| 摘要 |
An antenna for reception and transmission of a radar, which allows the use of low-frequency pulses despite a limit in the area for mounting antenna and enables the maximum range of distance to be extended. When the area for mounting antenna is limited, an antenna shorter than a required one must be mounted, thus reducing the efficiency. Therefore, the ends of a transmitting antenna (11) and ends of a receiving antenna (12) of a dipole antenna unit (1) are bent according to this invention. The effective length of the antenna is nearly one half ( lambda /2) of the wavelength of transmitted electromagnetic waves. The antenna can be mounted on an underground radar for surveying underground or a radar which is used in connection with underground construction machinery so as to survey the terrain around the site. |
