PERMEABILITY AND PERMITTIVITY MEASUREMENT AND REFLECTIVITY CALCULATION FOR A MICROWAVE-ABSORBING COMPOSITE-MATERIAL CONTAINING A RESONATOR AND AN ELECTROMAGNETIC LOSS SUBSTANCE

A microwave-absorbing composite material was prepared from an electromagnetic loss substance, a resonator and an epoxy resin. The permeability and permittivity of the composite were measured by the use of an HP8510B microwave vector network analyser. It was found that the material works mainly through the dielectric loss mechanism, the magnetic loss being trival. An equivalent circuit was used to simulate the composite in an electromagnetic field and an impedance analysis carried out. Power reflectivity calculation was performed using a BASIC program. The reflectivity variation with frequency determined by calculation was basically in agreement with that revealed by a frequency scanning experiment performed on an HP8410C network analyser.