宽带相控阵天线延迟线分析

采用频率无关移相器的相控阵天线的波束指向会随频率发生变化，实时延迟线是提高宽带相控阵天线波束指向精度的重要方法。分析了子阵级采用延迟线，单元级使用移相器的宽带相控阵天线副辫特性，发现当工作频率改变时，由于阵列存在周期相位误差导致天线副瓣电平抬高。针对此问题，提出单元级精细延迟线方案，消除周期相位误差对天线副瓣的影响。仿真结果表明，这种方法在扩展相控阵天线带宽的同时，明显改善了天线的副瓣特性。

Analysis of TTD for Wideband Phased Array

The beam pointing of phased array antennas that adopt irrelevant-frequency phased shifters is changed with frequency. The true time delayer（TTD） for wideband phased array is an important method to improve the beam-pointing accuracy. For wideband phased array using phase shifters at elements and true time delays at subarray, sidelobe performance is deteriorated because of periodic phase error. For solving the problem, the fine TTD is used at element. The simulation results shown that the bandwidth of phased array antennas can be expanded effectively, at the same time, array sidelobe level is reduced by fine TTD used at element.