Sizing of an electromagnetic transponder system for a dedicated distant coupling operation
First Claim
1. An electromagnetic transponder including a parallel oscillating circuit adapted to being excited by a series oscillating circuit of a read/write terminal when the electromagnetic transponder enters an electromagnetic field of the read/write terminal, wherein components of the parallel oscillating circuit of the electromagnetic transponder are sized so that a distance at which a voltage across the oscillating circuit of the transponder is maximum is greater than a distance at which a coupling coefficient between the oscillating circuit of the transponder and the oscillating circuit of the terminal is maximum.
1 Assignment
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Accused Products
Abstract
A system of contactless electromagnetic transmission between a terminal including a series oscillating circuit for generating an electromagnetic field and a transponder including a parallel oscillating circuit, these oscillating circuits being sized so that the coupling coefficient between them rapidly decreases when the distance separating the transponder from the terminal becomes smaller than a predetermined value.
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Citations
24 Claims
- 1. An electromagnetic transponder including a parallel oscillating circuit adapted to being excited by a series oscillating circuit of a read/write terminal when the electromagnetic transponder enters an electromagnetic field of the read/write terminal, wherein components of the parallel oscillating circuit of the electromagnetic transponder are sized so that a distance at which a voltage across the oscillating circuit of the transponder is maximum is greater than a distance at which a coupling coefficient between the oscillating circuit of the transponder and the oscillating circuit of the terminal is maximum.
- 8. A terminal for generating an electromagnetic field adapted to cooperate with at least one transponder when said at least one transponder enters the electromagnetic field, including a series oscillating circuit for generating the electromagnetic field, the series oscillating circuit being sized so that a distance at which a voltage across an oscillating circuit of the transponder is maximum is greater than a distance at which a coupling coefficient between the oscillating circuit of the transponder and the series oscillating circuit of the terminal is maximum.
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13. A system for contactless electromagnetic transmission between a terminal and a transponder, comprising:
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the terminal having a first oscillating circuit including a first resistor a first capacitor and a first inductor; and
the transponder having a second oscillating circuit including a second resistor, a second capacitor and a second inductor;
wherein at least one of the terminal and the transponder is structurally dedicated to operation where a distance between the terminal and the transponder exceeds a predetermined distance;
wherein the first resistor, the first capacitor and the first inductor are sized so that a distance at which a voltage across the second oscillating circuit is maximum is greater than a distance at which a coupling coefficient between the first and second oscillating circuits is maximum. - View Dependent Claims (14, 15, 16)
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17. A system for contactless electromagnetic transmission between a terminal and a transponder, comprising:
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the terminal having a first oscillating circuit including a first resistor, a first capacitor and a first inductor; and
the transponder having a second oscillating circuit including a second resistor, a second capacitor and a second inductor;
wherein at least one of the terminal and the transponder is structurally dedicated to operation where a distance between the terminal and the transponder exceeds a predetermined distance;
wherein the second resistor, the second capacitor and the second inductor are sized so that a distance at which a voltage across the second oscillating circuit is maximum is greater than a distance at which a coupling coefficient between the first and second oscillating circuits is maximum. - View Dependent Claims (18, 19, 20)
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21. A system for contactless electromagnetic transmission between a terminal and a transponder, comprising:
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the terminal having a first oscillating circuit including a first resistor, a first capacitor and a first inductor; and
the transponder having a second oscillating circuit including a second resistor, a second capacitor and a second inductor;
wherein at least one of the terminal and the transponder is structurally dedicated to operation where a distance between the terminal and the transponder exceeds a predetermined distance;
wherein the first resistor, the first capacitor and the first inductor are connected in series with one another, and wherein the second resistor, the second capacitor and the second inductor are connected in parallel with one another. - View Dependent Claims (22, 23, 24)
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Specification