3 mm波段烟幕插入损耗测量

为了满足3mm波段烟幕辐射特性和插入损耗特性测量的需要，研制了3mm波段烟幕特性自动测量系统——3mm辐射源和3mm辐射计／接收机一体机。一体机是对Dicke型辐射计的改进，在保持毫米波辐射计接收机高频前端不变的前提下，分别为辐射特性测量和插入损耗特性测量设计了独立的被动通道和主动通道，并在窄带的插入损耗测量的主动通道增加了中频锁相环路。探讨了该系统的烟幕插入损耗特性测量方法，实验结果表明：该系统能满足3mm波段烟幕特性自动化测量的要求。

Insertion Loss Measurement of Smoke Screen at 3 mm Band

In order to fulfil the requirements for measuring radiation and insertion loss characteristic of smoke screen at 3mm band, an automatic measurement system, including a transmitter and an integrated 3mm band radiometer/receiver is developed. The integrated radiometer/receiver is implemented with the following modifications of a Dicke-type radiometer, for example, its millimeter-wave front-end is maintained and two independent channels, one for passive and the other for active, are designed for radiometer and insertion loss measurement receiver, respectively. An additional phaselock-loop at intermediate frequency is employed for the narrow band active channel for insertion-loss measurement receiver. A measurement method for insertion loss is introduced, and the results show that the integrated system works well in the measurement of smoke screen at 3 mm band.