Design and Fabrication of a High-Efficiency and High-Gain X-Band Power Amplifier Using GaN-HEMT Die Transistors for Satellite Communications

In this paper, the design and fabrication of a hybrid microwave integrated circuit (HMIC) power amplifier (PA) with more than 8 Watts of output power and 50 dB of large signal gain in the frequency range of 10.95-11.20 GHz for satellite communications is presented. In order to have a high-efficiency PA, the last two stages of the PA are custom designed and fabricated using GaN transistors as separate modules. To evaluate the repeatability of the designed PA, 16 samples of the custom-designed PA are fabricated and measured. All of the measured PAs provided 8 Watts of output power with more than 55% of power added efficiency (PAE). To have a gain of more than 50 dB, commercial integrated circuits (ICs) are used as gain stages. Finally, the performance of the fabricated PA is evaluated using a 10 MSym/s QAM signal and 6 Watts of average output power with 33% of efficiency is achieved at 11 GHz.