System for contactless power and data transmission

• US 5,953,642 A
• Filed: 04/28/1997
• Issued: 09/14/1999
• Est. Priority Date: 10/26/1994
• Status: Expired due to Term

• Current Assignee: Infineon Technologies AG
• Original Assignee: Siemens AG
• Inventors: Marquardt, Kurt, Feldtkeller, Martin, Reiner, Robert, Greiderer, Reinhard, Nolles, Jurgen
• Primary Examiner(s): Eisenzopf, Reinhard J.
• Assistant Examiner(s): Bhattacharya, Sam
• Application Number:
  US08/847,866
• Time in Patent Office: 869 Days
• Field of Search: 455/150.1, 455/151.2, 455/191.1, 455/193.2, 455/195.1, 455/290, 455/193.1, 340/825.34, 340/825.54, 334/55
• US Class Current: 455/195.1
• 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: H01F 2038/146 in combination with capacitive coupling
• CPC Class Codes: H03J 2200/10 Tuning of a resonator by means of digitally controlled capacitor bank

Abstract

In a system for contactless power and data transmission, a transmitting or receiving station has at least one transmitting or receiving resonant circuit which is driven by an integrable control circuit. The integrated control circuit has a multiplicity of capacitors which can be switched in, in parallel with the resonant circuit. A device is provided for driving the switching device.

Claims

1. In a system for contactless power and data transmission between a mobile station and a stationary station, the mobile station comprising:

a tunable resonant circuit;

a control circuit driving said resonant circuit, said control circuit having a multiplicity of capacitive circuits including a first capacitor, a second capacitor, a connection node, and at least one switching device;

said at least one switching device in a given switching state connecting said first capacitor and said second capacitor in series and connecting said resonant circuit in parallel with said series-connected first and second capacitors, and said at least one switching device in said given switching state connecting said connection node between said first capacitor and said second capacitor;

a device for driving said switching device; and

a terminal for a reference potential to be connected to said connection node.

2. The system according to claim 1, wherein said device for driving said switching device tunes said resonant circuit starting from a mean value, during start-up of the system, by causing said switching device to enter into said given switching state or to exit from said given switching state.

3. The system according to claim 2, including a nonvolatile memory device for storing determined values for tuning said resonant circuit.

4. The system according to claim 1, wherein said resonant circuit has a first terminal connected to said first capacitor and a second terminal connected to said second capacitor, said at least one switching device connects said first capacitor and said second capacitor to said terminal for the reference potential, and said at least one switching device can be driven with the same biasing.

5. The system according to claim 4, wherein the reference potential is a supply potential.

6. The system according to claim 5, wherein the supply potential is obtained from a voltage to be picked off at said terminals of said resonant circuit by rectification and smoothing.