APPARATUS COMPRISING INDUCTIVE COUPLING COMMUNICATION MEANS

• US 20130183897A1
• Filed: 03/11/2013
• Published: 07/18/2013
• Est. Priority Date: 10/19/2010
• Status: Active Grant

• Current Assignee: Verimatrix Incorporated (Verimatrix SA)
• Original Assignee: Inside Secure SA
• Inventors: CORDIER, Nicolas, PERNISEK, Florian
• Granted Patent: US 9,473,215 B2
• Time in Patent Office: Days
• US Class Current: 455/41.1
• CPC Class Codes: G06F 1/1698 the I/O peripheral being a sending/receiving arrangement to establish a cordless communication link, e.g. radio or infrared link, integrated cellular phone details of antennas disposed inside a computer H01Q1/2266
• 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 7/10237 the reader and the record carrier being capable of selectively switching between reader and record carrier appearance, e.g. in near field communication [NFC] devices where the NFC device may function as an RFID reader or as an RFID tag
• CPC Class Codes: G06K 7/10336 the antenna being of the near field type, inductive coil
• CPC Class Codes: G06K 7/10386 the interrogation device being of the portable or hand-handheld type, e.g. incorporated in ubiquitous hand-held devices such as PDA or mobile phone, or in the form of a portable dedicated RFID reader
• CPC Class Codes: H01Q 1/243 with built-in antennas
• CPC Class Codes: H01Q 1/50 Structural association of antennas with earthing switches, lead-in devices or lightning protectors
• 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: H01Q 7/005 with variable reactance for tuning the antenna
• CPC Class Codes: H04B 5/26 using coils
• CPC Class Codes: H04B 5/266 One coil at each side, e.g. with primary and secondary coils
• CPC Class Codes: H04B 5/43 Antennas
• CPC Class Codes: H04B 5/72 for local intradevice communication
• CPC Class Codes: H04M 1/72412 using two-way short-range wireless interfaces
• CPC Class Codes: H04M 2250/04 including near field communication means, e.g. RFID

Abstract

An apparatus including inductive coupling communication circuitry configured to communicate in peer-to-peer mode with an identical apparatus includes an antenna coil presenting, relative to a longitudinal median or a transversal median axis of the antenna coil, an asymmetry corresponding to a coverage rate less than or equal to 0.6 if the antenna coil comprises 4 or more loops, less than or equal to 0.7 if the antenna coil comprises 3 loops, or less than or equal to 0.8 if the antenna coil comprises 1 or 2 loops.

Claims

1. An apparatus comprising inductive coupling communication circuitry configured to communicate in peer-to-peer mode with an identical apparatus, the communication circuitry comprising a communication controller and a planar antenna coil tuned to a working frequency, linked to the controller by way of two connection points and comprising N loops arranged in series between the two connection points,

wherein:

the antenna coil presents, relative to a longitudinal median or a transversal median axis of the antenna coil, an asymmetry corresponding to a coverage rate less than or equal to 0.6 if the antenna coil comprises 4 or more loops, less than or equal to 0.7 if the antenna coil comprises 3 loops, or less than or equal to 0.8 if the antenna coil comprises 1 or 2 loops,

the coverage rate being equal to the sum of mutually opposite surfaces of loops of the same rank divided by the sum of surfaces of loops of the antenna coil, when the antenna coil is arranged in maximum mutual opposition with an identical antenna coil.

2. The apparatus according to claim 1, wherein the number N of loops of the antenna coil arranged in series between the two connection points is at most equal to 3.

3. The apparatus according to claim 2, wherein the antenna coil presents a coverage rate less than or equal to 0.7, irrespective of the number of loops it has.

4. The apparatus according to claim 1, wherein the antenna coil comprises at least one loop having a zero coverage rate.

5. The apparatus according to claim 1, wherein the antenna coil comprises at least one composite loop comprising two juxtaposed loops not having any common surface.

6. The apparatus according to claim 1, wherein the antenna coil comprises at least one supplementary tuning loop arranged between one of the two connection points and at least a third connection point, a supplementary tuning loop not intervening in the determination of the coverage rate of the antenna coil.

