噪声系数是影响雷达接收机性能指标的主要参数之一，与雷达的作用距离紧密相关。文中采用将多端口网络转化为二端口网络的基本思想，对相控阵雷达接收系统的噪声特性以及增益进行了分析。首先，求出多端口网络的等效增益；再基于噪声系数的基本定义推出相控阵接收系统的噪声系数计算式；同时，基于等效的思想，提出了多端口网络噪声系数以及增益的直接测量方法；最后，用仿真以及实验验证了该计算及测量方法。

As one of the key parameters affecting the performance indexes of the radar receiving system, noise figure is closely related to the radar detection range. With the theory of equivalent conversion of a multi-port network model into a two-port network model, noise characteristic and gain of the phased array radar receiving system is analyzed and measured. Firstly, the equivalent gain of the multi-port network is computed by the equivalent theory. Then, based on the original definition of the noise figure, the formula of noise figure is deduced. At the same time, based on the equivalent theory, a direct measurement method of the noise and gain is presented. Finally, the method of computing and measuring noise figure and gain is verified by simulation and experiment.

TN958.92