有源相控阵天线系统噪声系数仿真研究

根据有源相控阵天线接收链路的模型，研究并推导了基于威尔金森馈电网络的有源相控阵天线接收等效噪声系数。通过分析幅度加权、信号合成损耗等对噪声系数的重要影响，并把有源相控阵天线等效为一个多端口网络，从而得到了等效噪声系数在雷达工程上的新公式。在此基础上，对一个8通道的相控阵天线进行了计算，并和ADS的仿真结果进行了对比，结果显示该公式的计算结果、仿真结果基本一致。计算结果还和实验结果进行了对比，在误差允许的范围内基本一致，从而证明了该公式的正确性，为工程设计提供了理论依据。

Simulation Study on System Noise Figure of Active Electronically Scanned Array Antenna

According to the model of the receiving chain of active electronically scanned array (AESA) antenna, the equivalent noise figure based on Wilkinson divider feeding system is studied and derived. The influences of amplitude weighting and signal synthesis loss on the noise figure are analyzed in this paper. Then we get a new formula of the equivalent noise figure in radar engineering using the antenna as a multi-port network. On the basis the noise figure of an antenna with eight elements is calculated. The computed results of this formula are almost the same as the simulation results in ADS. Also the calculation result is compared with the experimental result. The conclusion shows that they are basically consistent within the margin of error, which proves the correctness of this formula. The new formula provides a theoretical foundation for engineering design.