Communication system for vehicles
First Claim
1. A communication system for vehicles, said system comprising:
- an antenna unit disposed over a road for setting a communication area by operating at a specified oscillation frequency;
an antenna element provided within the antenna unit, said antenna element including a center patch and an end patch, a transmission line connecting the center patch and the end patch and a power supply terminal connected to the transmission line, an impedance of said end patch as seen from said power supply terminal being higher than an impedance of said center patch as seen from said power supply terminal, for sending an interrogatory signal to a vehicle; and
a communication controlling means provided within the antenna unit for controlling transmission and receipt of signals at the antenna unit.
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Accused Products
Abstract
A communication system for vehicles, which obtains exact communication processing with responders mounted on vehicles running on a road having a plurality of traffic lanes, is disclosed. An expressway has three traffic lanes. A gantry is disposed in a specified position on the expressway. On the gantry are disposed antenna units to counter the traffic lanes respectively. The antenna units are provided with communication areas by means of a pair of antenna elements respectively. The antenna element is composed of a microstrip array antenna disposed with eight pieces of patches laid out in two rows with four pieces in each row. The antenna units controls communication processing to communicate with vehicles adjoining each other. When response signals are sent from a vehicle mounted responder, the vehicle mounted responder is fixed and communication processing for toll collection is performed. As a result, communication processing with responders mounted on vehicles respectively which are running in the respective traffic lanes can exactly be performed.
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Citations
21 Claims
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1. A communication system for vehicles, said system comprising:
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an antenna unit disposed over a road for setting a communication area by operating at a specified oscillation frequency; an antenna element provided within the antenna unit, said antenna element including a center patch and an end patch, a transmission line connecting the center patch and the end patch and a power supply terminal connected to the transmission line, an impedance of said end patch as seen from said power supply terminal being higher than an impedance of said center patch as seen from said power supply terminal, for sending an interrogatory signal to a vehicle; and a communication controlling means provided within the antenna unit for controlling transmission and receipt of signals at the antenna unit. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18)
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19. A communication system for vehicles, said system comprising:
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an antenna unit disposed over a road for setting a communication area by operating at a specified oscillation frequency; an antenna element provided within the antenna unit, said antenna element including a center patch and an end patch, a transmission line connecting the center patch and the end patch and a power supply terminal connected to the transmission line, an impedance of said end patch as seen from said power supply terminal being different from an impedance of said center patch as seen from said power supply terminal, for sending an interrogatory signal to a vehicle, a portion of said interrogatory signal sent from said center patch being greater than a portion of said interrogatory signal sent from said end patch; a communication controlling means provided within the antenna unit for controlling transmission and receipt of signals at the antenna unit; wherein a communication area covered by said antenna unit includes a main lobe disposed at a position to be communicable with said vehicle and a side lobe disposed at a position where it is not communicable with said vehicle. - View Dependent Claims (20, 21)
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Specification