| 摘要 |
PROBLEM TO BE SOLVED: To prevent the influence of multipath or the like even if a radio wave is received while the vehicle is moving. SOLUTION: A plurality of antennas 1, 2, 3, and 4 are installed at a windshield 12 and rear glass of a body 9, thus complementing directivity within a horizontal surface. Since a radio wave is received by an antenna 1, 2, 3, or 4 selected by a diversity circuit 18, the gain is reduced and influence is avoided even if the radio wave arrives from a direction different from the direction of a target radio wave due to multipath. In the antennas 1, 2, 3, and 4, metal of a roof section 11 of the body 9, pillar sections 14 and 17, or the like is utilized as a reflector, thus obtaining directivity as indicated by beams 1a, 2a, 3a, and 4a.
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