| 摘要 |
PCT No. PCT/SE93/00969 Sec. 371 Date May 23, 1995 Sec. 102(e) Date May 23, 1995 PCT Filed Nov. 15, 1993 PCT Pub. No. WO94/13030 PCT Pub. Date Jun. 9, 1994A Y-Antenna which includes an elongate Y-shaped metal portion and a bottom plate of metal which is mounted beneath and substantially at right angles to the vertical shank of the Y-shaped metal portion and is galvanically connected to this shank. The Y-shaped metal structure includes two preferably parallel notches, quarter wave resonant on different frequencies and preferably open at one short end and which are electromagnetically coupled to one another. The two parallel notches are disposed in the V-shaped shanks of the Y and, in one preferred embodiment, have a common side which consists of the upper edge of the vertical portion of the Y. In one preferred embodiment, only one of the notches is directly fed with energy. The antenna gain and the bandwidth of the antenna can be increased with the aid of an extra metal screen in the form of a shank which is galvanically connected to the short-circuited short end of the directly fed V-shank, whereafter the extra shank is bent so that it covers approximately 70% of the upwardly directed longitudinal aperture of the V-shanks. A further increase of the bandwidth can be obtained in that upper edges of the shanks are provided with rectangular sheet flarings. |
