本文介绍用射电天文方法测量天线参数的调制型(狄克式)辐射计的工作原理,分析了辐射计灵敏度与系统噪声温度和中放带宽的关系。叙述了微波辐射计接收机和雷达接收机的不同处。列出了主要的性能指标。并根据性能指标对各部件进行介绍和选择。辐射计的微波部件包括:PIN调制器、混频器、本振、环行器。其它部分:中频放大器、检波器、低 This article introduces the working principle of a modulated (Dick-type) radiometer that measures the antenna parameters using radio astronomy, and analyzes the relationship between the sensitivity of the radiometer and the system noise temperature and the mid-band bandwidth. Describes the difference between a microwave radiometer receiver and a radar receiver. The main performance indicators are listed. And according to the performance indicators for the introduction and selection of various components. Radiometer microwave components include: PIN modulator, mixer, local oscillator, circulator. Other parts: IF amplifier, detector, low