| 摘要 |
PURPOSE:To prevent a primary reflected wave from returning to a receiving antenna by a method wherein a housing space is composed of walls made of metallic material and at least one wall is inclined against the received polarization reference line. CONSTITUTION:A housing space 17 is composed of a floor wall 11, a ceiling wall, a front wall 12, a rear wall 13, a left wall 14 and a right wall 15 made of metallic material. A transmission source 21 and a receiving antenna 22 are provided in the space 17 so as to be vertical to the floor wall 11. In this case, if all the side walls 12-15 are vertical, the direct vertical polarization from the transmission source 21 and the vertical polarization of the primary reflection produced by the side walls 12-15 are received by the antenna 22. If one of the side walls 12-15 is inclined, the magnitude of the wave received by the antenna 22 is varied and the primary reflected wave can be so controlled as not to return to the antenna 22. When the horizontal polarization is measured, the ceiling wall is inclined. Thus, the reflected wave is not received by the antenna 22 if the walls of the space 17 are properly inclined and, moreover, the space 17 is protected from external radio waves by the metallic walls. As a result, the measurement accuracy of the generated radio wave can be optimized. |
