Electronic entity having a magnetic antenna

• US 7,830,324 B2
• Filed: 06/20/2006
• Issued: 11/09/2010
• Est. Priority Date: 06/27/2005
• Status: Active Grant

• Current Assignee: IDEMIA France (Advent International Corporation)
• Original Assignee: Oberthur Technologies SA
• Inventors: Eray, Yves
• Primary Examiner(s): Nguyen; Hoang V
• Application Number:
  US11/993,879
• Publication Number:
  US 20080211728A1
• Time in Patent Office: 1,603 Days
• Field of Search: 343/895, 343/788, 343/741, 343/742, 343/866, 343/867, 343/870
• US Class Current: 343/788
• CPC Class Codes: G06K 19/07749 the record carrier being capable of non-contact communication, e.g. constructional details of the antenna of a non-contact smart card
• CPC Class Codes: H01Q 1/22 by structural association with other equipment or articles
• CPC Class Codes: H01Q 1/2208 associated with components used in interrogation type services, i.e. in systems for information exchange between an interrogator/reader and a tag/transponder, e.g. in Radio Frequency Identification [RFID] systems methods or arrangements for sensing record carriers, e.g. for reading patterns G06K7/00; record carrier for use with machines and with at least a part designed to carry digital markings G06K19/00
• 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

Abstract

An electronic entity includes an electronic circuit (21) having at least one first terminal (22) and a second terminal (24) to which an antenna is connected. The antenna includes a conducting element (26) electrically connected to the first terminal (22) of the electronic circuit (21) and includes a resonator (28) insulated from the conducting element (26) at the antenna, electrically connected to the second terminal (24) of the electronic circuit (21) and coupled to the conducting element (26).

Claims

1. An electronic entity comprising:

an electronic circuit having at least a first terminal and a second terminal to which a magnetic antenna is connected,

wherein the antenna comprises a conductive member (6;

16;

26;

36) electrically connected to the first terminal of the electronic circuit and a resonator (8;

18;

28;

38) having a Q enabling amplification at the communication frequency of the electronic circuit, isolated from the conductive member (6;

16;

26;

36) at the level of the antenna, electrically connected to the second terminal of the electronic circuit, and coupled to the conductive member (6;

16;

26;

36).

2. The electronic entity according to claim 1, wherein the resonator (8;

18;

28;

38) is capacitively coupled to the conductive member (6;

16;

26;

36).

3. The electronic entity according to claim 2, wherein the capacitance of the conductive member is negligible compared to the coupling capacitance (C_c).

4. The electronic entity according to claim 2, wherein the resonator (8;

18;

28) comprises a turn facing the conductive member (6;

16;

26) over at least a portion of its perimeter.

5. The electronic entity according to claim 4, wherein the turn faces the conductive member (6;

16;

26) over virtually all of its perimeter.

6. The electronic entity according to claim 4, wherein the turn and the conductive member (6;

16;

26) are situated at a distance less than 0.5 mm over said perimeter portion.

7. The electronic entity according to claim 1, wherein the conductive member is formed by a turn portion.

8. The electronic entity according to claim 1, wherein the capacitance of the conductive member is negligible compared to the capacitance (C_R) of the resonator.

9. The electronic entity according to claim 1, wherein the inductance of the conductive member is negligible compared to the inductance (L_R) of the resonator.

10. The electronic entity according to claim 1, wherein the resonator (8;

18;

28;

38) takes the form of a conductive winding having at least one free end.

11. The electronic entity according to claim 10, wherein the resonator (28;

38) is connected to the second terminal by the end of the winding opposite the free end.

12. The electronic entity according to claim 10, wherein said conductive winding comprises a plurality of turns.

13. The electronic entity according to claim 12, wherein the turns are separated two by two by a distance less than 0.5 mm.

14. The electronic entity according to claim 10, wherein the conductive member is inside the area defined by the resonator.

15. The electronic entity according to claim 1, wherein the conductive member (6;

16;

26;

36) and the resonator (8;

18;

28;

38) are deposited on a common plane support.

16. The electronic entity according to claim 1, wherein the resonant frequency of the resonator alone is not more than 10% greater than a communication frequency of the electronic circuit.

17. The electronic entity according to claim 1, wherein the electronic circuit operates at a communication frequency below 100 MHz.

18. The electronic entity according to claim 17, wherein said communication frequency is from 1 MHz to 50 MHz.

19. The electronic entity according to claim 18, wherein the communication frequency is from 13 MHz to 15 MHz.

20. The electronic entity according to claim 19, wherein the resonant frequency of the resonator alone is from 13.6 MHz to 17 MHz.

