分布式天线阵列中的参考相位稳定方法

Reference Phase Stabilizer in Distributed Antenna Array

光纤已被广泛研究作为在分布式阵列天线系统中向远程天线传播参考信号的有效手段。分布式阵列天线的一个关键问题是由不同天线接收的参考信号遭受由光纤长度变化以及外部环境变化引起的相位偏差,造成天线间的参考相位不同步。提出一种基于光纤的分布式阵列参考相位稳定方法,基于光纤的反馈回路来监控相位差,使用对称布置在前向通道和反馈通道上的移相器来连续地补偿相位差,实现了天线之间参考相位误差的有效连续补偿。仿真和实测结果表明,所提方法解决了分布式天线阵列光纤长度变化以及外部环境变化引起的相位偏差,当光纤分发10 MHz参考信号时,测试可得分布式天线之间的剩余相位误差小于±0.02°。

Optical fiber has been extensively studied as an effective means to disseminate reference signal to remote antennas in distributed antenna array systems.A crucial problem with distributed array is that the reference signals received by different antennas suffer from phase misalignment caused by the fiber length variations.In this paper,a fiber based phase stabilizer method is proposed to counteract the reference phase differences among antennas.This method uses fiber based feedback loop to monitor the phase differences.Then phase shifters,which are symmetrically arranged on the forward lane and feedback lane,are used to continuously compensate for the phase difference.Both analysis and experimental results suggest that the proposed phase stabilizer can achieve satisfactory performance.When the optical fiber distributes the 10 MHz reference signal,the remainder phase difference by implementing proposed method is less than±0.02°.