| 摘要 |
PROBLEM TO BE SOLVED: To provide a radiation pattern variable antenna device at low cost.SOLUTION: The antenna device comprises a finite ground plate, a power feeding point, a plurality of power feeding antenna elements, a changeover switch and a plurality of non-power feeding elements. The power feeding point is arranged in the finite ground plate. The plurality of power feeding antenna elements are arranged radially toward the power feeding point at a predetermined height from the finite ground plate. The changeover switch connects one end of an element selected from the plurality of power feeding antenna elements to the power feeding point. The plurality of non-power feeding elements are arranged respectively corresponding to the power feeding antenna elements, one ends of which are connected to the finite ground plate and the other ends of which are capacitively coupled to the other ends of the power feeding antenna elements. The non-power feeding elements have length comparable to wavelength of nearly a quarter of a radio frequency to be used. Distance between the other ends of the power feeding antenna elements and the power feeding point are shorter than the non-power feeding elements. |