21. The electronic entity according to claim 1, having overall exterior dimensions less than 100 mm.

22. The electronic entity according to claim 21, wherein the resonator (8;

18) comprises more than ten turns.

23. The electronic entity according to claim 21, wherein said exterior dimensions are less than 30 mm.

24. A pocket electronic entity according to claim 1.

25. The electronic entity according to claim 1, forming a microcircuit card.

26. The electronic entity according to claim 25, wherein the antenna extends over about half the area of the card.

27. The electronic entity according to claim 1, wherein the end of the conductive member (6;

26;

36) opposite the first terminal of the electronic circuit is free.

28. The electronic entity according to claim 1, constituting an electronic identity document.

29. An electronic entity comprising:

an electronic circuit having at least a first terminal and a second terminal to which an antenna is connected,

wherein the antenna comprises a conductive member (6;

16;

26;

36) electrically connected to the first terminal of the electronic circuit and a resonator (8;

18;

28;

38) having a Q enabling amplification at the communication frequency of the electronic circuit, isolated from the conductive member (6;

16;

26;

36) at the level of the antenna, electrically connected to the second terminal of the electronic circuit, and coupled to the conductive member (6;

16;

26;

36), and the resonator (8;

18;

28;

38) takes the form of a conductive winding having two free ends.

30. The electronic entity according to claim 29, wherein said conductive winding comprises a plurality of turns.

31. The electronic entity according to claim 30, wherein the turns are separated two by two by a distance less than 0.5 mm.

32. The electronic entity according to claim 29, wherein the conductive member is inside the area defined by the resonator.

33. An electronic entity comprising:

an electronic circuit having at least a first terminal and a second terminal to which an antenna is connected,

wherein the antenna comprises a conductive member (6;

16;

26;

36) electrically connected to the first terminal of the electronic circuit and a resonator (8;

18;

28;

38) having a Q enabling amplification at the communication frequency of the electronic circuit, isolated from the conductive member (6;

16;

26;

36) at the level of the antenna, electrically connected to the second terminal of the electronic circuit, and coupled to the conductive member (6;

16;

26;

36), and the resonator (8;

18;

28;

38) is inside the conductive member (6;

16;

26;

36).

34. An electronic entity comprising:

an electronic circuit having at least a first terminal and a second terminal to which an antenna is connected,

wherein the antenna comprises a conductive member (6;

16;

26;

36) electrically connected to the first terminal of the electronic circuit and a resonator (8;

18;

28;

38) having a Q enabling amplification at the communication frequency of the electronic circuit, isolated from the conductive member (6;

16;

26;

36) at the level of the antenna, electrically connected to the second terminal of the electronic circuit, and coupled to the conductive member (6;

16;

26;

36), and

the projection of the circuit formed by the antenna and the electronic circuit in a plane that is substantially parallel to that projection forms a line with no intersections and wherein the antenna comprises a winding (8;

18;

28;

38) that extends over strictly more than one turn.

35. An electronic entity comprising:

an electronic circuit having at least a first terminal and a second terminal to which an antenna is connected,

wherein the antenna comprises a conductive member (6;

16;

26;

36) electrically connected to the first terminal of the electronic circuit and a resonator (8;

18;

28;

38) having a Q enabling amplification at the communication frequency of the electronic circuit, isolated from the conductive member (6;

16;

26;

36) at the level of the antenna, electrically connected to the second terminal of the electronic circuit, and coupled to the conductive member (6;

16;

26;

36), and

the conductive member is produced in a first plane, the resonator is produced in a second plane different from the first plane, and the resonator is in line with the conductive member.

36. The electronic entity according to claim 35, wherein a median turn of the resonator is in line with the conductive member.

37. An electronic entity comprising:

an electronic circuit having at least a first terminal and a second terminal to which an antenna is connected,

wherein the antenna comprises a conductive member (6;

16;

26;

36) electrically connected to the first terminal of the electronic circuit and a resonator (8;

18;

28;

38) having a Q enabling amplification at the communication frequency of the electronic circuit, isolated from the conductive member (6;

16;

26;

36) at the level of the antenna, electrically connected to the second terminal of the electronic circuit, and coupled to the conductive member (6;

16;

26;

36), and the conductive member (16) forms a loop connected at both ends to the first terminal of the electronic circuit.