Wideband Photonic RF Transceiver with Zero-IF Architecture

Radio frequency (RF) transceivers with zero intermediate frequency (IF) architecture feature the advantages of frequency agile, large bandwidth, simple structure and easy integration, but suffer from local oscillator (LO) leakage, dc offset, even-order distortion, in-phase/quadrature (I/Q) imbalance. A wideband zero-IF transceiver based on photonic I/Q mixing techniques is proposed. In the experiment, RF vector signals with a carrier frequency of 36 GHz and a symbol rate of 100 MSym/s are successfully generated in the zero-IF transmitter and demodulated in the zero-IF receiver. Due to the good RF/LO isolation and balanced detection in the receiver, the dc offset and even-order distortion are well suppressed. Thanks to the all-optical frequency mixing and phase shifting techniques, a wide operating frequency from 7 to 40 GHz is obtained, with the I/Q amplitude imbalance below 0.5 dB and the phase imbalance below 0.9 degree.