| 摘要 |
PROBLEM TO BE SOLVED: To make a half value width narrower than a sector division angle even while using an existing polarization diversity technique. SOLUTION: In a polarization diversity antenna 10, as shown in figure 1(b), a cylindrical (or polygonal) metal conductor 16 roughly bisected along a center axis is arranged on the opposite side of a radiation element 12 across a reflector 14 so as to surround the radiation element 12 and the reflector 14 at a roughly fixed distance from a prescribed center point A near the radiation element 12. Just by adding the metal conductor 16 to an existing 120°polarization diversity antenna, the antenna of 120°of the same half value width as the sector division angle for three sectors is easily changed to the antenna of 90°of the half value width optimum for increasing a subscriber capacity. Also, since addition to the polarization diversity antenna in service is also available, service interruption accompanying antenna replacement is evaded, and it is economical since the antenna is reutilized. COPYRIGHT: (C)2007,JPO&INPIT
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