Characterization And Measurement Technology For The Microwave Electromagnetic Parameters Of Conductive Electromagnetic Fiber

Carbon fiber composites absorbing materials have the function of bearing and reducing radar reflectivity of cross section, and have been widely used in stealth weapons. However, anisotropic electromagnetic materials performance development and application design have been hindered by the characterization and measurement of electromagnetic parameters of fiber electromagnetic materials. Therefore, there is an urgent need to solve the problem of characterization of microwave electromagnetic parameters and electromagnetic wave propagation characteristics of anisotropic electromagnetic materials.Firstly, the theoretical expression for anisotropic electromagnetic parameters of conductive electromagnetic fiber was derived, and the waveguide transmission/reflection method was determined to as the test method for electromagnetic parameters in this article. Combined with the actual needs of the subject, and based on PNA-L N5230A vector network analysis instrument, we built a set of X-band electromagnetic parameters variable temperature test system which constituted by the variable temperature waveguide test blocks, temperature control system, TRL calibration parts and other microwave components, this system can implement the measurement for electromagnetic parameters of the material from room temperature to800℃temperature range, and we can get the test scope for electromagnetic parameters and the test error by analyzing the testing process error sources. Secondly, a set of variable temperature test platform based on the arch method is designed, which is available for the reflectivity test in the1-40GHz frequency range from room temperature to1000℃, with good reliability.In addition, using waveguide method and coaxial line method test the electromagnetic parameters of directional arrangement carbon fiber, and test the microwave reflectivity of directional arrangement carbon fiber by arch method, test results show that the numerical size of measured axial and radial parameters are obviously different, which verified a fact, that is the electromagnetic parameters of carbon fiber is indeed exist anisotropy.