Radio frequency (RF) repeaters are often used in satellite communication, wireless wideband communication, and electronic warfare systems for signal receiving, forwarding, and processing. Due to frequency-dependent microwave devices, conventional electrical RF repeaters have limited bandwidth and are susceptible to electromagnetic interference. In this article, a dual-channel photonic RF repeater using a polarization-division multiplexing dual-parallel Mach–Zehnder modulator is proposed. The RF repeater is built entirely using optical methods and does not require any frequency-dependent equipment, thus enabling high operating frequency and large operating bandwidth. The modulator is used to perform frequency conversion on the received uplink/downlink RF signals, and the followed polarization controller and the balanced photodetector realize switching of the uplink and downlink RF channels. In the experiment, wide operating bandwidth (1–20 GHz), low channel crosstalk (>33 dB), and a large spurious-free dynamic range (106 dB·Hz2/3) for the RF repeater are obtained. Also, the channel switching of 16 quadrature amplitude modulation (QAM) RF signals with 200 Mbps data rate is demonstrated, while the adjacent channel power ratio (ACPR), demodulated constellation diagrams, and the error vector magnitude (EVM) are evaluated.

中文翻译：

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基于偏振分复用调制和偏振控制的宽带双通道光子射频中继器

射频 (RF) 中继器通常用于卫星通信、无线宽带通信和电子战系统，用于信号接收、转发和处理。由于频率相关的微波设备，传统的电子射频中继器的带宽有限并且容易受到电磁干扰。在本文中，提出了一种使用偏振分复用双并行 Mach-Zehnder 调制器的双通道光子射频中继器。射频中继器完全采用光学方法构建，不需要任何与频率相关的设备，从而实现高工作频率和大工作带宽。调制器用于对接收到的上下行射频信号进行频率转换，其后的偏振控制器和平衡光电探测器实现上下行射频信道的切换。在实验中，射频中继器获得了宽工作带宽（1-20 GHz）、低通道串扰（>33 dB）和大的无杂散动态范围（106 dB·Hz2/3）。此外，还演示了具有 200 Mbps 数据速率的 16 个正交幅度调制 (QAM) 射频信号的通道切换，同时评估了相邻通道功率比 (ACPR)、解调星座图和误差矢量幅度 (EVM)。