| 摘要 |
PROBLEM TO BE SOLVED: To provide a flat antenna device capable of taking measures against snowfall and rainfall as the existing conventional shape of antenna without adding a special structure. SOLUTION: A flat antenna having a plurality of antenna elements is mounted on a supporting member in a way that the direction crossing an opened face of the flat antenna is made equal to a depression angle.Even when the flat antenna is made slanted mechanically, it is equivalent to a case of setting eaves. The slanted factor of the flat antenna in the maximum radiation direction is compensated by an electric tilt. Namely, by advancing a phase of exciting power fed to a lower antenna element out of the antenna elements more than the exciting power (or exciting current) fed to an upper antenna out of the antenna elements, the radiation maximum direction is turned up more than the depression angle, so the maximum radiation direction of the flat antenna can be made equal to the desired direction. COPYRIGHT: (C)2005,JPO&NCIPI
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