| 摘要 |
PURPOSE:To obtain an antenna system and to remove an unnecessary wave for a short time by generating plural antenna beams, forming a zero point for radiation successively in each beam direction and discriminating a beam by receiving arrived radio waves. CONSTITUTION:Plural antenna beams B1, B2- are formed so that a directional zero point is composed in the arriving direction theta3 of a required wave by controlling a phase shifter connected to plural element antennas and only an unnecessary wave is received. A zero point is composed in each beam position; if a receiving level is reduced when a zero point is composed on the position of beam B3, the reception of the unnecessary wave is detected by the beam B3. Subsequently, a difference beam consisting of a monopulse is formed in the arriving direction of the unnecessary wave and the main beam is oriented in the arriving direction of a required wave to obtain a radiation pattern forming a zero point in the arriving direction of the unnecessary wave. |
