A photonic-assisted approach for instantaneous frequency measurement based on optical power monitoring is proposed and demonstrated. Instead of using optical filter, a dual-polarization Mach–Zehnder modulator is used to modulate the unknown RF signal with a designed electrical time delay. Due to the property of electrical time delay, the frequency information is firstly converted to phase shift and then to the optical power. By monitoring the optical power, a monotonic relationship between the incident microwave frequency and optical power ratio can be easily established. A detailed theoretical analysis is carried out to illustrate the mechanism of the proposed instantaneous frequency measurement setup. Simulation has been performed to investigate the tuning of measurement range and the impact of imperfection devices. A proof-of-concept experiment has been carried out to verify the mechanism.

中文翻译：

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基于偏振干涉的光功率监测瞬时微波频率测量

提出并演示了一种基于光功率监测的瞬时频率测量光子辅助方法。不使用滤光器，而是使用双极化 Mach-Zehnder 调制器来调制具有设计电时间延迟的未知 RF 信号。由于电时延的特性，频率信息首先转换为相移，然后转换为光功率。通过监测光功率，可以很容易地建立入射微波频率和光功率比之间的单调关系。进行了详细的理论分析以说明所提出的瞬时频率测量设置的机制。已执行仿真以研究测量范围的调整和缺陷设备的影响。