基于相干双光频梳的微波光子信道化接收技术研究

Research on microwave photonic channelization receiving technology based on dual coherent optical frequency comb

为了满足宽带通信的发展需求,提出了一种基于相干双光频梳的微波光子信道化接收机,所用的光频梳仅需一个双平行马赫−曾德尔调制器就可生成,平坦度高,外带抑制比高,自由谱范围灵活可调,并且有效简化了接收机的复杂程度。在I/Q解调模块中,利用平衡探测方法不仅有效抑制了二阶交调失真和直流偏移,还提高了接收机的动态范围,同时利用电耦合器配合电带通滤波器解决了超外差架构普遍存在的镜像干扰问题,最终实现了5 GHz带宽射频信号的信道化接收。

In order to meet the future development needs of broadband communications,a microwave photonic channelization receiver based on dual coherent optical frequency comb(OFC)was proposed.The used optical frequency comb can be generated by only a dual parallel Mach-Zehnder modulator(DPMZM),which not only has high degree of flatness and out band rejection ratio,flexible and adjustable free spectrum range,but also effectively simplifies the complexity of the receiver.In the I/Q demodulation module,by the balanced detection method the second-order intermodulation distortion(IMD2)and direct current(DC)offset were effectively suppressed,and the dynamic range of the receiver was improved,at the same time,the electrical hybrid couple(EHC)and electric bandpass filter(EBPF)were used to solve the problem of image interference that is common in superheterodyne architectures.Finally it achieves channelized reception of 5 GHz bandwidth RF signals.