| 摘要 |
PURPOSE:To improve performance and to reduce cost by causing two walls, which are faced each other, to be unparallel in a direction, in which a propagating shaft passes through, and obtaining the two parts of different ceiling height and the third part of an oblique ceiling between the two parts. CONSTITUTION:The ceiling is divided into three parts and the parts are defines as two ceilings 11 and 12 of the different ceiling height and an oblique ceiling 13 between these two ceilings 11 and 12. Accordingly, a horizontally polarized wave from a transmission antenna is reflected by the third oblique part 13 of the ceiling and an area, in which a reflected wave does not exist, is obtained. Then, a reception antenna is set in this area so that the reflected wave from the ceiling can not hit the reception antenna. Concerning a vertically polarized wave from the transmission antenna, the wave is reflected by two walls 11 and 12 to be faced each other in the direction, in which the propagating shaft of the wave passes through between the transmission antenna and reception antenna, and to be unparallel. However, the wave from the transmission antenna and the reflected wave from the wall are not canceled. Thus, an attenuating area is not generated in electro-magnetic field distribution around the reception antenna and an electric wave absorber with high reflection attenuation performance is eliminated. |
