distributed lines provide each transistor with different and nonoptimal load impedances, and transistors near the load termination do not operate properly [14].…”