Design of broadband high-gain GaN MMIC power amplifier based on reactive/resistive matching and feedback technique

Abstract

This paper presents a K-band two-stage power amplifier (PA) with a compact circuit size of 1.8×0.87mm². To guarantee broadband high-gain output performance, the optimal impedance domain and power cell are determined through load/source-pull simulation and K-point method, respectively. Reactive/resistive matching networks are carefully employed to reduce the equivalent gate capacitance, improve stability and compensate for the device’s negative gain roll-off slope. Meanwhile, combining with feedback technique adopted in driver stage, the entire operation bandwidth can be further extended. Under 12V pulse voltage supply, 37.4% of peak power-added efficiency (PAE) at 26GHz and 24±0.5dB of small-signal gain, 30.3-31.6dBm of saturated output power (P_sat) across 22-27GHz are obtained as shown in the experimental results.