Resistive and capacitive modulation in an electromagnetic transponder
First Claim
Patent Images
1. An electromagnetic transponder comprising:
- an oscillating circuit;
an electronic circuit comprising a transmit circuit for transmitting digitally-coded information and a receive circuit adapted to receive, from a terminal, a configuration signal at a start of each communication session between the electromagnetic transponder and the terminal; and
at least one first configurable modulation circuit coupled to the oscillating circuit, the at least one configurable modulation circuit comprising a plurality of circuit elements, the plurality of circuit elements comprising at least one resistive or capacitive modulation element, each circuit element being associated with at least one switch to control a power applied to the circuit element, wherein the configuration signal from the terminal specifies a particular arrangement of switches to control power applied to circuit elements of the at least one first configurable modulation circuit to produce a particular modulation scheme for signals transmitted from the electromagnetic transponder.
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Accused Products
Abstract
The selection of at least one back-modulation element of an electromagnetic transponder from among a plurality of resistive and/or capacitive modulation elements of the load of an oscillating circuit of the transponder, including selecting the modulation element(s) according to a binary message received from a read/write terminal.
24 Citations
23 Claims
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1. An electromagnetic transponder comprising:
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an oscillating circuit; an electronic circuit comprising a transmit circuit for transmitting digitally-coded information and a receive circuit adapted to receive, from a terminal, a configuration signal at a start of each communication session between the electromagnetic transponder and the terminal; and at least one first configurable modulation circuit coupled to the oscillating circuit, the at least one configurable modulation circuit comprising a plurality of circuit elements, the plurality of circuit elements comprising at least one resistive or capacitive modulation element, each circuit element being associated with at least one switch to control a power applied to the circuit element, wherein the configuration signal from the terminal specifies a particular arrangement of switches to control power applied to circuit elements of the at least one first configurable modulation circuit to produce a particular modulation scheme for signals transmitted from the electromagnetic transponder. - View Dependent Claims (2, 3, 4, 5, 6)
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7. A method for selecting at least one back-modulation element of an electromagnetic transponder from among a plurality of resistive and/or capacitive elements for modulating the load of an oscillating circuit of the transponder, the method comprising:
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at a start of each communication session between the electromagnetic transponder and a read/write terminal, selecting the at least one back-modulation element to conduct a signal to the oscillating circuit according to a binary message received from the read/write terminal, the binary message specifying at least one particular back-modulation element of the at least one back-modulation element of the electromagnetic transponder to conduct the signal so as to produce a particular modulation scheme for signals transmitted from the electromagnetic transponder, the at least one back-modulation element comprising at least one resistive or capacitive back-modulation element, each back-modulation element of the at least one back-modulation element being associated with a switch that controls a power applied to the back-modulation element; and controlling a state of switches associated with each of the selected at least one back-modulation element such that the signal is conducted to the oscillating circuit via the selected at least one back-modulation element. - View Dependent Claims (8, 9, 10)
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11. A method of controlling a transponder comprising an oscillating circuit, the method comprising:
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A) receiving at the transponder, at a start of each communication session between the transponder and another communication device, an indicator specifying a particular arrangement of circuit elements of the transponder to produce a particular modulation scheme for signals transmitted from the electromagnetic transponder; B) controlling one or more switches to control a power applied via one or more modulation elements to the oscillating circuit to configure the transponder according to the particular arrangement specified by the indicator, the one or more modulation elements comprising at least one resistive or capacitive modulation element; and C) communicating information at least from the transponder to the other communication device using the oscillating circuit coupled to the one or more modulation elements. - View Dependent Claims (12, 13, 14, 15, 16, 17, 18)
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19. A method of communicating between a terminal and a transponder, the method comprising:
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A) at a start of each communication session between the terminal and the transponder, receiving from the terminal at the transponder an indicator specifying a particular arrangement of circuit elements for the transponder to produce a particular modulation scheme for signals transmitted from the electromagnetic transponder, the particular arrangement of circuit elements for the electromagnetic transponder identifying at least one circuit element by which a signal is to be conducted to generate signals from the electromagnetic transponder, each circuit element of the circuit elements being associated with a switch that controls a power applied to the circuit element; B) configuring the transponder to communicate according to the indicator by controlling a state of switches associated with the at least one circuit element such that a signal is conducted via the at least one circuit element, the at least one circuit element comprising at least one resistive or capacitive modulation element; and C) communicating data from the transponder to the terminal according to the particular modulation scheme. - View Dependent Claims (20, 21, 22, 23)
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Specification