| 摘要 |
<p>PURPOSE:To operate the underground radar in various underground soil states and to make an accurate survey of any soil by switching the antenna size to >=2 kinds corresponding to the conditions of the ground surface and the wavelength of an electromagnetic wave in use. CONSTITUTION:A basic dipole antenna 31 which is fixed is provided with auxiliary antennas 31a and 31b which are coupled with it. The auxiliary antennas 31a and 31b are supported on a column made of ceramic, etc., which is not affected by the radiation characteristics of the electromagnetic wave. The column 34 is coupled with a moving mechanism 33, which is driven by a motor 37 through a nut 36 and a ball screw 35. Then when a driving signal is sent out of an antenna control circuit, the auxiliary antenna 31a or 31b coupled with the moving mechanism 33 moves in a commanded direction and is coupled with the antenna 31. The radar has the shortest adaptive wavelength when only the antenna 31 is used, long adaptive wavelength when the auxiliary antenna 31 is coupled, and the longest adaptive wavelength when the auxiliary antenna 31b is coupled.</p> |
