| 摘要 |
PURPOSE:To always ensure an automatic reception in the optimum direction, by giving the electrical control to the directivity of the anttenna sevice consisting of the dipole antennas. CONSTITUTION:Folded and abbreviated dipole antennas 31-34 possessing the distribution constant inductance are connected to compounding units 35 and 37 via phase shifters 41-44 respectively and then to compounding unit 39 via switching means 47. Each phase shifter is connected via switching means 46 to control means 45 which delivers two different phase control signals. The receiver connected to such antenna device detects the amplitude of the intermediate frequency signal. And switching means 46 and 47 are controlled in order to secure the maximum detection signal. Thus the directivity can be controlled for the antenna device. In such way, an automatic reception is alwasy possible in the optimum direction, at the same time attaining the miniaturization of the antenna device. |
