PROJECT TITLE :

A Wideband Highly Integrated and Widely Tunable Transceiver for In-Band Full-Duplex Communication

ABSTRACT:

A totally integrated wideband active duplexing transceiver with baseband noise-cancelling duplexing LNAs is presented. The circuit allows in-band full duplex operation with concurrent reception and transmission in the same band or closely-spaced channels. A passive mixer-initial architecture is applied here, sharing one passive mixer to perform simultaneous up-conversion and down-conversion. The bi-directional transparency of the passive mixer permits the duplexing function to be implemented at baseband instead of RF front finish. Underneath the identical condition as required for noise cancellation, the baseband duplexing LNAs buffer the transmitter input signals to the mixer whereas canceling those signals in receive path. Measurements from the transceiver implemented in 65 nm CMOS show a frequency tuning range of zero.one–1.5 GHz with twenty dB, NF as low as five.5 dB and transmitted power up to 7.1 dBm. A thirty dB linear isolation between receive and transmit is generally maintained across each LO frequency and in-band transmit/receive frequency separation. Vital suppression of transmit-induced noise and nonlinear intermodulation between received and transmitted signals are achieved.