Radio frequency self-interference cancelation and channelized receiver based on optical frequency comb and polarization multiplexing

Abstract

A channelized receiver for radio frequency (RF) self-interference cancelation (SIC) based on optical frequency comb (OFC) and polarization multiplexing is proposed. In the upper branch, the received RF signal and the reference signal are modulated via a dual-polarization binary phase-shift keying (DP-BPSK) modulator, generating carrier-suppressed double-sideband signals on orthogonal X- and Y-polarization states, respectively. The lower branch produces a four-line OFC. After filtering, both optical signals are fed into a polarization-phase diversity coherent receiver for further processing. SIC is achieved by tuning optical-domain components, which provides higher matching accuracy than conventional electrical-domain methods. To reduce system complexity, an acoustic-optic frequency shifter replaces the traditional frequency-shifting module. Moreover, by assigning two sub-channels per OFC comb line, the required number of comb lines is halved for the same total channel count, which significantly improves integration and RF channelization efficiency. The receiver’s performance is validated through theoretical analysis and system simulations. Results show that an 8 GHz RF signal is successfully decomposed into eight 1 GHz sub-channels while performing simultaneous SIC and image rejection. The measured sub-channel isolation exceeds 29 dB, the SIC depth is >30 dB, and the image rejection ratio surpasses 43 dB. These results demonstrate the potential of the proposed architecture for high-performance, multichannel RF signal processing in applications such as in-band full-duplex systems.