| 摘要 |
PURPOSE:To remove an undesired radio wave of the same frequency with a desired signal by making the null direction of the directivity of an antenna coincide with the arrival direction of a radio wave received by an array antenna. CONSTITUTION:Since the polarized wave of desired signal is made to coincide with the plane of polarization of antenna 1, desired signal 11 is not received by antenna 2 having the plane of polarization orthogonal to that of antenna 1. Antenna 2, on the other hand, receives only undesired radio wave 12. Therefore, the arrival direction of a radio wave detected by the detecting circuit for undesired-radio-wave arrival- direction 4 coincides with that of an undesired radio wave. A control signal for directing the null direction of the directivity of antenna 1 to the undesired-radio- wave arrival direction detected by this circuit 4 is outputted by generating circuit 5 for control, so that antenna 1 will never receive undesired radio wave 12. |
