Photonic-assisted multiple microwave frequency measurement with improved robustness

Abstract

A multiple microwave frequency measurement approach based on frequency-to-time mapping (FTTM) is reported. The FTTM is constructed by optical sideband sweeping and electric-domain intermediate frequency envelope monitoring. Two optimized operations are implemented. First, the use of balanced photodetection cancels out the beat components generated by the signals under test (SUT) themselves, so as to exclude frequency misjudgment. Second, a reference signal is introduced to map the SUT frequency to a relative time difference instead of an absolute time value, avoiding the measuring bias caused by time synchronization. As a result, the proposed scheme with improved robustness could be attractive for future practical applications. An experiment is performed. Microwave frequency measurement from 16 to 26 GHz is demonstrated, with an average error of 7.53 MHz.

Machine-Learning-Assisted Instantaneous Frequency Measurement Method Based on Thin-Film Lithium Niobate on an Insulator Phase Modulator for Radar Detection

“…Although the system exhibits excellent measurement performance, it requires precise tuning of the micro-ring electrodes and is sensitive to ambient temperature. On the other hand, Guodong Wang [ 28 ] put forward an IFM system that mainly consists of a dual-polarization quadrature phase shift keying modulator (DP-QPSKM) and a balanced photodetector (BPD) to improve the system’s robustness. Firstly, the use of balanced photodetection cancels out the beat components generated by the unknown frequencies themselves to exclude frequency misjudgment.…”