Measurement and simulation of the shielding effectiveness of materials using the astm d4935 flanged coaxial transmission line

This paper presents an introduction to the application of the shielding effectiveness measurement method, according to the ASTM D4935 standard [1]. Measurements of the shielding effectiveness of a reference material, whose electromagnetic properties are well known, are presented in this paper. In addition, a 3D electromagnetic model of the measurement rig is created and validated. Finally, a finite-integration-technique simulation is performed applying a commercial software package, CST Microwave Studio (CST MWS), on the reference material sample. Despite the upper frequency limitations (due to excitation of higher order modes) and the limitations due to sample thickness and re-reflected signals on the air-material interfaces of the sample, it is shown that a good correlation between simulation, laboratory measurements and expected theoretical values can be obtained. This validation work will serve as the basis for future measurement programs of aerospace type of carbon fibre based composite materials, in the RF frequency range, in which the double flanged coaxial rig defined in ASTM D4935 is used.