| 摘要 |
PURPOSE:To prevent effectively snow and dust from piling up and to prevent deterioration in directivity by impressing a voltage which has the same polarity with snow and dust which are suspended and fall to a conductor provided near an antenna main body. CONSTITUTION:A probe 28 which discriminates the polarity of falling suspended matter such as snow and a voltage generator 29 which generates a voltage with the same polarity that the probe 28 discriminates are installed atop of a column 27. When it snows, the charge of snow that the probe 28 receive is flowed to the ground through a resistance R and the voltage developed at this time is amplified by an amplifier 31 and its polarity is detected by a sign detector 32; and a voltage with the same sign is generated by a high voltage generator 33 and applied to the conductor 21a of a reflector 21 through a lead line 30. Consequently, reactive force to the snow is generated to prevent snow from piling up on the surface of the reflector 21. |
