Broadband class-E power amplifier design using tunable output matching network

Abstract

This paper presents a design of a broadband high-efficiency Class-E power amplifier (PA) with a tunable output matching network (OMN). The OMN contains two main parts: The first part is a Tunable Band-Pass Filter (T-BPF) that determines the center frequency of the PA’s operational bandwidth. And the first part is a fixed matching network that transforms the input impedance of the second part (50 Ω) to an optimum impedance value of transistor’s drain. The tuning process of the BPF is realized using a Varactor Diode Stack. By changing the bias voltage of the varactor diodes, the center frequency of T-BPF can move throughout 1–2.55 GHz bandwidth. The GaN HEMT CGH40010F from Cree has been selected due to its wide bandwidth, high efficiency, and high achievable gain for PA design. Simulation results show an output power of 40–41.5 dBm, Drain Efficiency (DE%) of 57.2–81.2% and transducer power gain of 10–12.5 dB across 1–2.55 GHz (87.3% fractional bandwidth). The proposed design outperforms previous tunable and fixed power amplifiers regarding bandwidth and efficiency.