| 摘要 |
PURPOSE:To calibrate a vehicle position with high accuracy by providing an on-vehicle antenna directivity in breadthwise directions of a vehicle to a vertical polarized signal from a roadside antenna and in lengthwise directions of the vehicle to a horizontal polarized signal. CONSTITUTION:The on-vehicle antenna 7 and a hybrid circuit 11 are used and both feed points 5 and 6 of the antenna 7 are fitted at right angles to the traveling direction of the vehicle. Then a vertical polarized radio wave is radiated from the roadside antenna and its received signal is led out through the opposite-phase side terminal 15 of the circuit 11 to obtain the high reception directivity to the vertical polarized radio wave arriving in the direction perpendicular to the traveling direction of the vehicle. For the purpose, only this vertical polarized radio wave is used for navigation and navigation data is accurately calibrated. Further, the horizontal polarized radio wave is radiated from the roadside antenna, the feed points 5 and 6 are fitted in the traveling direction of the vehicle, and a received signal is led out through the terminal 15 as well as the vertical polarized wave, thereby obtaining the high reception directivity to the horizontal polarized radio wave in the direction perpendicular to the vehicle traveling direction.
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