Claims
- 1. A roadside beacon system, comprising:
- means for transmitting data to a plurality of vehicles on roads including a plurality of transmitting antennas located along side respective ones of said roads, each transmitting antenna being located at a height above said respective vehicles and having a propagation directivity pattern directed obliquely downwards; and
- mobile antenna mounted on each of said vehicles for receiving said transmitted data, each mobile antenna having a reception directivity pattern directed upwardly, wherein the reception of said mobile antennas is strongest in an upward direction.
- 2. A roadside beacon system as recited in claim 1, wherein said reception directivity pattern is directed obliquely upwardly toward both lateral sides of said each vehicle.
- 3. A roadside beacon system as recited in claim 1, wherein said propagation directivity pattern has a perpendicular to a principal direction of said respective road and passing through said antenna.
- 4. A roadside beacon system as recited in claim 2, wherein said propagation directivity pattern has a maximum directivity in a vertical plane passing perpendicular to a principal direction of said respective road and passing through said antenna.
Priority Claims (1)
Number |
Date |
Country |
Kind |
61-57370 |
Mar 1986 |
JPX |
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Parent Case Info
This is a continuation, of application Ser. No. 026,359, filed Mar. 16, 1987 now abandoned.
US Referenced Citations (5)
Foreign Referenced Citations (7)
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EPX |
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Jan 1981 |
JPX |
229799 |
Nov 1985 |
JPX |
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Nov 1985 |
JPX |
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Nov 1985 |
JPX |
Non-Patent Literature Citations (4)
Entry |
Antennas, Kraus, 1950, pp. 376, 381. |
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Continuations (1)
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Number |
Date |
Country |
Parent |
26359 |
Mar 1987 |
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