Wideband Microwave Channelized Receiver Based on Dual Optical Frequency Comb and Photonics-Assisted Image-Reject Mixer

Abstract

A microwave photonics image rejection channelized receiver scheme based on dual optical frequency comb (OFC) is proposed. In the upper branch, the radio frequency (RF) signal is modulated by a frequency multiplier circuit to drive a Mach-Zehnder modulator (MZM) to generate a 4-line OFC. The 4-line OFC is carrier suppressed double sideband (CS-DSB) modulated by RF broadband signal to be received in MZM2. In the lower branch, the shifted optical carrier is sent to a dual-parallel Mach-Zehnder modulator (DPMZM) to generate 7-line LO OFC. In the receiving module, the image rejection is realized by the Hartley structure, and the signals of each channel are received accurately. This scheme avoids the use of the optical filter, and can flexibly choose to receive the left or right sideband signal of the LO OFC comb line. The simulation results show that the scheme can accurately receive the RF signal with the center frequency of 20GHz and bandwidth of 7GHz. The image signal can be effectively suppressed, and the image rejection ratio is greater than 25dB. This scheme is reconfigurable. The RF broadband signals in different frequency ranges can be channelization received by adjusting the comb-line spacing of OFC and the frequency shift.