PROJECT TITLE :

Integrated Wideband Self-Interference Cancellation in the RF Domain for FDD and Full-Duplex Wireless

ABSTRACT:

A fully integrated technique for wideband cancellation of transmitter (TX) self-interference (SI) within the RF domain is proposed for multiband frequency-division duplexing (FDD) and full-duplex (FD) wireless applications. Integrated wideband SI cancellation (SIC) within the RF domain is accomplished through: one) a bank of tunable, reconfigurable second-order high-Q RF bandpass filters in the canceller that emulate the antenna interface’s isolation (basically frequency-domain equalization in the RF domain) and 2) a linear $N$-path $G_m$-$C$ filter implementation with embedded variable attenuation and section shifting. A 0.eight–1.four GHz receiver (RX) with the proposed wideband SIC circuits is implemented during a sixty five nm CMOS method. In measurement, $>20;textMHz;20;textdB$ cancellation bandwidth (BW) is achieved across frequency-selective antenna interfaces: one) a custom-designed LTE-like zero.780/0.895 GHz duplexer with TX/RX isolation peak magnitude of thirty dB, peak cluster delay of eleven ns, and seven dB magnitude variation across the TX band for FDD and a couple of) a one.4 GHz antenna pair for FD wireless with TX/RX isolation peak magnitude of 32 dB, peak cluster delay of 9 ns, and three dB magnitude variation over one.36–one.thirty eight GHz. For FDD, SIC enhances the effective out-of-band (OOB) IIP3 and IIP2 to $+text25text-27;textdBm$ and $+90;textdBm$, respectively (enhancements of 8–ten and twenty nine dB, respectively). For FD, SIC eliminates - X gain compression for as high as $-8;textdBm$ of peak in-band (IB) SI, and enhances effective IB IIP3 and IIP2 by 22 and fifty eight dB.