Summary
International Symposium on Antennas and Propagation
2008
Session Number:3D09
Session:
Number:3D09-2
Development of Transparent Electromagnetic Wave Absorption Wall
Satoshi SAKAKI, Yoshinobu OKANO,
pp.-
Publication Date:2008/10/27
Online ISSN:2188-5079
Summary:
Recently, the electromagnetic environment is deteriorated because of the emission from wireless equipments. Multi-pass fading and interference in the room are especially serious (see Fig.1) [1]. These phenomena cause deterioration in the wireless communication quality. The use of electromagnetic wave absorption wall (hereafter, it is described as EM-absorption wall) is thought as a suppression technique for these phenomena. As for EM-absorption wall for the room, λ/4 type EM-absorption wall (λ is wave length of the target electromagnetic wave) has been frequently used. Concretely, concentrated area of the microwave is generated by the resonance, and the microwave energy is absorbed with placing the lossy medium in that area. However, thickness of λ/4 type EM-absorption wall depend on wave length of the target electromagnetic wave. Additionally, because EM-absorption wall intercepts light, watching is obstructed. This property obstructs the safety securing and crime prevention. Accordingly, this report is described about the thickness suppression technology and the transparency improvement technology for the EM-absorption wall. 950MHz band used with UHF-RFID system is chosen as a target frequency. Generally, UHF-RFID system is used indoors, and influenced easily by electromagnetic interference. Therefore, EM-absorption wall is necessaries in UHF-RFID system.