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

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