A 5-7.1 GHz 4-Channel CMOS Wi-Fi 7 Transceiver Front-End for Fiber-to-the-Room with Analog Beamforming and Digital Pre-Distortion

This paper presents a 5-7.1 GHz 4-Channel CMOS transceiver front-end with multiple-input-multiple-output (MIMO), 1:2 and 1:4 beamforming, and digital pre-distortion (DPD) for fiber-to-the-room (FTTR) Wi-Fi 7 solution. Each channel consists of a transmitter (TX), a receiver (RX), and a jointly designed T/R switch. The TX employs a high-linearity power amplifier (PA), a variable-gain amplifier (VGA), a 5-bit passive attenuator (ATT), and a 4-bit passive phase shifter (PS). The RX is composed of a variable gain low-noise amplifier (LNA), a stagger-tuned VGA, a 5-bit ATT and a 4-bit PS. The power divider (PD) and power combiner (PC) are realized by a passiveactive hybrid network scheme. Implemented in a 55-nm CMOS technology, the measured Psat of each TX channel is better than 22.1 dBm. The error vector magnitude (EVM) of the TX with 320-MHz 4096-QAM MCS13 is better than −40.31 dB at 17.5-dBm output power, while the EVM floor is below -38 dB within the 5 to 7.1 GHz range with output power of -16 to 20 dBm. The EVM of the RX at −19 dBm input power is better than −46.41 dB. The RX noise figure (NF) is 4.5 dB.