设计了面向Ka频段(30 GHz)相控阵天线的4阵元子阵集成波导光延时网络。该光延时网络采用相位调制方式将射频信号转换至光域,波导微环处于反谐振状态,以实现大带宽、连续可调延时;通过带通滤波仅对一个边带进行延时调控,基于差分平衡探测器还原出射频信号。优化设计了级联双波导微环的结构参数,使每条路径的延时量在0~24.9 ps范围内连续可调,延时带宽大于4 GHz,实现了最大扫描角为±30°的波束扫描。对光延时网络链路的增益和噪声系数进行了推导分析,评估了整个延时芯片系统在实际应用中的性能。

The integrated waveguide optical delay network for four-element sub-phased array antenna at Ka band (30 GHz) is designed, in which, the radio frequency (RF) signal is converted into the optical domain by the phase modulation and the waveguide micro-rings operate at the anti-resonance state to achieve large bandwidth and continuously tunable time delay. Only one sideband is delayed via the bandpass filtering and the RF signal is recovered by the differential balanced detector. The structural parameters of the cascaded dual waveguide micro-rings are optimized to achieve the continuously tunable time delay in the range from 0 to 24.9 ps, and the bandwidth is larger than 4 GHz. The beam scanning with the maximum scaning angles of ±30° is realized. The gain and noise coefficients of the optical time delay network are analyzed and deduced, and the performance of the whole delay chip system in the practical application is evaluated.