Radio frequency antenna for an object interrogation device comprising a radio frequency antenna associated with an electronic circuit

• US 6,894,660 B2
• Filed: 06/12/2002
• Issued: 05/17/2005
• Est. Priority Date: 12/16/1999
• Status: Expired due to Fees

• Current Assignee: Tagsys SA
• Original Assignee: Tagsys SA
• Inventors: Sanogo, Lassina
• Primary Examiner(s): Ho, Tan
• Application Number:
  US10/167,793
• Publication Number:
  US 20020186175A1
• Time in Patent Office: 1,070 Days
• Field of Search: 343/741, 343/742, 343/866, 343/867, 343/895, 343/787, 343/788, 340/551, 340/572.2, 235/492
• US Class Current: 343/895
• CPC Class Codes: G06K 19/0724 the arrangement being a circuit for communicating at a plurality of frequencies, e.g. for managing time multiplexed communication over at least two antennas of different types
• 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 1/2216 used in interrogator/reader equipment
• CPC Class Codes: H01Q 1/36 Structural form of radiating elements, e.g. cone, spiral, umbrella; Particular materials used therewithH01Q1/08, H01Q1/14 take precedence
• 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 7/08 Ferrite rod or like elongated core
• CPC Class Codes: H01Q 9/27 Spiral antennas

Abstract

A transmission/reception radio-wave aerial for an interrogation device for electronic labels carried by objects, the transmission/reception radio-wave aerial being tuned to an F0 frequency and each electronic label including a radio-wave aerial tuned to the F0 frequency and being associated with an electronic circuit, wherein the transmission/reception radio-wave aerial is arranged to create a magnetic field which modifies the tuning frequency for the radio-wave aerials for the electronic labels in such a way to retune towards the F0 frequency of the aerial of the interrogation device.

Claims

1. A transmission/reception radio-wave aerial for an interrogation device for electronic labels carried by objects, the transmission/reception radio-wave aerial being tuned to an F0 frequency and each electronic label including a radio-wave aerial tuned to the F0 frequency and being associated with an electronic circuit, wherein the transmission/reception radio-wave aerial is arranged to create a magnetic field which modifies the tuning frequency for the radio-wave aerials for the electronic labels in such a way to retune towards the F0 frequency of the aerial of the interrogation device.

2. The aerial according to claim 1, wherein the transmission/reception radio-wave aerial is suitable for creating the magnetic field whose force lines are substantially perpendicular to the plane of the aerials in the electronic labels.

3. The aerial according to claim 2, wherein the aerial for the interrogation device includes a substantially planar winding including a plurality of turns the width (W) of which is larger than their spacing (S).

4. The aerial according to claim 3, characterized in that width (W) of a turn is at least one order of magnitude greater than the spacing.

5. The aerial according to claim 2, wherein the aerial for the interrogation device includes a winding including a plurality of turns wound around a support made of ferrite.

6. The aerial according to claim 5, wherein the turns have a spacing (S) which is greater than their diameter (D).

7. The aerial according to claim 6, wherein the spacing (S) between two consecutive turns is at least one order of magnitude larger than their diameter (D).

8. The aerial according to claim 1, wherein the aerial for the interrogation device includes a winding including a plurality of turns wound around a support made of ferrite.

9. The aerial according to claim 8, wherein the turns have a spacing (s) which is greater than their diameter (D).

10. The aerial according to claim 9, wherein the spacing (S) between two consecutive turns is at least one order of magnitude larger than their diameter (D).

11. The aerial according to claim 1, wherein the measurements of the interrogation device aerial are determined by the maximum distance between the aerial and the aerials for the objects as well as by the measurements of the electronic labels.

12. The aerial according to claim 1, wherein the surface area of the aerial of the interrogation device is around one order of magnitude greater than that of the electronic label aerial.

13. An electronic label interrogation device comprising a transmission/reception aerial as claimed in claim 1.

14. A transmission/reception radio-wave aerial for an interrogation device for electronic labels carried by objects, the transmission/reception radio-wave aerial being tuned to an F0 frequency and each electronic label including a radio-wave aerial tuned to the F0 frequency and being associated with an electronic circuit, wherein the transmission/reception radio-wave aerial is arranged to create a magnetic field which modifies the tuning frequency for the radio-wave aerials for the electronic labels in such a way to retune towards the F0 frequency of the aerial of the interrogation device, wherein the aerial for the interrogation device includes a substantially planar winding including a plurality of turns the width (W) of which is larger than their spacing (S).

15. The aerial according to claim 14, characterized in that width (W) of a turn is at least one order of magnitude greater than the spacing.

16. A transmission/reception radio-wave aerial for an interrogation device for electronic labels carried by objects comprising:

a dielectric support;

a conductor winding having at least two terminal connections fixed to the dielectric support; and

an electronic circuit connected between the terminal connections and tuned to an F0 frequency,

wherein current passing through the conductor winding creates a magnetic field which modifies tuning frequencies for radio-wave aerials for other electronic labels to retune towards the F0 frequency of the aerial of the interrogation device.