Thin wave absorber based on rubber sheet combined with flaky magnetic powder for electronic toll collection

Abstract
A thin wave absorber based on ethylene-propylene-diene methylene rubber sheet combined with flaky magnetic powder is examined at 5.8 GHz in electronic toll collection (ETC) system. As a result, the matching frequency is shifted to 5.94 GHz because of the difference between the thickness of a designed value and a fabricated value; however, it is confirmed that the absorption of 25 dB or more can be obtained at the incident angle ranging from 5° to 45° for circularly polarized waves used as means of communications in ETC systems. Therefore, the thin wave absorber based on rubber sheet satisfying commercial requirements of ETC can be realized when the thickness of the absorber is controlled. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 2065–2067, 2006; Published online in Wiley Inter-Science (www.interscience.wiley.com). DOI 10.1002/mop.21851