基于双光学频梳的超宽带射频信号信道化合成技术研究(特邀)

Research on channelized synthesis of ultra-wideband radio frequency signal based on dual optical frequency combs(Invited)

随着现代通信系统的发展,宽带和高频微波射频信号在雷达,通信和信号处理等领域的应用越来越广泛。基于微波光子信道化技术,文中通过两个自由频谱范围不同的光学频梳,实现了超宽带射频信号的信道化合成。在信道化合成系统中,多个独立的窄带信号输入各个信道进行上变频,并在多外差探测中被重组成为一个具有连续频谱的宽带射频信号。在多外差探测中,干扰抑制技术的使用提高了合成射频信号可达到的最高频率。在实验中,合成了一个覆盖频率范围8.4~12.4 GHz,瞬时带宽为4 GHz的宽带射频信号。实验结果显示,干扰的抑制率达到了21 dB,表明干扰抑制技术的使用提高了输出信号的最高频率的同时有效地提高了频谱利用率。

With the development of the modern communication system,broadband and high-frequency microwave radio frequency(RF)signals have been widely applied in the fields of radar,communication and signal processing.Based on the microwave photonic channelization,ultra-wideband RF signals were generated through dual optical frequency combs(OFCs)with different free spectrum ranges(FSRs).In the channelized synthesis system,multiple independent narrowband signal was input in each channel for up-conversion and detected by multi-heterodyne detection to reconstruct a wideband RF signal with continuous spectrum.In multiheterodyne detection,interference suppression technique increased the highest frequency that the synthesized RF signal could reach.In the experiment,a wideband RF signal was synthesized with an instantaneous bandwidth of4 GHz,covering a frequency range of 8.4-12.4 GHz.The experiment demonstrates an interference suppression ratio of 21 dB,indicating that the interference suppression technique increases the highest frequency of the output signal and effectively improves the spectrum utilization.