A Systematic Design of 1.5-9 GHz High Power-High Efficiency Two-Stage GaAs PHEMT Power Amplifier

In this article, a systematic design approach for a Class-A operated wideband power amplifier is presented. The power amplifier structure comprises of two transistors in the cascaded single stage traveling wave amplifier topology. A power amplifier was designed by using the systematic approach and fabricated with 0.25 m GaAs PHEMT MMIC process. The amplifier has an area of 3.4 x 1.4 mm(2). Measurement results show that almost flat gain performance is obtained around 15 dB over 1.5-9 GHz operating bandwidth. In most of the band, with the help of a wideband load-pull matching technique, the amplifier delivers P-o,P-sat and P-o,P-1dB of around 30 dBm and 28 dBm where the corresponding power added efficiencies are >50% and >36%, respectively. It is shown that the proposed design approach has the advantage of simple and systematic design flow and it helps to realize step-by-step design for the designers. (c) 2014 Wiley Periodicals, Inc. Int J RF and Microwave CAE 24:615-622, 2014.