频率可调的双路相位编码微波信号系统

Double Channel Phase-coded Microwave Signal System with Frequency Tunability

提出一种在单输入情况下同时产生两路任意相位编码微波信号的方法,不仅可以保证编码信号180°的相移,还可实现编码信号的频率大范围调谐.建立由一个双平行马赫曾德调制器和一个保偏布拉格光栅组成的系统,激光输入双平行马赫曾德调制器调制后,通过保偏布拉格光栅与偏振分束器的共同作用产生两路偏振正交的±2阶边带.其中一对边带经过相位调制器调制后与另一对耦合,最后输出两个光电探测器拍频得到高频率、低噪声的相位编码微波信号.仿真结果表明,通过调节驱动信号的频率,可得到5~100 GHz的一系列四倍频相位编码微波信号.还原的相位信息与脉冲压缩比均和理论值吻合,证明了所提方法具有良好的脉冲压缩性能.

A photonic approach to generating two arbitrary and preciselyπphase-shifted phase-coded microwave signals simultaneously with large frequency tenability in a single input case is proposed and demonstrated.The scheme is mainly consists of one dual-parallel Mach-Zehnder modulator and one polarization-maintaining fiber Bragg grating.After the laser inputs dual-parallel Mach-Zehnder modulator,the polarization-maintaining fiber Bragg grating and polarization beam splitter are combined to obtain two polarization orthogonal sidebands.One pair of side bands is modulated by the phase modulator and then coupled to the other pair.Finally,input them into two photodetectors to obtain high-frequency,low-noise encoded microwave signals.The simulation result shows that,by adjusting the frequency of the driving signal,a series of quadruplicated frequency phase-coded microwave signals of 5~100 GHz can be obtained.The recovered phase information and pulse compression ratio agree well with theoretical values,proving the good pulse compression performance of the proposed method.