Improved inverse class-E matching network for microwave high power amplifiers

This paper presets a 8.5 W GaN inverse class-E power amplifier using an output matching network suitable for high power applications. The presented output matching network overcomes several problems in the original implementation. First a transmission line stub is used directly at the transistor drain to compensate for the drain source capacitance, second the lumped inductor in the original implementation is replaced by a short transmission line, which makes it suitable for high power amplifiers. The designed GaN inverse class-E amplifier achieves a maximum drain efficiency of 77% with output power of 39 dBm at a drain supply voltage of 35 V. Additionally through varying the supply voltage the presented amplifier gives a drain efficiency greater than 70% over an 8 dB dynamic range.