Experimental Study On Broadband Attenuation Characteristics Of Wave-transparent Material For Radome

Broadband electric field probe is an electromagnetic environment measuring device,and it’s core component consists of a sensing antenna and an radome.The wave propagation characteristics of the radome directly affect the overall performance of the field probe,so the study of broadband attenuation characteristics of radome materials has important theoretical and practical value.This article adopts the method of combining theory with practice,analyzing theoretically the broadband attenuation characteristics of radome materials;On the basis of existing testing methods,a broadband attenuation characteristic measurement system is set up,and used to study experimentally the broadband attenuation characteristics of radome materials.The main work of this paper is as follows:Based on the theory of electromagnetic wave propagation in medium,combined with design requirements of radome with broadband electric field probe,the process of the electromagnetic wave penetrating the radome wall is modeled,and carry out the theoretical calculation and analysis by using Matlab software.Then it is mainly discussed that the effect of dielectric constant and loss tangent of radome on wave propagation rate.On this basis,Three typical materials,PC material,PTFE material and EPP material,suitable for broadband electric field probe radome are selected,and by theoretical calculation theoretical results of broadband attenuation characteristics of three typical materials are obtained.A broadband attenuation characteristic measurement system is set up.The system is made up of a signal generator,a transmitting antenna,a broadband electric field probe,a microcomputer and a shielding wall.The signal generator generates an electromagnetic signal,and the electromagnetic wave radiates through the transmitting antenna and penetrates the radome test sample.Then measure the electromagnetic wave signals through the test sample with the broadband electric field probe.By comparing the measured values of the electric field before and after the test panel with or without radome,the penetration rate of the sample is obtained.The test system has the advantages of small probe,easy to set up and easy to test.It can be used in field test.Three typical wave transmitting materials of radome are tested experimentally.And the result shows that the wave penetration rate of materials varies with the frequency of electromagnetic waves,and under the condition of 1~40GHz frequency band and electromagnetic wave vertical incidence,the range of transmissivity in PC material is 73.39%~99.93%,and the range of transmissivity in PTFE material is 84.21%~99.91%,and the range of transmissivity in EPP material is 96.68%~99.99%.According to the design requirements of radome for broadband electric field probe radome,when only transmissivity is considered,EPP material is superior to the other two materials;Considering both transmissivity and strength,PC materials and PTFE materials meet demand.