灵敏的毫米波辐射计接收机能够接收地物、人为目标或大气等辐射或反射的微弱电磁能量,并提供描绘目标噪声温度的直流输出〔1〕～〔4〕。就电路的方块图而言,辐射计的设计与人们所熟悉的超外差接收机极为相似。然而,它们之间的差别是极大的。例如,辐射计的灵敏度并不是以信号的电压为多少微伏来衡量,而是以可以区分的最小噪声温度的变化来衡量。精心设计的辐射计,其灵敏度 Sensitive millimeter-wave radiometer receiver to receive objects, artificial or atmospheric radiation or reflected weak electromagnetic energy, and provide the target noise temperature of the DC output [1] ~ [4]. In terms of the block diagram of the circuit, the design of the radiometer is very similar to the familiar superheterodyne receiver. However, the difference between them is enormous. For example, the sensitivity of a radiometer is not measured in terms of how many volts the signal is at, but in terms of a distinguishable minimum noise temperature change. Well-designed radiometer, its sensitivity