Incorporating radar detection and frequency measurement functions within a single system is highly desirable in modern RF applications. In this article, a microwave photonic system is proposed and demonstrated to simultaneously realize broadband radar detection and frequency measurement. By sharing a light with ± 2nd-order linear frequency-modulated (LFM) sidebands in a polarization-division-multiplexing manner, radar detection and frequency measurement functions can be realized simultaneously. In the transmitter, the shared light is used to generate a radar signal that has a quadrupled bandwidth compared with the input electrical LFM signal. In the receiver, the shared light is applied as the reference to perform photonic de-chirping of the radar echo and to scan the frequency of the signal under test (SUT) along two orthogonal polarization directions. In the experiment, a 4.5–6.5 GHz LFM signal is used to generate the shared light source, based on which radar detection (bandwidth: 18–26 GHz) with a range resolution as high as 2.06 cm, and frequency measurement (measurement range: 28–36 GHz) with a scanning rate of 0.8 GHz/μs and a resolution of 37.6 MHz are achieved. In addition, the reconfigurablilty of the frequency measurement range, and its capability for measuring the multi-tone and wideband signals are also demonstrated.

中文翻译：

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通过宽带微波光子处理同时进行雷达探测和频率测量

在现代射频应用中非常需要在单个系统中集成雷达检测和频率测量功能。在本文中，提出并演示了一种微波光子系统，可同时实现宽带雷达检测和频率测量。通过以偏振分复用方式共享具有±2阶线性调频(LFM)边带的光，可以同时实现雷达探测和频率测量功能。在发射器中，共享光用于生成与输入电 LFM 信号相比具有四倍带宽的雷达信号。在接收器中，共享光被用作参考，以执行雷达回波的光子去啁啾，并沿两个正交极化方向扫描被测信号 (SUT) 的频率。实验中采用4.5-6.5 GHz LFM信号产生共享光源，基于该信号进行距离分辨率高达2.06 cm的雷达探测（带宽：18-26 GHz）和频率测量（测量范围： 28–36 GHz)，扫描速率为 0.8 GHz/μs，分辨率为 37.6 MHz。此外，还展示了频率测量范围的可重构性及其测量多音和宽带信号的能力。18-26 GHz），距离分辨率高达2.06 cm，频率测量（测量范围：28-36 GHz），扫描速率为0.8 GHz/μs，分辨率为37.6 MHz。此外，还展示了频率测量范围的可重构性及其测量多音和宽带信号的能力。18-26 GHz），距离分辨率高达2.06 cm，频率测量（测量范围：28-36 GHz），扫描速率为0.8 GHz/μs，分辨率为37.6 MHz。此外，还展示了频率测量范围的可重构性及其测量多音和宽带信号的能力。