Chip card and control element

• US 9,984,321 B2
• Filed: 12/18/2015
• Issued: 05/29/2018
• Est. Priority Date: 12/29/2014
• Status: Active Grant

• Current Assignee: Infineon Technologies AG
• Original Assignee: Infineon Technologies AG
• Inventors: Rampetzreiter, Stephan, Buchsbaum, Martin, Jongsma, Jakob, Skacel, Georg, Wedl, Bernhard, Woerle, Andreas
• Primary Examiner(s): ELLIS, SUEZU Y
• Application Number:
  US14/973,802
• Publication Number:
  US 20160189024A1
• Time in Patent Office: 893 Days
• CPC Class Codes: G06K 19/0723 the record carrier comprising an arrangement for non-contact communication, e.g. wireless communication circuits on transponder cards, non-contact smart cards or RFIDs
• CPC Class Codes: G06K 19/0726 the arrangement including a circuit for tuning the resonance frequency of an antenna on the record carrier
• CPC Class Codes: G06K 19/07794 the record carrier comprising a booster or auxiliary antenna in addition to the antenna connected directly to the integrated circuit

Abstract

According to one embodiment, a chip card is described including a chip, an antenna, a coupling structure configured to transmit energy from the antenna to the chip and a control element configured to control, depending on a field strength of a magnetic field to which the chip card is exposed, at least one of the resonance frequency of the antenna, the quality factor of the antenna and an energy transmission efficiency of the coupling structure.

Claims

1. A chip card, comprising:

a chip;

an antenna;

a coupling structure configured to provide energy from the antenna to the chip; and

a circuit component configured to control, depending on a field strength of a magnetic field to which the chip card is exposed, at least one of a resonance frequency of the antenna, a quality factor of the antenna and an energy transmission efficiency of the coupling structure,

wherein the circuit component is configured to shift the resonance frequency of the antenna away from a predetermined system frequency with increasing field strength of the magnetic field above a threshold of the field strength of the magnetic field.

2. The chip card of claim 1,

wherein the antenna is galvanically coupled to the chip by the coupling structure.

3. The chip card of claim 1,

wherein the circuit component is configured to reduce the quality factor of the antenna with increasing field strength of the magnetic field above a threshold of the field strength of the magnetic field.

4. The chip card of claim 1,

wherein the antenna is a booster antenna;

wherein the chip card comprises a chip module antenna circuit comprising the chip and a chip module antenna;

wherein the chip card comprises a booster antenna circuit comprising the booster antenna and a coupling antenna inductively coupled to the chip module antenna, wherein the booster antenna circuit forms a resonant circuit;

wherein the coupling structure includes the chip module antenna and the coupling antenna; and

wherein the circuit component is configured to control at least one of the resonance frequency of the booster antenna circuit, the quality factor of the booster antenna circuit and an inductive coupling between the booster antenna circuit and the chip module antenna circuit depending on the field strength of the magnetic field to which the chip card is exposed.

5. The chip card of claim 4,

wherein the circuit component is configured to control a mutual inductance of the coupling antenna and the chip module antenna depending on the field strength of the magnetic field.

6. The chip card of claim 5,

wherein the circuit component is configured to decrease the mutual inductance of the coupling antenna and the chip module antenna with increasing field strength of the magnetic field above a threshold of the field strength of the magnetic field.

7. The chip card of claim 4,

wherein the circuit component includes a voltage limiting element arranged to shorten at least a part of the coupling antenna or the chip module antenna.

8. The chip card of claim 4,

wherein the circuit component includes a ferrite core of the coupling antenna.

9. The chip card of claim 4,

wherein the booster antenna circuit further comprises a sense antenna and the circuit component includes a ferrite core of the sense antenna.

10. The chip card of claim 1,

wherein the circuit component includes a variable resistor.

11. The chip card of claim 10,

wherein the variable resistor is a resistor whose resistance depends on a field strength of a magnetic field to which it is exposed.

12. The chip card of claim 11,

wherein the variable resistor comprises a structure having a giant magnetoresistance effect associated therewith.

13. The chip card of claim 10,

wherein the variable resistor is disposed in physical contact with the chip so as to be heated by the chip.

14. The chip card of claim 1,

wherein the circuit component includes a voltage limiting element.

15. The chip card of claim 14,

wherein the voltage limiting element is an element with a non-linear voltage-dependent resistance.

16. The chip card of claim 14,

wherein the voltage limiting element comprises a diode or a varistor.

17. A chip card, comprising:

a chip;

an antenna;

a coupling structure configured to provide energy from the antenna to the chip; and

a circuit component configured to control, depending on a field strength of a magnetic field to which the chip card is exposed, a quality factor of the antenna,

wherein the circuit component is configured to reduce the quality factor of the antenna with increasing field strength of the magnetic field above a threshold of the field strength of the magnetic field.

18. A chip card, comprising:

a chip module antenna circuit including

a chip, and

a chip module antenna;

a booster antenna circuit including

a booster antenna, and

a coupling antenna inductively coupled to the chip module antenna;

a coupling structure configured to provide energy from the booster antenna to the chip, the coupling structure including

the chip module antenna, and

the coupling antenna; and

a circuit component configured to control, depending on a field strength of a magnetic field to which the chip card is exposed, a mutual inductance of the coupling antenna and the chip module antenna depending on the field strength of the magnetic field.

19. The chip card of claim 18,

wherein the circuit component is configured to decrease the mutual inductance of the coupling antenna and the chip module antenna with increasing field strength of the magnetic field above a threshold of the field strength of the magnetic field.

20. A chip card, comprising:

a chip;

an antenna;

a coupling structure configured to provide energy from the antenna to the chip; and

a circuit component configured to control, depending on a field strength of a magnetic field to which the chip card is exposed, at least one of a resonance frequency of the antenna, a quality factor of the antenna and an energy transmission efficiency of the coupling structure,

wherein the circuit component includes a variable resistor whose resistance depends on the field strength of the magnetic field to which it is exposed, the variable resistor comprising a structure having a giant magnetoresistance effect associated therewith.