A Cost-Effective 5-W GaN HEMT Power Amplifier for Sub-6-GHz 5G Wireless Communications

In this paper, a design method of a compact, low-cost and high-efficiency microwave power amplifier for using in the 5G wireless communication applications is presented. The proposed approach is based on a combination of harmonically tuned technique to improve the efficiency and careful design of the input and output matching networks to simplify structures and miniaturize the power amplifier. The amplifier aims at operating at 5.8 GHz band using a low-cost 5 W GaN HEMT device from Qorvo. The output matching network is designed to terminate up to the third harmonic while the input matching network is designed to terminate up to the second harmonic. Both small-signal and large-signal performances of the proposed amplifier are evaluated by simulation and experiment. The simulated and measured results show that the designed power amplifier offers a compact size. The best measured input and output return losses are -9.4 dB at 6 GHz and -15.3 dB at 6.1 GHz, respectively and the best power gain is 12.9 dB at 5.7 GHz. The measured efficiency, output power and power gain at 5.72 GHz are 41.7 %, 37 dBm (5 W) and 10.5 dB, respectively.