Microwave photonic channelizer based on dual optical frequency combs for instantaneous frequency measurement of broadband microwave signals

A broadband photonic channelized receiver based on dual optical frequency combs (OFCs) has been proposed and investigated for the instantaneous frequency measurement (IFM) of a broadband microwave signal. In the first branch, the generated five-line flat OFC is input into the dual parallel Mach-Zehnder modulator (DPMZM) for carrier-suppressed single-sideband (CS-SSB) modulation, resulting in the unknown broadband signal being modulated onto the five-line OFC. In the second branch, the other generated frequency-shifted five-line flat OFC is input into the optical I/Q receiver via the demultiplexer and performs the beat frequency processing with the unknown broadband signal. Simulation experiments show that by using the channelized receiver, the QPSK signal with a bandwidth of 8 GHz and a central frequency of 20 GHz is successfully divided into eight sub-channels with a center frequency of 1.5 GHz and a bandwidth of 1 GHz, yielding an intermediate frequency (IF) channelization reception. By adjusting the frequency of the reference signal, the system can be used to measure the broadband signal with central frequencies within 4-36 GHz. In addition, the system image suppression ratio is greater than 63 dB, with the passband power fluctuation less than 1.1 dB.