A Band-Shifting Millimeter-Wave T/R Front-End with Enhanced Imaging and Interference Rejection Covering 5G NR FR2 n257/n258/n259/n260/n261 Bands

For achieving multi-band fusion within the fifth-generation (5G) new radio (NR) frequency range 2 (FR2), a band-shifting transmit/receive (T/R) front-ends (FEs) with the reconfigurable auxiliary paths, covering n257/n258/n259/n260/ n261, is proposed in this paper. To overcome the deterioration from capacitance-based frequency tuning, an inductance-mutation transformer technique is proposed in the interstage matching of both TX and RX FEs, to enable operation band shifting between low frequency (LF) and high frequency (HF). The proposed transceiver FE chip, composed of a differential power amplifier (PA) with cascade output stage, a two-stage cascade low-noise amplifier (LNA), and a compact dual-resonance T/R switch at antenna interface, is designed and fabricated in standard 28-nm CMOS process. The measured results show the FE can cover 24.25-29.5/37-43.5GHz at LF/HF with enhanced interference and imaging rejection, and realizes <-25 dB EVM for 400 Msym/s 64-QAM wireless communication with >9 dBm average output power in the target band.