微波光子移相器辅助的均匀圆形相控阵测向

Uniform Circular Phased Array Direction Finding Based on Microwave Photonic Phase Shifters

为克服传统电域移相器工作频段低、带宽窄、体积功耗大、易受电磁干扰等诸多缺陷,实现多个时频重叠微波信号的波达方向估计,提出一种基于双平行马赫曾德尔调制器(DPMZM)的微波光子移相器方案,利用光子技术实现微波信号移相,再利用均匀圆形阵列相控阵实现测向。分别利用DPMZM和相位调制器(PM)输出一路抑制载波单边带(CS SSB)信号和一路相位偏移的载波信号,通过调整直流偏置电压调控载波信号的相移值,再利用拍频产生预设相移的微波信号。该移相器方案能实现-180°~180°的连续相位调谐,同时输出幅度稳定的微波信号,能够适用于相控阵测向。通过仿真验证了所提微波光子移相器及相控阵测向算法的性能。

To overcome the electronic bottlenecks issues of conventional electronic phase shifters,such as low operating frequency,narrow bandwidth,large size,heavy weight and susceptible to electromagnetic interference,a direction finding technique based on uniform circular phased array was proposed to estimate the directions of arrival of multi microwave signals with the same time and frequency.The photonic technique was utilized for phase shift,which used for direction finding by phased array scheme.A scheme of microwave photonic phase shifter using dual-parallel Mach-Zehnder modulator(DPMZM)was presented.In this scheme,one carrier single-sideband(CS-SSB)and one optical carrier with a phase shift had been realized by a DPMZM and one Phase Modulator(PM).The phase variation of the carrier signal has been adjusted by changing the bias voltage of the PM.Then the phase shifted microwave signal could be obtained by beating the two signals at a photodiode.The presented microwave photonic phase shifter scheme could achieve a tunable phase shift from -180°to 180°.Also,the photonic phase shifter had a flat power response,which was appropriate for phased array direction finding.Finally,the performance of the direction finding algorithm and the availability of the proposed microwave photonic phase shifter had been verified by some simulations.