The Evaluation Method Of Rf Noise Suppression Sheet And The Measurment Technique Of The Dielectric Properies Of Dielectric Material By Open-Coaxial Probe Method

Microwave dielectric material has been widely used in aerospace,microwave communication.stealth technology,biological medicine,electromagnetic compatibility and so on.There are need to test the electromagnetic characteristic parameters in the research and development,production and use of microwave dielectric materials.This topic focuses on the electromagnetic properties of microwave dielectric material parameters, such as intra-decoupling,inter-decoupling,transmission attenuation power ratio and complex permittivity test system and test methods.The main contents are:(1)According to the standard IEC62333-2 ?Noise suppression sheet for digital devices and equipment-part 2:Measuring methods?,tested the intra-decoupling and inter-decoupling of the noise suppression sheet in 100MHz?6GHz, to provide the evaluation method of noise suppression performance.Firstly,with the aid of the electromagnetic simulation software CST to established the loop antenna model,stimulated the transmission characteristics of S21 without noise suppression sheet and with noise suppression sheet above the loop antenna 3mm and in the middle of loop antenna.Secondly, loop antenna fabricated by semi-rigid cable,measured the transmission characteristics of S21 without noise suppression sheet and with noise suppression sheet above the loop antenna 3mm and in the middle of loop antenna.Thirdly,compared the result of simulation and measured, the finding show that the result of simulation and measured are consistent with each other, this device can be used to evaluate the noise suppression performance of noise suppression sheet in 100MHz?6GHz.(2)According to the standard IEC62333-2 ?Noise suppression sheet for digital devices and equipment-part 2:Measuring methods?,tested the transmission attenuation power ratio of the noise suppression sheet in 30MHz?10GHz, to provide the evaluation method of noise suppression performance.Firstly,with the aid of the electromagnetic simulation software CST to established the microstrip line model,stimulated the return loss of S11 and the transmission characteristics of S21 without noise suppression sheet and with noise suppression sheet.Secondly,fabricated microstrip line model, measured the return loss of S11 and the transmission characteristics of S21 with noise suppression sheet and with noise suppression sheet.Thirdly,compared the result of simulation and measured, the finding show that the result of simulation and measured are consistent with each other, this device can be used to evaluate the suppression performance of electromagnetic interference of noise suppression sheet in 30MHz?10GHz.(3)Measurement of complex permittivity of non magnetic materials using an open-ended coaxial probe method.First of all, building the theoretic modeling for opened coaxial method by using the Electromagnetic field method,and the functional relationship between the complex reflection coefficient and complex permittivity could be established;therefore,we can find the reflection coefficient theoretical value of the sample material.After that,conducting simulations by using the electromagnetic simulation software CST,obtain the corresponding reflection coefficient of the simulation value.Finally,measuring the reflection coefficient values of the dielectric materials by using the vector analyzer to get the actual results of reflection coefficient.For the same kind of material, compare the theoretical value,simulation value and the measured value,we found those three values matches very well,and it verifies the correctness of this modeling theory.In this paper,the test and uncertainty analysis of the commonly dielectric materials used in 100MHz?6GHz,such as wood,organic glass and ceramic composite material,which are commonly used in engineering,are carried out by using open-ended coaxial probe.