A Simultaneous Transmit-Receive Quadrature Balanced RF Front-End with Wideband Digital Self Interference Cancellation

This paper presents a quadrature balanced RF Front-End transceiver architecture and a digital self-interference cancellation algorithm for simultaneous transmit-receive in next generation Half-duplex and Full-duplex radios. Tx-Rx isolation of >57dB is measured for CW signals over 80MHz BW, and >40dB for an actual 80MHz 802.11ac OFDM signal within the 2.4GHz Wi-Fi band, along with EVM of -37dB of the Tx signal for a concurrent Tx-SIC operation. Measured Rx loss is lower than 1.8dB within the operating frequency band.