Intrusion detector
First Claim
Patent Images
1. An intrusion detector comprising:
- (a) a pair of spaced leaky coaxial cables,(b) at least one pollable terminal connected to first adjacent ends of the cables, for receiving and/or transmitting digital data signals along one or both of said cables,(c) control means connected to the other adjacent ends of the cables for polling said terminal or terminals and for transmitting to and/or receiving digital data signals from the terminal or terminals along one or both of said cables,(d) means for applying a CW radio frequency signal to one of said cables,(e) means for receiving the radio frequency signal from the other of the cables, and(f) means for detecting predetermined variation in the received signal from said other cable,whereby the approach of a body to the vicinity of said cables causing said variation in the received radio frequency signal can be determined, thereby providing warning of a possible threat to the transmission of said data signals.
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Accused Products
Abstract
This invention is an intrusion detector which uses codirectionally coupled CW leakly cable sensor techniques. Successive sensors are connected serially through R.F. decouplers, and each is polled and is sent power from a control unit via the serial cables, through the decouplers. The detector thus provides both intrusion detection and a secure data link.
46 Citations
25 Claims
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1. An intrusion detector comprising:
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(a) a pair of spaced leaky coaxial cables, (b) at least one pollable terminal connected to first adjacent ends of the cables, for receiving and/or transmitting digital data signals along one or both of said cables, (c) control means connected to the other adjacent ends of the cables for polling said terminal or terminals and for transmitting to and/or receiving digital data signals from the terminal or terminals along one or both of said cables, (d) means for applying a CW radio frequency signal to one of said cables, (e) means for receiving the radio frequency signal from the other of the cables, and (f) means for detecting predetermined variation in the received signal from said other cable, whereby the approach of a body to the vicinity of said cables causing said variation in the received radio frequency signal can be determined, thereby providing warning of a possible threat to the transmission of said data signals. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. An intrusion detector comprising:
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(a) a control unit, (b) a plurality of remote terminals spaced along a line to be protected, each of said terminals including a radio frequency transmitter and receiver, (c) a pair of coupled leaky coaxial cable means associated with each terminal, one connected to the transmitter and one connected to the receiver, (d) means at each terminal for detecting a predetermined variation in a transmitted signal received at the receiver via the cable means caused by the intrusion of a body adjacent the cable means changing the coupling therebetween, and for generating an intrusion detection signal in response thereto, each said receiver, transmitter and pair of cable means forming a sector intrusion detector, (e) means for connecting the cable means serially at each of said terminals, between each of the sector detectors, and to the control unit along said line to be protected, said connecting means including radio frequency decoupling means, (f) means for receiving a data signal from the control unit via the cable means and decoupling means, which signal includes a remote terminal address, and (g) means at each remote terminal for detecting a predetermined remote terminal address and for applying the intrusion detection signal to the cable means for passage through said decoupling means and reception by the control unit upon said address matching said predetermined address. - View Dependent Claims (13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 24)
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23. An intrusion detector comprising:
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(a) serially connected CW type leaky coaxial cable intrusion detectors comprising pairs of parallel, buried leaky coaxial cables, the cables of each detector being connected to but isolated from those of an adjacent detector by RF decoupling means, each detector having a centrally connected control terminal, (b) a control unit connected to the serial intrusion detectors through RF decoupling means, (c) said control unit including means for applying alternating pulses of power to the leaky coaxial cable of said detectors at a frequency different from a submultiple of standard power mains frequency, (d) means at each control terminal for rectifying said power to obtain DC operating power thereby, and (e) means at each control terminal for receiving an address signal from the coaxial cable applied thereto by the control unit, and for applying an intrusion signal to the coaxial cable following detection of a predetermined address signal unique to each control terminal, in the event of detection of an intrusion by the addressed detector.
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25. An intrusion detector comprising:
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(a) serially connected leaky coaxial cable intrusion detectors, each connected to but isolated from an adjacent detector by RF decoupling means, each detector having a centrally connected pollable control terminal, (b) a control unit connected to one end of the serial intrusion detectors through RF decoupling means including means for polling each control terminal, (c) means for transmission of intrusion signals from each control terminal to the control unit via the coaxial cable through the RF decoupling means, and (d) means for transmitting and receiving digital data signals along said coaxial cable through the decoupling means upon polling by the control unit, to form an intruder-secure data link.
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Specification