Development of Broad-Band Electromagnetic Wave Absorberfor X-band Sensors in Double-layered Type Using Carbon

Abstract

In this paper, the EM wave absorbers were designed and fabricated for X-band sensors using Carbon of dielectric material with CPE. The complex relative permittivity of samples is calculated by using measurement results of S-parameter. We simulated the double-layered type EM wave absorber with broad bandwidth using the measured complex relative permittivity by changing the thickness and layer, which was fabricated based on the simulated design. The fabricated EM wave absorber consists of 1 mm first layer sheet facing metal with Carbon composition ratio 70 vol.% and 1.5 mm second layer sheet with Carbon composition ratio 60 vol.%. The measured results showed a good agreement to the simulated ones. It is found that the optimized absorption ability of double-layered type EM wave absorber with thickness of 2.5 mm is higher than 10 dB from 7.8 GHz to 13.3 GHz.