Exploring the Design Flexibility of the Class-E Power Amplifier with Shunt Capacitance and Shunt Filter

The Class-E power amplifier (PA) with shunt capacitance and shunt filter offers a unique design flexibility which can be exploited either to extend the maximum operating frequency of the PA or to allow the use of large active devices with high power handling capability. In this paper, a novel transmission-line load network is proposed to provide the drain of the active device with the required load impedances at the fundamental frequency as well as at even and odd harmonic frequencies. The concept is verified through simulations and measurements of a circuit prototype, which delivers a peak drain efficiency of 90.2%, a peak power-added efficiency of 82.7%, and a peak output power of 39.8 dBm at 1.37 GHz.