Tracking apparatus, system and method

• US 7,183,922 B2
• Filed: 10/06/2004
• Issued: 02/27/2007
• Est. Priority Date: 03/18/2002
• Status: Active Grant

• Current Assignee: NXP USA, Inc. (NXP Semiconductors NV)
• Original Assignee: Paratek Microwave Incorporated (Blackberry Limited)
• Inventors: Mendolia, Greg, Kvarnstrand, John, du Toit, Nicolaas, Foo, Bing, du Toit, Cornelis
• Primary Examiner(s): Wu; Daniel
• Assistant Examiner(s): Mehmood; Jennifer
• Application Number:
  US10/959,562
• Publication Number:
  US 20050110674A1
• Time in Patent Office: 874 Days
• Field of Search: 3405721-5729, 340/505, 340/506, 340/539.13, 343/911.R, 343/726, 343/748, 343/855, 343866-872, 700213-244, 705/22, 235375-385
• US Class Current: 340/572.1
• CPC Class Codes: G01S 13/878 Combination of several spaced transmitters or receivers of known location for determining the position of a transponder or a reflector G01S13/874 takes precedence
• CPC Class Codes: G01S 5/04 Position of source determined by a plurality of spaced direction-finders
• CPC Class Codes: G01S 5/12 by co-ordinating position lines of different shape, e.g. hyperbolic, circular, elliptical or radial
• CPC Class Codes: G06K 7/10079 the collision being resolved in the spatial domain, e.g. temporary shields for blindfolding the interrogator in specific directions
• CPC Class Codes: G06K 7/10336 the antenna being of the near field type, inductive coil
• CPC Class Codes: G06K 7/10346 the antenna being of the far field type, e.g. HF types or dipoles
• CPC Class Codes: H01Q 1/42 Housings not intimately mechanically associated with radiating elements, e.g. radome
• CPC Class Codes: H01Q 21/205 providing an omnidirectional coverage turnstile aerials H01Q21/26
• CPC Class Codes: H01Q 25/00 Antennas or antenna systems providing at least two radiating patterns arrangements for changing or varying the orientation or the shape of the directional pattern H01Q3/00
• CPC Class Codes: H01Q 3/36 with variable phase-shifters
• CPC Class Codes: H01Q 9/0407 Substantially flat resonant element parallel to ground plane, e.g. patch antenna dipole H01Q9/285; monopole H01Q9/40

Abstract

An apparatus capable of tracking a target, comprising at least one near-field focused antenna comprising an array of elements and a phase shifter to form multiple fixed beams in the near-field, a sensor capable of sensing the location of the target, and a controller capable of accepting position information and capable of activating the proper fixed beam along a course so as to enable the near-field focused beams to track the target. The array of elements may be substantially linear and the sensor may be optical, mechanical, thermal, or sonic position detection subsystems.

Claims

1. An apparatus for tracking a RFID Tag comprising:

at least one near-field focused antenna comprising an array of element and a beamformer to form multiple fixed beams in the near-field, wherein said beamformer includes at least one phase shifter that includes a voltage tunable dielectric capacitor for focusing beams;

a sensor adpapted to sense the position of said Tag; and

a controller adpapted to accept position information and adapted to activate the proper fixed beam along a course so as to enable the near-field focused beams to track said Tag.

2. The apparatus of claim 1, wherein said array of elements is substantially linear.

3. The apparatus of claim 1, wherein said sensor is one or more selected from the following group:

optical, mechanical, thermal, or sonic position detection subsystems.

4. The apparatus of claim 1, wherein said controller controls a plurality of switches which activate at least one beam forming network.

5. The apparatus of claim 1, wherein said tracking occurs along a predetermined course.

6. The apparatus of claim 5, wherein said predetermined course is along a conveyor line.

7. An apparatus adapted to tracking a RFID Tag comprising:

an array of elements;

a beamformer adapted to form multiple fixed beams in the near-field, wherein said beamformer includes at least one phase shifter that includes a voltage tunable dielectric canacitor for focusing said beams;

a sensor adapted to sense the location of said Tag; and

a controller adapted to accept location information and activate the proper fixed beam so as to enable near-field focused beams to track said Tag.

8. The apparatus of claim 7, wherein said tracking occurs along a predetermined course.

9. The apparatus of claim 7, wherein said sensor is one or more selected from the following group:

optical, mechanical, thermal, or sonic position detection subsystems.

10. The apparatus of claim 7, wherein said array of elements is substantially linear.

11. A system for tracking a RFID Tag comprising:

at least one near-field focused antenna comprising a set of transmit arrays, wherein each array includes a set of elements arranged substantially in an arc, wherein said are lies in a plane substantially normal to the direction of motion of said Tag;

a beemform for each transmit array adapted to form at least one fixed beam in us near-field, wherein said beamformer includes at least one phase shifter that includes a voltage tunable dielectric capacitor for focusing beams;

a sensor adapted to determine the position of said Tag; and

a controller adapted to accept positiam information and adapted to activate the proper fixed beam so as to enable the near-field flied beams to track the Tag.

12. The apparatus of claim 11, wherein said sensor is one or more selected from the following group:

optical, mechanical, thermal, or sonic position detection subsystems.

13. The apparatus of claim 11, wherein said target is at least one RFID tag.

14. The apparatus of claim 11, wherein said tracking occurs along a predetermined course.

15. The apparatus of claim 14, wherein said predetermined course is along a conveyor line.

16. A method of tracking a RFID Tag comprising:

forming multiple fixed beams in the near-field with at least one near-field focused antenna comprising an array of elements and a phase stifter, wherein the formation of beams involves the use of at least one said phase shifter that includes a voltage tunable dielectric capacitor for focusing beams;

sensing the location of said Tag with a sensor; and

accepting location information by a controller adapted to activate the proper fixed beam along a course so as to enable the near-field focused beams to track said Tag.

17. The method of claim 16, further comprising placing said array of elements in a substantially linear manner.

18. The method of claim 16, further comprising selecting said sensor from the following group:

optical, mechanical, thermal, or sonic position detection subsystems.

19. The method of claim 16, further comprising controlling by said ontroller a plurality of switches which activate at least one beam forming network.

20. The method of claim 16, further comprising tracking along a predetermined course.

21. A system for tracking a RFID Tag comprising:

a conveyor adapted to move staid Tag within a near field focused antenna comprising an are of transmit antenna arrays, wherein said are lies in a plane substantially normal to the direction of motion of said Tag;

a beamformer for each transmit array adapted to form at least one fixed beam in its

near-field, wherein said beamformer includes at least one phase shifter that includes a

voltage tunable dielectric capacitor for focusing beams;

a sensor adapted to determine the position of said Tag; and

a controller adapted to accept position information and adapted to activate the proper fixed beam so as to enable the near-field focused beams to track the Tag.