AlGaN/GaN Based Ultra-wideband 15-W High-Power Amplifier with Improved Return Loss

An ultra-wideband microwave monolithic integrated circuit high-power amplifier with excellent input and output return losses for phased array jammer applications was designed and fabricated using commercial 0.25-mu m AlGaN/GaN technology. To improve the wideband performance, resistive matching and a shunt feedback circuit are employed. The input and output return losses were improved through a balanced design using Lange-couplers. This three-stage amplifier can achieve an average saturated output power of 15 W, and power added efficiency of 10% to 28%, in a continuous wave operation over a frequency range of 6 GHz to 18 GHz. The input and output return losses were demonstrated to be lower than -15 dB over a wide frequency range.