A 10 watt class-AB pulse power amplifier

Abstract

In this article, simulation and implementation of a 10 watt class-AB pulse power amplifier using LDMOS transistor in 1.2-1.4 GHz is presented. Class-AB RF amplifier is commonly used in wireless communication industry because it offers an acceptable compromise between linearity and efficiency. Load pull and source pull software utilities are employed to obtain the optimum input and output impedances of the device. Afterwards, the input and the output matching networks based on a low pass Chebyshev filter were designed and optimized via computer aided simulation. The proposed design approach of matching networks enables improvements in both linearity and efficiency at 6 dB back off input power without the need for a linearizer. The power amplifier exhibits 40-41 dBm output power at 1 dB gain compression point (P1dB), 18 dB minimum signal gain and above 50% drain efficiency throughout the band. The measurement results show that the amplifier is very suitable for use in the driver stage of a very high power amplifier due to its high gain flatness.