基于微波光子的可重构变频移相信号产生

提出一种基于偏振复用-双平行马赫-曾德尔调制器(PDM-DPMZM)的微波光子变频移相信号生成方案。通过改变调制器的直流偏置电压可以实现二倍频移相信号生成或者上/下变频移相信号生成,生成信号的相位仅通过控制检偏器偏振方向与调制器一个主轴之间的角度α就能实现-180°~180°的连续调谐。在光频梳的支持下,本方案可扩展为多通道独立相位调谐的系统。仿真结果表明,频率为5 GHz的射频信号在三种功能下可以分别转换为二倍频信号10 GHz、下变频信号1 GHz和上变频信号13 GHz,它们的相位可实现-180°~180°的全范围连续调谐,且不同相位下生成信号的功率响应相对平坦。

Generation of Reconfigurable Frequency-Conversion Signals with Full-Range Phase Shift Based on Microwave Photonics

In this paper, we propose a novel microwave photonic phase shifter based on a polarization division multiplexing dual-parallel Mach-Zehnder modulator(PDM-DPMZM). In this scheme, by adjusting the direct current(DC) bias voltages, the PDM-DPMZM is employed to generate a frequency-doubled or frequency up-converted and down-converted signals with their phases tuned across a full range. The phase shift is changed just by tuning the angle α between the polarizer’s polarization direction and one of the principal axes of the modulator. Supported by the optical frequency comb, the system is easy to be extended to multichannel system with independent phase tuning capability. The simulation results show that a radio frequency(RF) signal with a frequency of 5 GHz can be converted into a 10-GHz frequency-doubled signal, a 1-GHz frequency up-converted signal, and a 13-GHz frequency down-converted signal. Their phases can obtain a full-range phase shift from-180°to 180°, and the power response of the generated signal with different phase changes is relatively flat.