Measurement and analysis of instantaneous microwave frequency based on an optical frequency comb

A microwave photonics instantaneous frequency measurement scheme with 14 channels based on an optical frequency comb (OFC) is proposed. In this scheme, a 14-line flat OFC is generated by cascading a dual-parallel Mach-Zehnder modulator (DPMZM) with a Mach-Zehnder modulator (MZM). The intercepted microwave signal with multiple-frequency components can be measured by using DPMZM, Fabry-Perot filter (FPF), wavelength division multiplexer (WDM), and optical power detector array. This scheme can measure and analyze the frequency of microwave signals in the ranges of 0.5-13.5 GHz, 13.5-26.5 GHz, and 26.5-39.5 GHz with the measurement accuracy of ±0.5GHz. The reconfigurability of the system can be realized by adjusting the comb-line spacing of the OFC and the free spectral range (FSR) of the FPF.