A compact and low-complexity power amplifier at sub-6 GHz band for 5G application

This paper proposed a compact and low-complexity power amplifier (PA) at sub-6 GHz band, which is prospective for future 5G applications. Two important specifications are required for the PA in the 5G system are high efficiency and compact size. To obtain high efficiency, one of the most popular solutions is the treatment of high-order harmonics. The harmonic treatment techniques are applied to the input/output matching networks, making the PA complex and bulky. With a trade-off between high efficiency and compact feature, our method only focused on optimizing the PA’s parameters at fundamental frequency. The input and output matching circuits were designed by using step-impedance quasi-Chebyshev lowpass matching method. The cosimulation results showed that the PA achieved the peak power added efficiency (PAE) of 60.7%, the output power of 36.9 dBm, and the power gain of 14.9 dB at 6 GHz. In the bandwidth of 200 MHz between 5.9 GHz and 6.1 GHz, the peak PAE was more than 58%.