Gate antenna device

• US 20050057422A1
• Filed: 08/31/2004
• Published: 03/17/2005
• Est. Priority Date: 09/01/2003
• Status: Active Grant

• Current Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Inventors: Yoshinaga, Hiroshi, Tanaka, Masahiko, Deguchi, Futoshi, Haruyama, Hiroaki
• Granted Patent: US 7,227,504 B2
• Time in Patent Office: Days
• US Class Current: 343/867
• CPC Class Codes: G06K 7/10178 including auxiliary means for focusing, repeating or boosting the electromagnetic interrogation field comparable booster antennas integrated on the record carrier itself G06K19/07794
• CPC Class Codes: G06K 7/10336 the antenna being of the near field type, inductive coil
• CPC Class Codes: H01Q 1/2216 used in interrogator/reader equipment
• CPC Class Codes: H01Q 19/005 Patch antenna using one or more coplanar parasitic elements
• 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

The invention is aimed at providing a gate antenna device which expands the distance and range of communication with an IC-integrated medium and improves the accuracy of communication while suppressing power consumption and leakage electric fields. A gate antenna device having a plurality of loop antennas which supplies power and transmission data to an IC-integrated medium through electromagnetic induction and acquires reception data in the form of a fluctuation of a load from the IC-integrated medium. The plurality of loop antennas include a power-fed loop antenna to which a signal current is supplied and a non-power-fed loop antenna to which no signal current is supplied.

Claims

1. A gate antenna device having a plurality of antennas, wherein the plurality of antennas include a power-fed antenna to which a signal current is supplied and a non-power-fed antenna to which no signal current is supplied.

2. The gate antenna device according to claim 1, wherein the plurality of antennas are antennas which supply power to a radio communication medium through electromagnetic induction and receive data from the radio communication medium.

3. The gate antenna device according to claim 2, wherein the plurality of antennas supply transmission data to the radio communication medium to a radio communication medium through electromagnetic induction.

4. The gate antenna device according to claim 1, wherein the data from the radio communication medium are acquired in the form of a fluctuation of a load from the radio communication medium to the antennas.

5. The gate antenna device according to claim 1, wherein an electromagnetic wave leakage prevention member is provided on the plurality of antennas, the member being provided outside a principal plane formed by the antennas and at least outside the power-fed antenna.

6. The gate antenna device according to claim 1, wherein the electromagnetic wave leakage prevention member is a metal member or conductive member having a surface area which is 1.1 times or more the surface area of the principal plane formed by the antennas.

7. The gate antenna device according to claim 5, wherein a magnetic member is provided between the antennas and the electromagnetic wave leakage prevention member.

8. The gate antenna device according to claim 1, wherein a terminating resistance is connected to the antennas.

9. The gate antenna device according to claim 1, wherein a resonance circuit is connected to the non-power-fed antenna.

10. The gate antenna device according to claim 9, wherein the resonance circuit generates a frequency resonant to a desired frequency and wherein the resonance frequency is variable.

11. The gate antenna device according to claim 9, wherein the resonance circuit is a variable capacity connected in series with the non-power-fed antenna.

12. The gate antenna device according to claim 1, wherein a matching circuit is connected to the non-power-fed antenna.

13. The gate antenna device according to claim 12, wherein the matching circuit is a capacity connected in parallel with the terminating resistance.

14. The gate antenna device according to claim 1, wherein the non-power-fed antenna is surrounded by a bag-shaped comb-type conductive line having a comb-type arrangement.

15. The gate antenna device according to claim 1, wherein the plurality of antennas are loop antennas having an open plane and wherein the plurality of loop antennas include a power-fed loop antenna to which a signal current is supplied and a non-power-fed antenna to which no signal current is supplied.

16. The gate antenna device according to claim 15, wherein the plurality of loop antennas are disposed such that the open planes formed by the loops are substantially in parallel with each other.

17. The gate antenna device according to claim 15, wherein an electromagnetic wave leakage prevention member is provided on the plurality of antennas, the member being provided outside an open plane formed by the antennas and at least outside the power-fed antenna.

18. The gate antenna device according to claim 17, wherein the electromagnetic wave leakage prevention member is a metal member or conductive member having a surface area which is 1.1 times or more the surface area of the open planes defined by the loops of the loop antennas.

19. The gate antenna device according to claim 17, wherein a magnetic member is provided between the loop antennas and the electromagnetic wave leakage prevention member.

20. The gate antenna device according to claim 15, wherein a terminating resistance is connected to the loop antennas.

21. The gate antenna device according to claim 15, wherein a resonance circuit is connected to the non-power-fed loop antenna.

22. The gate antenna device according to claim 21, wherein the resonance circuit generates a frequency resonant to a desired frequency and wherein the resonance frequency is variable.

23. The gate antenna device according to claim 21, wherein the resonance circuit is a variable capacity connected in series with the non-power-fed loop antenna.

24. The gate antenna device according to claim 21, wherein a matching circuit is connected to the non-power-fed loop antenna.

