Multifrequency measurement system with no frequency ambiguity based on two frequency-space mappings

Multifrequency measurement system with no frequency ambiguity based on two frequency-space mappings has been designed and investigated. By simultaneously mapping the unknown frequencies with a certain frequency shift onto non-flat optical frequency combs (OFCs) and obtaining two beat frequency signals using two balanced photodetectors (BPD), the channel where the measured signal is located can be determined, achieving instantaneous measurement of multifrequencies while effectively addressing five possible types of frequency ambiguity. Simulation results indicate that when the comb line spacing of the OFC is designed as 2 GHz, the measurement range of the system is 0.1 to 30 GHz, with a measurement error within ±1 MHz and a measurement resolution of 2.7 MHz. Furthermore, by adjusting the comb line spacing of the OFC to 4 GHz, the frequency measurement range can be extended to 60 GHz.