| 摘要 |
An antenna achieves effective diversity reception in even a small sized wireless signal-receiving apparatus, improvement in the sensitivity of the antenna, and implementation of a small size, a lower power consumption, and a low price of the antenna. The antenna has antenna elements that are positioned at a smaller distance apart than a half wavelength of the frequency of a signal to be received, a first transmission line and a second transmission line having a delay circuit with a predetermined electric length, and a changeover switch 13 . The difference of the electric length of a path that passes from one antenna element through one of the transmission lines toward a synthesizer from the electric length of a path that passes from the other antenna element through the other transmission line toward the synthesizer is set so as to become (lambda/2-alpha) or (-lambda/2+alpha). When receiving a signal, the changeover switch changes based on a control signal, so that the directivity of the antenna can vary.
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