25. The gate antenna device according to claim 22, wherein the matching circuit is a capacity connected in parallel with the terminating resistance.

26. The gate antenna device according to claim 15, wherein the non-power-fed loop antenna is surrounded by a bag-shaped comb-type conductive line having a comb-type arrangement.

27. The gate antenna device according to claim 15, wherein the one or more non-power-fed loop antennas are provided on both sides of the power-fed loop antenna.

28. The gate antenna device according to claim 15, wherein at least one power-fed loop antenna is provided such that it is sandwiched by a plurality of the non-power-fed loop antennas.

29. The gate antenna device according to claim 15, wherein the power-fed loop antennas and the non-power-fed loop antennas are alternately provided.

30. The gate antenna device according to claim 27, wherein an open plane of the power-fed loop antenna and an open plane of the non-power-fed loop antenna are substantially in parallel with each other.

31. A gate antenna device comprising an antenna set constituted by a power-fed antenna to which a signal current is supplied and a non-power-fed antenna to which no signal current is supplied, the antennas being provided adjacent to each other to form a pair, wherein one or more antenna sets are provided in a space having X, Y, and Z axes which are orthogonal to each other, the antenna sets being provided on two or more of the X, Y, and Z axes.

32. The gate antenna device according to claim 31, wherein adjoining ones of the antenna sets cross each other at an angle of about 90 deg when the antenna sets are disposed on four planes in an imaginary space formed on the X, Y, and Z axes and wherein the feed current supplied to the power-fed antennas included in the antenna sets is supplied at a sequential phase difference of 90 deg each time it is switched from one of the four planes on which the antenna sets are provided to another.

33. The gate antenna device according to claim 31, wherein the antenna set is a loop antenna set comprising a power-fed loop antenna having a loop-like configuration to which a signal current is supplied and a non-power-fed loop antenna having a loop-like configuration to which no signal is supplied.

34. The antenna device according to claim 33, wherein a non-power-fed loop antenna having the greatest opening is provided at least on a plane along one axis among a plurality of planes in the imaginary space formed by the X, Y, and Z axes and wherein one or more loop antenna sets are provided on the planes along the remaining axes.

35. A gate antenna device having a plurality of antennas, wherein:

the plurality of antennas include a power-fed antenna to which a signal current is supplied and a non-power-fed antenna to which no signal current is supplied;

each of the plurality of antennas is provided on two or more planes in an imaginary space formed by X, Y, and X axes which are orthogonal to each other; and

the power-fed antenna is provided on at least one of the planes in the imaginary space and the non-power-fed antenna is provided on another of the planes.

36. The gate antenna device according to claim 35, wherein the antennas are provided on the planes in the imaginary space formed by the X, Y, and Z axes except one or more of the planes.

37. The gate antenna device according to claim 35, wherein:

a box-like body is formed in the imaginary space formed by the X, Y, and Z axes;

the plurality of antennas are provided on two or more planes of the box-like body; and

at least one of the plurality of antennas provided on the plane is the power-fed antenna, and another is the non-power-fed antenna.

38. The gate antenna device according to claim 37, wherein at least one of the planes of the box-like body is an open plane.

39. The gate antenna device according to claim 37, wherein the box-like body is a commodity case.

40. The gate antenna device according to claim 35, wherein the plurality of antennas are loop antennas having a loop-like configuration and wherein the plurality of loop antennas include a power-fed loop antenna to which a signal current is supplied and a non-power-fed loop antenna to which no signal current is supplied.

41. The gate antenna device according to claim 35, wherein a non-power-fed antenna having the greatest opening is provided at least on a plane along one axis among a plurality of planes in the imaginary space formed by the X, Y, and Z axes and wherein one or more of power-fed antennas and non-power-fed antennas are provided on the planes along the remaining axes.

42. The radio communication media processing apparatus comprising:

a gate antenna device having a plurality of antennas and communicating with a radio communication medium, the plurality of antennas including a power-fed antenna to which a signal current is supplied and a non-power-fed antenna to which no signal current is supplied;

a modulation unit for modulating data to be transmitted to the radio communication medium;

a demodulation unit for performing data demodulation on a signal from the radio communication medium received by the gate antenna device; and

a control unit for controlling the modulation unit and the demodulation unit.

43. The radio communication media processing apparatus according to claim 42, wherein the plurality of antennas are loop antennas having a loop-like configuration.

44. The radio communication media processing apparatus according to claim 42, wherein the plurality of antennas are provided on two or more planes in an imaginary space formed on X, Y, and Z axes which are orthogonal to each other.

45. The radio communication media processing apparatus according to claim 42, wherein the plurality of antennas are provided on two or more planes of a box-like body formed on the X, Y, and Z axes.

46. The radio communication media processing apparatus according to claim 42, comprising a determination unit for determining data demodulated by the demodulation unit.

47. The radio communication media processing apparatus according to claim 42, comprising an error detection unit for detecting an error in data demodulated by the demodulation unit.