Photonic-Aided Wide-Band High Precision Spectrum Analysis System Based on Polarization Multiplexing

A photonic-aided wide-band high-precision spectrum analysis system is proposed and demonstrated. The polarization multiplexing is employed to perform concurrent operation of fast frequency-to-time mapping (FTTM)-based frequency measurement (FM) and neural network-assisted signal analysis. Dual-band FTTM is implemented via chirp multiplexing and matched filtering, which enables simultaneous FM covering two 6-GHz bands. A two-step filtering architecture is designed to mitigate the impact of laser frequency drift and achieve a measurement accuracy of ±2.6 MHz with 30 kHz spectral resolution. By utilizing a YOLOv8-based network, high-precision multiparameter estimation to the signal under test (SUT) is realized with a frequency error under 0.9 MHz, a bandwidth error under 2.8 MHz, a time-center error under <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$1~\mu $</tex-math> </inline-formula>s, a duration error under <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$2.1~\mu $</tex-math> </inline-formula>s, and a modulation recognition error rate under 0.025. The proposed system combines the advantages of photonic and electrical technologies, which holds great promise for applications in intelligent RF systems for cognitive radio and spectrum management.