Frequency-Domain-Equalization-based Full-Duplex Receiver with Passive-Frequency-Shifting N-Path Filters Achieving >53 dB SI Suppression Across 160 MHz BW

Wideband full-duplex (FD) transceivers pose a significant challenge as they require >100dB of self-interference cancellation (SIC) over large bandwidths. This work utilizes (i) a near-zero-power rotary clock-path passive frequency shifting technique for N-path filters while requiring only a single common LO signal across all filters, and (ii) a closed-loop adaptation algorithm to find the optimal configurations of various RF canceler filters using analytical modelling of tap non-idealities caused by frequency shifting and quality factor variations. The FD receiver achieves (i) tunable operation from 200MHz to 1GHz, (ii) wideband SI suppression of up to 53dB across 160MHz BW when operating at 720MHz (4.44x more fractional bandwidth (FBW) compared to [1]), (iii) a power consumption of 1.8mW/DoF (degree of freedom for each tap, almost 2x better than [1]), while (iv) handling TX power of up to +15dBm across an initial circulator isolation of 26dB.