Wideband microwave measurement based on single-channel mapping and image-rejection mixing

A filterless microwave photonic-assisted frequency measurement scheme for instant broadband RF signal measurement is proposed and analyzed. The scheme employs single-channel mapping to save signal processing time. The channelized receiver is divided into upper and lower branches, generating a non-flat optical frequency comb and achieving single-sideband modulation, respectively. Through image-rejection mixing, the powers of the beating frequencies and the optical frequency comb lines are combined to determine the signal range, and the signal frequency can be accurately calculated. Simulations demonstrate that this scheme can measure multi-frequency and linearly frequency-modulated signals within the range of 0-40 GHz. The system has been experimentally validated with a measurement error of less than 25 MHz.