Wireless communication system
First Claim
1. A communications system comprising:
- a transmitter arranged to transmit bursts of RF energy at a regular period;
a communication unit having an antenna through which RF energy is received from the transmitter, a control element having one or more states, and an electrical circuit for generating, controlling the period of, and transmitting a pulsed RF output signal from the communications unit in dependence on the state of the control element, through a second antenna; and
a receiving communications unit having a receiver for receiving the pulsed RF signal from the communications unit, and including an electrical circuit for detecting, as a parameter of the pulsed RF signal, the time of receipt of the pulsed RF output signal, determining if a change in the period of receipt of the responses occurs and, if so, generating an output control signal dependent on the change in the period of receipt of the pulsed RF signal.
1 Assignment
0 Petitions
Accused Products
Abstract
An RFID tag (200) and similar control/sensing unit (300) for a communications system are described. The control/sensing unit has a control element (301) having one or more states, and include an antenna (207) as well as an electrical circuit (201-206) generating a pulse control signal for controlling transmission from the antenna and varying a parameter of the pulse control signal in dependence on the state of the control element (301). Also disclosed is a receiving communication unit in the form of a base unit or system controller for such a communications system, the unit including a receiver (100) for receiving a pulsed RF signal and an electrical circuit (105-106) for detecting a parameter of the pulsed RF signal. An output circuit (107) then produces an output control signal dependent on the detected parameter of the pulsed RF signal.
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Citations
37 Claims
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1. A communications system comprising:
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a transmitter arranged to transmit bursts of RF energy at a regular period; a communication unit having an antenna through which RF energy is received from the transmitter, a control element having one or more states, and an electrical circuit for generating, controlling the period of, and transmitting a pulsed RF output signal from the communications unit in dependence on the state of the control element, through a second antenna; and a receiving communications unit having a receiver for receiving the pulsed RF signal from the communications unit, and including an electrical circuit for detecting, as a parameter of the pulsed RF signal, the time of receipt of the pulsed RF output signal, determining if a change in the period of receipt of the responses occurs and, if so, generating an output control signal dependent on the change in the period of receipt of the pulsed RF signal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29)
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30. A communications system having
a transmitter arranged to transmit bursts of RF energy at a regular period; -
a communications unit having an antenna through which RF energy is received from the transmitter, storage means for storing the energy, an electrical circuit for generating output responses at a period dependent on the amount of energy stored and transmitting the output responses; and a receiving communications unit having an electrical circuit for receiving the output responses from the communications unit and for detecting the time of receipt of the output responses, determining if a change in the period of receipt of the responses occurs and, if so, generating an output. - View Dependent Claims (31, 32, 33, 34, 35, 36, 37)
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Specification