水基附着介质罩对毫米波衰减的理论分析与实验研究

本文主要研究多种可能出现的天线罩水基附着介质对毫米波所产生的衰减.本文采用一个四层介质模型来模拟水附着在天线罩上的情况，根据Fresnel方程得到150 GHz和298 GHz电磁波衰减模型，通过测量纯水对毫米波所产生的衰减验证模型的正确性；再测量雨水、海水所产生的衰减，分析常见水基附着介质对毫米波所产生的衰减；最后测量不同盐度的海水对毫米波所产生的衰减，分析了海水盐度对衰减的影响.实验结果证明毫米波的衰减随着天线罩上附着水层厚度的增加呈现出较为规律性增长，而此衰减受中水中溶解物（微小颗粒和盐度）的影响较小.本文对毫米波雷达在雨天等复杂室外条件下的应用具有一定的指导作用.

Theoretical Analysis and Experimental Study of Attenuation at Millimeter Wave Frequency by Water-Based Medium Radome

The attenuation at millimeter wave frequencies due to water contamination within a radar system is investigated in this paper.A model consisting of four layers of a potential contaminant is adopted in order to simulate the scattering behavior when water deposits are present with a radome.An attenuation parameter based on the Fresnel principle is proposed at 150GHz and 298GHz,which is supported by measurements that are obtained from pure water experiments.The attenuation due to realistic water-based contaminants in a typical outdoor environment,such as rain water,is measured and analyzed;furthermore,attenuations through sea water with different salinity is measured and analyzed.The experimental results show that the attenuation produced by radome water deposits increases with water thickness and this attenuation is not heavily dependent on the particles,such as dirt and salt,within the water-based liquid.The results presented are important in determining the feasibility of millimeter wave radar devices in realistic outdoor environments.