| 摘要 |
PURPOSE:To always ensure an automatic reception in the optimum direction by giving the electrical control to the directivity of the antenna device consisting of the dipole antennas. CONSTITUTION:The control signal gives the control to each variable reactance of folded and abbreviated dipole antennas 31-34 possessing the distribution constant inductance. These control signals are applied from control means 41 via switching means 43. At the same time, compounding unit 35 to which antennas 31 and 32 are connected plus compounding unit 37 to which antennas 33 and 34 are connected, are connected to compounding unit 39 via switching means 44 respectively. The receiver connected to such antenna device detects the amplitude of the intermediate frequency signal. And the control is given to switching means 43 and 44 to secure the maximum detection signal. Thus the directivity of the antenna device can be controlled. In such way, an automatic reception is always possible in the optimum direction, at the same time attaining the miniaturization of the antenna device. |
