| 摘要 |
<p>An antenna device (100; 100A) is provided which is capable of dealing with two or more frequencies or of carrying out communications using two or more communication methods by a single antenna and of controlling its directivity and, therefore, of achieving improvements in communication performance of the antenna device (100; 100A). The antenna device (100; 100A) is so constructed that its shape is freely changed and its directivity can be changed to deal with a signal in any frequency band. The antenna device (100; 100A) is made up of two or more antenna elements (1) and switches (2) which put each of the antenna elements (1) into a connected or disconnected state. By controlling the switches (2), a shape of the antenna (10) is changed so as to have a 90-degree bent dipole configuration to provide directivity, and a length of the antenna is changed so as to allow a changeover of a frequency band. The antenna device (100; 100A) has a reflector (20) being similar to the dipole-type antenna, which enables improvements in its directivity. <IMAGE></p> |
