Digital GaN-based Transceiver Module for Future Green 5G Networks

This paper introduces a novel GaN-based digital transceiver (TRx) concept for 5G applications, featuring a low-noise amplifier with integrated switching capability (LNAiS) and a true digital class-E power amplifier (PA) on one single chip. The LNAiS employs two common-gate stages that can be switched from low-noise amplification to high isolation mode. Thereby, a usual antenna switch can be omitted, reducing module complexity and required chip size. In Rx-mode, the LNA shows a gain of 12.7 dB and a low noise figure of 3 dB at 4.7 GHz. In OFF state, i.e. Tx-mode, it provides an isolation of more than 20 dB for 4.7 GHz to 7.4 GHz. In this mode, the very compact and flexible digital class-E PA achieves efficiencies of 46% and 23% for 20 MHz 6.5 dB LTE and 9 dB OFDM signal at 4.7 GHz center frequency, respectively. For 240 MHz 10 dB PAPR OFDM input signal, the PA reaches 22% efficiency. The proposed concept enables a very compact and flexible TRx for future 5G networks targeting a greener ICT.