7. The apparatus according to claim 1, wherein:

the antenna coil is arranged proximate one wall of the apparatus presenting a longitudinal median axis,

the antenna coil presents a longitudinal median axis that is the same as the longitudinal median axis of the wall.

8. The apparatus according to claim 1, wherein the antenna coil is arranged proximate one wall of the apparatus, in a plane situated at less than 5 millimeters from an external face of the wall.

9. A method of limiting frequency detuning between first and second identical planar antenna coils turned to a working frequency, when the antenna coils are arranged opposite each other at a distance less than 10 millimeters, each antenna coil comprising N loops arranged in series between two connection points of the antenna coil, the method comprising:

conferring to each antenna coil, relative to a longitudinal median or a transversal median axis of the antenna coil, an asymmetry corresponding to a coverage rate less than or equal to 0.6 if the antenna coil comprises 4 or more loops, less than or equal to 0.7 if the antenna coil comprises 3 loops, or less than or equal to 0.8 if the antenna coil comprises 1 or 2 loops,

the coverage rate being equal to the sum of mutually opposite surfaces of loops of the same rank divided by the sum of surfaces of loops of the antenna coil, when the antenna coils are in maximum mutual opposition.

10. The method according to claim 9, further comprising choosing a number N of loops arranged in series between the two connection points that is at most equal to 3.

11. The method according to claim 10, further comprising conferring to each antenna coil a coverage rate less than or equal to 0.7, irrespective of the number of loops.

12. The method according to claim 9, further comprising providing in each antenna coil at least one loop having a zero coverage rate.

13. The method according to claim 9, further comprising providing in each antenna coil at least one composite loop comprising two juxtaposed loops not having any common surface.

14. The method according to claim 9, further comprising providing in each antenna coil at least one supplementary tuning loop arranged between one of the two connection points and at least a third connection point, and not taking into consideration the supplementary tuning loop in the determination of the coverage rate of the antenna coil.

15. A method for establishing an inductive coupling communication between two identical apparatuses each comprising inductive coupling communication circuitry configured to communicate in peer-to-peer mode, the communication circuitry comprising a communication controller and a planar antenna coil tuned to a working frequency, linked to the controller by way of two connection points and comprising N loops arranged in series between the two connection points, the method comprising

placing walls of the two apparatuses mutually opposite such that the antenna coils are arranged opposite each other at a distance less than 10 millimeters,

conferring to each antenna coil, relative to a longitudinal median or a transversal median axis of the antenna coil, an asymmetry corresponding to a coverage rate less than or equal to 0.6 if the antenna coil comprises 4 or more loops, less than or equal to 0.7 if the antenna coil comprises 3 loops, or less than or equal to 0.8 if the antenna coil comprises 1 or 2 loops,

the coverage rate being equal to the sum of mutually opposite surfaces of loops of the same rank divided by the sum of surfaces of loops of the antenna coil, when the antenna coils are in maximum mutual opposition.

16. The method according to claim 15, further comprising choosing a number N of loops arranged in series between the two connection points that is at most equal to 3.

17. The method according to claim 16, further comprising conferring to each antenna coil a coverage rate less than or equal to 0.7, irrespective of the number of loops it has.

18. The method according to claim 15, further comprising providing in each antenna coil at least one loop having a zero coverage rate.

19. The method according to claim 15, further comprising providing in each antenna coil at least one composite loop comprising two juxtaposed loops not having any common surface.

20. The method according to claim 15, further comprising providing in each antenna coil at least one supplementary tuning loop arranged between one of the two connection points and at least one third connection point, and not taking into consideration the supplementary tuning loop in the determination of the coverage rate of the antenna coil.

21. The method according to claim 15, further comprising:

conferring to the antenna coil a form presenting a longitudinal median axis, and

arranging the antenna coil proximate a wall of the apparatus presenting a longitudinal median axis situated at mid-distance between the lateral edges of the wall, such that the longitudinal median axis of the antenna coil is the same as the longitudinal median axis of the wall.