星载SAR波控系统设计与验证

Design and verification of beam-steering system in space-borne SAR

为解决星载合成孔径雷达(SAR)相控阵天线中成千上万个微波组件的可靠性控制问题,提出一种基于并行链式拓扑的波控系统设计方案。该方案采用链式拓扑总线简化单元互联,实现轻量化设计;提出接收电路归一化方法,实现波控单元对等互换;从直流偏置、故障隔离和同步传输三方面阐述了预防接口电路失效的可靠性设计措施。测试结果表明,当接收芯片阈值为400 mV时,直流偏置电阻值小于690Ω,能避免接收端输出不定态;当总线中任意接收端失效时,串接1 kΩ隔离电阻,能避免总线通信瘫痪;当接收数据时钟下降沿均位于数据码元的1/2长度时,同步传输无误码。研究结果可以为后续星载大型相控阵雷达波控系统以及其他类似航天载荷的可靠性设计提供参考。

In order to solve the reliability control problem of thousands of microwave modules in the space-borne Synthetic Aperture Radar(SAR)phased array antenna,a design scheme of beam-steering system based on parallel chain topology is proposed.This solution uses a chain topology bus to simplify unit interconnection and realize lightweight design.It proposes a normalization method of the receiving circuit to realize peer-to-peer interchange of the beam-steering unit,and elaborates the reliability design measures to prevent interface circuit failure from the aspects of DC bias,fault isolation,and synchronous transmission.The test results show that when the threshold va lue of the receiving chip is 400 mV,the DC bias resistance value should be less than 690Ωto avoid the output instability at the receiving end;when any receiving end in the bus fails,a 1 kΩisolation resistor can be connected in series to prevent the b us communication from being disabled;when the falling edge of the clock is located at 1/2 of the length of the data symbol,the transmission is error-free.The research results can provide a reference for the reliability design of subsequent space-borne large phased array radar beam-steering systems and other similar space loads.