COIL PAIR WITH CARRIER SUPPRESSION

• US 20090026266A1
• Filed: 07/24/2007
• Published: 01/29/2009
• Est. Priority Date: 07/24/2007
• Status: Active Grant

• Current Assignee: Infineon Technologies AG
• Original Assignee: Infineon Technologies AG
• Inventors: Raggam, Peter
• Granted Patent: US 7,925,223 B2
• Time in Patent Office: Days
• US Class Current: 235/439
• CPC Class Codes: G06K 7/0008 General problems related to the reading of electronic memory record carriers, independent of its reading method, e.g. power transfer
• CPC Class Codes: G06K 7/10316 using at least one antenna particularly designed for interrogating the wireless record carriers antennas in general H01Q1/22
• CPC Class Codes: H01Q 7/00 Loop antennas with a substantially uniform current distribution around the loop and having a directional radiation pattern in a plane perpendicular to the plane of the loop
• CPC Class Codes: H04B 1/68 for wholly or partially suppressing the carrier or one side band
• CPC Class Codes: H04B 5/00 Near-field transmission systems, e.g. inductive or capacitive transmission systems
• CPC Class Codes: H04B 5/0031 for data transfer
• CPC Class Codes: H04B 5/0087 with multiple coils at either side
• CPC Class Codes: H04B 5/263 Multiple coils at either side
• CPC Class Codes: H04B 5/72 for local intradevice communication

Abstract

A coil pair having a transmission coil and a reception coil. The transmission coil is configured to transmit a transmission signal having a carrier. The reception coil is configured to receive from a source a reception signal having the carrier and data, and to significantly suppress the carrier while maintaining coupling with the source at any position along and any position proximate to the reception coil.

Claims

1. A coil pair, comprising:

a transmission coil configured to transmit a transmission signal having a carrier; and

a reception coil configured to receive from a source a reception signal having the carrier and data, and to significantly suppress the carrier while maintaining coupling with the source at any position along and any position proximate to the reception coil.

2. The coil pair of claim 1, wherein the carrier field of the transmission signal is suppressed in the reception coil.

3. The coil pair of claim 1, wherein the transmission coil and the reception coil are each substantially circular and are concentrically located.

4. The coil pair of claim 1, wherein the transmission coil and the reception coil are each substantially rectangular and are concentrically located.

5. The coil pair of claim 1, wherein the transmission coil and the reception coil are each substantially circular and are concentrically located, and the reception coil is smaller than the transmission coil.

6. The coil pair of claim 1, wherein the reception coil is shaped substantially as shown in FIG. 1A.

7. The coil pair of claim 1, wherein the reception coil is shaped substantially as shown in FIG. 2A.

8. The coil pair of claim 1, wherein the reception coil is shaped substantially as shown in FIG. 3A.

9. The coil pair of claim 1, wherein the transmission coil and reception coil are located on opposing sides of a printed circuit board.

10. The coil pair of claim 1, wherein the transmission coil and reception coil are located on a same side of a printed circuit board.

11. The coil pair of claim 1, wherein the carrier is suppressed based at least in part on a coupling factor between the transmission coil and the reception coil.

12. The coil pair of claim 11, wherein the coupling factor is approximately zero.

13. The coil pair of claim 1, wherein the source is located within approximately 10 cm proximate to the reception coil.

14. A test setup apparatus comprising:

a coil pair comprising;

a transmission coil configured to transmit a transmission signal having a carrier; and

a reception coil configured to receive from a source a reception signal having the carrier and data, and to significantly suppress the carrier while maintaining coupling with the source at any position along and any position proximate to the reception coil; and

a receiver configured to measure a response signal strength of the source.

15. A contactless card reader, comprising:

a transmission coil configured to transmit a transmission signal having a carrier; and

a reception coil configured to receive from a contactless card a reception signal having the carrier and data, and to significantly suppress the carrier while maintaining coupling with the contactless card coil at any position along and any position proximate to the reception coil.

16. The contactless card reader of claim 15, further comprising a reader integrated circuit, wherein the reception coil is coupled directly to a receiver input of the reader integrated circuit.

17. The contactless card reader of claim 16, wherein an input voltage to the receiver input of the reader integrated circuit is approximately 3 volts.

18. The contactless reader of claim 16, wherein the reader integrated circuit is implemented using CMOS technology.

19. The contactless card reader of claim 15, wherein the transmission coil and the reception coil are each substantially circular and are concentrically located.

20. The contactless card reader of claim 15, wherein the transmission coil and the reception coil are each substantially rectangular and are concentrically located.

21. The contactless card reader of claim 15, wherein the transmission coil and the reception coil are each substantially circular and are concentrically located, and the reception coil is smaller than the transmission coil.

22. The contactless card reader of claim 16, further comprising:

an electromagnetic compatibility filter configured to filter out electromagnetic interference of a signal from the reader integrated circuit;

a matching circuit configured to maximize energy transfer of the filtered signal; and

a Q-factor adjuster configured to adjust gain of the matched, filtered signal,

wherein the gain adjusted signal is the transmission signal transmitted by the transmission coil.

23. The contactless card reader of claim 15, wherein the contactless card is a radio frequency identification (RFID) card.

24. The contactless card reader of claim 15, wherein the contactless card is a near field communication (NFC) device.

25. The contactless card reader of claim 15, wherein the contactless card is a proximity integrated circuit card (PICC).

26. A coil pair, comprising:

a transmission means for transmitting a transmission signal having a carrier; and

a reception means for receiving from a source a reception signal having the carrier and data, and for significantly suppressing the carrier while maintaining coupling with the source at any position along and any position proximate to the reception means.

27. A data transmission method comprising:

transmitting by a transmission coil a transmission signal having a carrier;

receiving, by a reception coil, from a source a reception signal having the carrier and data; and

significantly suppressing the carrier while maintaining coupling with the source at any position along and any position proximate to the reception coil.

28. The data transmission method of claim 27, wherein the suppression of the carrier comprises the reception field of the reception signal canceling the transmission field of the transmission signal.

29. A reception coil, which is coupled with a transmission coil, and is configured to receive from a source a reception signal having a carrier and data and to significantly suppress the carrier while maintaining coupling with the source at any position along and any position proximate to the reception coil, wherein the reception coil is separate from the transmission coil.