A 4 × 4 Fully Integrated RF Transceiver in 6 GHz Frequency Band With Single-Channel Bandwidth of 400 MHz and PHY Data-Rate of 8.8 Gbps

This brief presents a fully integrated CMOS $4\times 4$ MIMO RF transceiver (TRX) with single-channel bandwidth (BW) of 400 MHz in the 6 GHz band (5.925-7.125 GHz). In the receiver (RX) frontend, an improved noise-canceling low noise amplifier (LNA) and a cross-coupled transconductance $(G_{M})$ with IIP2 enhancement is implemented. In the transmitter (TX) frontend, a power amplifier driver (PAD) is integrated with cascade AM-PM distortion compensation to eliminate the AM-PM distortion. A hierarchical LO distribution network is employed in the 1-to-4 LO distribution chain to enhance the consistency among the LO branches. The single-chip TRX is reconfigurable for TDD/FDD operation, with the RX exhibiting a noise figure of 3.5-4.1 dB, a gain control range of 45 dB with 1 dB step and ±0.2 dB gain flatness. The TX output spectrum exhibits >32 dBc signal to noise ratio (SNR). The RX and TX error vector magnitudes (EVMs) are −30.2 dB and −30.5 dB, respectively, with 160 MHz BW 256QAM. A TX-to-RX PHY data-rate of 8.8 Gbps based on $4\times 4$ MIMO is achieved, with other major parameters comparable to the prior arts without resorting to digital calibration circuits.