DIRECTIVITY CONTROL DEVICE

摘要

PROBLEM TO BE SOLVED: To control a directivity control device in response to environmental characteristics such as density of high-rise buildings. SOLUTION: The directivity control device 106 switches or synthesizes received signals by two antennas A1 and A2 with a switch 110 or a synthesizer 120. The elevation angle of the antennas A1 and A2 are directly switched by elevation angle switching devices A1C and A2C separately. When a ratio of height H of a building to road width W is larger than a first threshold Hth1and a position of transmitting point is in the right or left region, a directivity of the directive antenna 1 is controlled to have a high elevation angle to be perpendicular to the road leftward or rightward. In other cases, the directivity is a low elevation angle and is horizontally changed by electric wave's arrival angle. In suburbs, the directivity is controlled to be a low elevation angle in the direction of transmitting point. COPYRIGHT: (C)2006,JPO&NCIPI