| 摘要 |
PROBLEM TO BE SOLVED: To provide an antenna system with which directivity can be variably controlled corresponding to mechanical displacement by variably controlling the directivity corresponding to an apex angle formed by an inverted V-shaped loop path with a reception frequency. SOLUTION: This antenna system 1 is provided with a loop path for which a conductor D to become a prescribed effective electric length corresponding to the reception frequency is folded into inverted V shape. The inverted V-shaped loop path is formed by successively folding the conductor D from an power feeding point F to nodes 1a-1e. In such a form, vertical angleαfacing the power feeding point F, hypotenuse L1 forming the vertical angleα, short line L2 and conductor D diameterϕbecome parameters to decide antenna characteristics. In this case, when azimuth angles 0 deg., 90 deg., 180 deg. and 270 deg. in directional patterns are respectively defined as south, east, north and west, a main robe is generated in the east-west direction concerning the direction pattern for which the length of the oblique line L1 is 0.5λand the apex angel is from 30 deg. to 60 deg.. On the contrary, in the directional pattern for which the vertical angle 90 deg., the main robe is changed into south-north direction.
|
