Set of transmit/receive antennas situated at a fixed station for a two-way radio link with a vehicle

• US 4,806,943 A
• Filed: 11/24/1987
• Issued: 02/21/1989
• Est. Priority Date: 11/25/1986
• Status: Expired due to Fees

• Current Assignee: Compagnie Generale D'Electricite
• Original Assignee: Companie Generale D'Automatisme
• Inventors: Doncel, Miguel
• Primary Examiner(s): Sikes, William L.
• Assistant Examiner(s): LE, HOANGANH T
• Application Number:
  US07/124,523
• Time in Patent Office: 455 Days
• Field of Search: 343/742, 343/711, 343/713, 343/717, 343/866, 343/867, 343/873, 455/99, 455/129, 455/272, 455/274, 340/941
• US Class Current: 343/742
• CPC Class Codes: G07C 9/28 the pass enabling tracking or indicating presence
• CPC Class Codes: G08G 1/015 with provision for distinguishing between two or more types of vehicles, e.g. between motor-cars and cycles
• CPC Class Codes: G08G 1/042 using inductive or magnetic detectors
• CPC Class Codes: G08G 1/096716 where the received information does not generate an automatic action on the vehicle control
• CPC Class Codes: G08G 1/096758 where no selection takes place on the transmitted or the received information
• CPC Class Codes: G08G 1/096783 where the origin of the information is a roadside individual element
• CPC Class Codes: H01Q 1/3225 Cooperation with the rails or the road

Abstract

In a fixed station for a two-way radio link with a vehicle (5) which has a self-contained transmit/receive device (6) including a transmit antenna (8) in the form of a vertical axis coil so as to generate a vertical electromagnetic field and a receive antenna (9) in the form of a horizontal axis coil disposed transversely relative to the vehicle, a set of transmit/receive antennas at the fixed station includes a receive antenna constituted by a first multiconductor cable (10) forming a rectangular loop whose long dimension runs parallel to the direction of vehicle displacement, and a transmit antenna constituted by a second multiconductor cable (12) forming two narrow elongate rectangular loops extending in the direction of vehicle displacement and mutually parallel so as to create a horizontal electromagnetic field extending perpendicularly to the direction of vehicle displacement. The first and second cables are placed in slots (11) formed in the roadway where the vehicle passes, and subsequently closed by suitable material (18). The ends (13, 14, 15, and 16) of the two cables are brought together to the side of the roadway (1) in a junction box (17) for enabling various connections to be performed, the junction box also receiving two screened cables, one of which serves to feed the transmit antenna, and the other of which serves to receive current picked up by the receive antenna.

Claims

1. a set of transmit/receive antennas situated at a fixed station for a two-way radio link with a vehicle, said vehicle being provided with a self-contained transmitter/receiver device fixed to the bottom of the vehicle and including a transmit antenna in the form of a vertical axis coil so as to generate a vertical electromagnetic field and a receive antenna in the form of a horizontal axis coil disposed transversely relative to the vehicle, wherein the set of transmit/receive antennas at the fixed station comprises a receive antenna constituted by a first cable comprising a first plurality of conductors and a rectangular loop whose long dimension runs parallel to the direction of vehicle displacement, and a transmit antenna constituted by a second cable comprising a second plurality of conductors and forming two narrow elongate rectangular loops parallel to each other and extending in the direction of vehicle displacement so as to create a horizontal electromagnetic field extending perpendicularly to the direction of vehicle displacement, said first and second cables being placed in slots formed in the roadway where the vehicle passes, and subsequently closed;

the ends of the two cables being brought together to the side of the roadway in a junction box for enabling various connections to be performed, said junction box also receiving two screened cables, one of which serves to receive current picked up by the receive antenna.