Antenna for communication with a multitude of transponders

• US 7,570,168 B2
• Filed: 07/13/2005
• Issued: 08/04/2009
• Est. Priority Date: 07/16/2004
• Status: Active Grant

• Current Assignee: NXP B.V. (NXP Semiconductors NV)
• Original Assignee: NXP B.V. (NXP Semiconductors NV)
• Inventors: Hubmer, Paul, Schwar, Christian
• Primary Examiner(s): CHEN, SHIH CHAO
• Application Number:
  US11/632,733
• Publication Number:
  US 20080169985A1
• Time in Patent Office: 1,483 Days
• Field of Search: 343/741, 343/742, 343/867, 340/572.1
• US Class Current: 340/572.1
• 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 1/22 by structural association with other equipment or articles

Abstract

An antenna (1) for communication with a multitude of transponders (6a . . . 6c) is provided, the antenna (1) having an antenna conductor (2) which completely encloses at least one read/write region (4c) intended for a transponder (6c) individually and/or, when a multitude of read/write regions (4a, 4b) are arranged within a continuous inner region (3) enclosed by the antenna conductor (2), the inner region (3) has constrictions (5a) between the read/write regions (4a, 4b) so that the antenna conductor (2) largely encloses these read/write regions (4a, 4b) individually. The electromagnetic field radiated by the antenna (1) is thereby concentrated on the read/write regions (4a . . . 4c).

Claims

1. An antenna for communication with a multitude of transponders, comprising:

an antenna conductor having a first conductor end and a second conductor end, said antenna conductor extending from the first conductor end to the second conductor end, in an arrangement that encloses a multitude of read/write regions intended for transponders wherein

a portion of the antenna conductor completely encloses a first read/write region individually and another portion of the antenna conductor at least substantially encloses a second read/write region individually.

2. The antenna of claim 1, wherein the portion of antenna conductor that encircles the first read/write region encircles said region by more than 360 degrees.

3. The antenna of claim 2, wherein the portion of said antenna conductor that encircles the second read/write region completely encircles said region by more than 360 degrees, and

wherein said conductor is arranged such that the first read/write portion is adjacent the second read/write portion, and

wherein the portion of the antenna conductor that completely encircles the first read/write region encircles said region in one directional sense and the portion of the antenna conductor that completely encircles the adjacent second read/write region encircles said regions in an opposite directional sense.

4. The antenna of claim 1, wherein the first and the second read/write regions respectively lie in mutually parallel planes or in a single plane and at least a portion of the antenna conductor is in the respective plane of a read/write regions.

5. The antenna of claim 1, wherein the first and the second read/write regions lie on a geometrical surface and a portion of the antenna conductor is on said geometrical surface.

6. The antenna of claim 1, wherein the antenna conductor is formed such that a given antenna of a given transponder can be arranged fully within at least one of the first and second read/write regions.

7. The antenna of claim 1, further comprising:

a supply device connected to the first end and to the second end of the conductor for supplying the antenna with electric power, and

an evaluation unit coupled to the antenna.

8. An antenna for communication with a multitude of transponders, comprising:

an antenna conductor extending in an arrangement that encloses a continuous inner region, said region having;

a first substantially enclosed read/write region,

a second substantially enclosed read write region spaced apart from said first substantially enclosed read write region, and

a constricted region connecting the first and second substantially enclosed read/write region,

wherein the constricted region is defined by two adjacently extending, spaced apart portions of the antenna conductor.

9. The antenna of claim 8, wherein the two adjacently extending, spaced apart portions of the antenna conductor extend substantially parallel to each another.

10. The antenna of claim 9, wherein the ratio of the maximum circle formable within any one of the first and the second read/write regions to the minimum circle tangentially contacting each of the two substantially parallel, spaced apart portions of the antenna conductor defining the constricted region is at least 1.5.

11. The antenna of claim 10, wherein the center spacing between the maximum circle formable within the first read/write region and the maximum circle formable within the second read/write portion has a minimum value of at least 1.5 times the sum of the respective radii of said maximum circles.

12. The antenna of claim 8, wherein the first and the second read/write regions, and the constricted region respectively lie in mutually parallel planes or in a single plane.

13. The antenna of claim 8, wherein the antenna conductor is arranged such that the first and the second read/write regions lie on a geometrical surface.

14. The antenna of claim 8, wherein the antenna conductor is formed such that a given antenna of a given transponder can be arranged fully within either of the first and second read/write regions.

15. The antenna of claim 14 further comprising:

a supply device connected to the first end and to the second end of the conductor for supplying the antenna with electric power; and

an evaluation unit coupled to the antenna.

16. The antenna of claim 8, wherein the antenna conductor has a first end and a second end, and extends from the first end to the second end.

17. An antenna for communication with a multitude of transponders, comprising:

an antenna conductor having a first conductor end and a second conductor end, said antenna conductor extending from the first conductor end to the second conductor end, in an arrangement having

a first portion that completely encloses a first read/write region individually, and

a second portion that encloses a continuous inner region spaced apart from said first read/write region, wherein said continuous inner region comprises;

a second substantially enclosed read/write region,

a third substantially enclosed read write region spaced apart from said second substantially enclosed read write region, and

a constricted region connecting the second and third substantially enclosed read/write regions,

wherein the constricted region is defined by two adjacently extending, spaced apart portions of the antenna conductor.

18. The antenna of claim 17, wherein the two adjacently extending, spaced apart portions of the antenna conductor extend substantially parallel to each another.

19. The antenna of claim 18, wherein the ratio of the maximum circle formable within any one of the second and the third read/write regions to the minimum circle tangentially contacting the two substantially parallel lengths defining the constricted region is at least 1.5.

20. The antenna of claim 19, wherein the center spacing between the maximum circle formable within the second read/write region and the maximum circle formable within the third read/write portion has a minimum value of at least 1.5 times the sum of the respective radii of said maximum circles.

21. The antenna of claim 17, wherein the first, the second and the third read/write regions, and the constricted region respectively lie in mutually parallel planes or in a single plane.

22. The antenna of claim 17, wherein the antenna conductor is arranged such that the constricted region and the first, the second, and the third read/write regions lie on a geometrical surface.

23. The antenna of claim 17, wherein the antenna conductor is formed such that a given antenna of a given transponder can be arranged fully within any of the first, second and third read/write regions.

24. The antenna of claim 17, wherein the antenna conductor has a first end and a second end, and extends from the first end to the second end.

25. The antenna of claim 24, further comprising:

a supply device connected to the first end and to the second end of the conductor for supplying the antenna with electric power; and

an evaluation unit coupled to the antenna, wherein the antenna conductor is arranged such that the constricted region and the first, the second, and the third read/write regions lie on a geometrical surface.