基于相干激光的分谐波混频器数学模型构建

Mathematical model construction of subharmonic mixer based on coherent laser

分谐波混频器在相干接收系统中具有重要作用,为了有效提高接收机整体性能,构建基于相干激光的分谐波混频器数学模型。建立相干激光通信系统,系统光路使用通信用光纤器件组成,利用I&Q调制器正交调制与带宽合成信号技术,令系统可同时满足大带宽、高重复频率请求;解析分谐波混频器原理,为后续模型构建提供理论支撑;最后通过研究分谐波混频器射频输入的负增益、本振端开关及各端口耦合非线性效应,创建分谐波混频器数学模型。仿真实验证明了分谐波混频器数学模型的误码率平均值为le-17BER,变频损耗平均值为7.34 dB,平均通信效率为93%,能够为各种光学元件摆放位置和相对角度补偿调整提供借鉴与参考,具备一定的指导意义。

The subharmonic mixer plays an essential role in the coherent receiving system.In order to improve the overall performance of the receiver,the mathematical model of the subharmonic mixer based on the coherent laser is constructed.The optical path of the system is composed of optical fibre devices for communication.The orthogonal modulation of the I&Q modulator and bandwidth synthesis signal technology is used to make the system meet the requirements of considerable bandwidth and high repetition frequency at the same time.The principle of the subharmonic mixer is analysed to provide theoretical support for the subsequent model construction.Finally,the negative gain and local vibration end of RF input of subharmonic mixer are studied.A mathematical model of the subharmonic mixer is established by coupling non-linear effects of switches and ports.The simulation experiment proves that the average error rate of the subharmonic mixer’s mathematical model is le-17 BER,the average conversion loss is 7.34 dB,and the average communication efficiency is 93%.The compensation adjustment provides reference and has particular guiding significance.