以被动式毫米波成像为应用背景, 介绍了辐射计的工作原理, 成功研制了一种带宽 35 GHz集成直接检波式辐射计原理样机, 以满足成像系统对辐射计的需求。信号由两级低噪声放大器进行放大, 再由检波器直接检波, 最后进行视频放大, 以提供足够高的信号供后端进行数据采集。放大器由两级低噪声放大器组成, 放大增益 40 dB。单独对检波器进行设计、测试, 在 75~100 GHz范围内, 该检波器电压灵敏度大于 1 000 mV/mW, 在 100~110 GHz范围内, 电压灵敏度大于 500 mV/mW。最后集成了一个整体辐射计模块, 该辐射计在 35 GHz带宽内积分时间为 0.6 ms, 温度灵敏度为 0.45 K。

The working principle of radiometer is introduced, and a principle prototype of 35 GHz bandwidth integrated direct detection radiometer is developed, in order to meet the demand for radiometer imaging system. The signal is amplified by a two-stage low noise amplifier which gains 40 dB, then directly detected by the detector, and finally amplified by video amplifier. The design and testing are performed separately to the detector, with detector voltage sensitivity at 75-100 GHz greater than 1 000 mV/mW, at 100-110 GHz greater than 500 mV/mW. A radiometer is completed. Response over 35 GHz band, integration time of 0.6 ms and temperature sensitivity of 0.45 K are achieved.