| 摘要 |
<p>A directionality switching antenna apparatus of the present invention is provided with radiator 102 in folded form, folded at a length of predetermined length from a feeding point of ground plane 101, with one end thereof connected to the feeding and with the other end thereof shorted with ground plane 101, a plurality of parasitic elements 103 spaced in the vicinity of radiator 102 each with an element length set to provide the parasitic elements with an electrically symmetrical relation to the center axis of radiator 102, inductors 104 loaded on respective parasitic elements 103, diodes 105 connected to ground plane 101, switching elements 106 that connects in parallel respective inductors 104 and respective diodes 105 between respective parasitic elements 103 and ground plane 101. In this way, even when positions of antenna elements become physically asymmetrical with respect to the axis of the radiator, the antenna elements are in electrically symmetrical relation, whereby it is possible to obtain equal radiation characteristics in each radiation direction.</p> |
