PURPOSE: To quickly detect the coming direction of radio waves with limited processing circuits by calculating the angle of the coming beam direction in the combination of received signals with two linear antenna arrays to control the direction of a pencil beam in a flat array antenna.
CONSTITUTION: The conic angles of a cone with axes of arrays A and B and the coming direction of radio waves as generating lines is determined with angle computation circuits 3a and 3b through Fourier transform or the like of received signals with linear antennas A and B and cmbined with a direction detecting circuit 4 to calculate the coming directions of radio waves. A phase shifter 2 is controlled through a excitation distribution computing circuit 5 and a control circuit 6 so that the direction of a pencil beam outputted from a flat antenna array C corresponds to the direction calculated with the circuit 4. A judging circuit 8 decides on the true coming direction dependent on the reception of the beam. With such an arrangement, the coming direction of radio waves can be detected quickly with limited processing circuits.
MANO SEIJI
CHIBA ISAMU
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