Investigation of an Enhanced Efficiency Class-E Power Amplifier with Input Wave Shaping Network

Abstract

In this paper, investigation result of a Class-E power amplifier (PA), using a GaN HEMT, operating at 2 GHz frequency with 10W output power and better than 82% power added efficiency (PAE) is reported. The improvement in the efficiency of the PA has been achieved by the incorporation of an appropriate input matching network topology. This matching network transforms the impedance from source to the desired impedance for conjugate match in addition to suppressing the second harmonic component of the signal from reaching the gate of the GaN HEMT. In essence, the suppression of the second harmonic enables fundamental frequency signal and third harmonic signal to combine at the gate terminal. It leads to sharper rising/falling of signal for faster switching of the device and hence higher power efficiency.