Antenna embedded inventory shelf

• US 10,140,483 B1
• Filed: 09/24/2014
• Issued: 11/27/2018
• Est. Priority Date: 06/17/2014
• Status: Active Grant

• Current Assignee: Amazon Technologies, Inc. (Amazon.com, Inc.)
• Original Assignee: Amazon Technologies, Inc. (Amazon.com, Inc.)
• Inventors: Huebner, Ronald Eugene, Niranjayan, Somasundaram, McKinnon, Mark Glen
• Primary Examiner(s): Trail, Allyson
• Application Number:
  US14/495,838
• Time in Patent Office: 1,525 Days
• Field of Search: 235493, 235385, 235492, 235488, 235439, 343843
• 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: G06K 7/10415 the interrogation device being fixed in its position, such as an access control device for reading wireless access cards, or a wireless ATM banking machines in general G07F19/00
• CPC Class Codes: G06K 7/10465 the interrogation device being capable of self-diagnosis, e.g. in addition to or as part of the actual interrogation process testing of electrical circuits in general G01R31/28
• CPC Class Codes: G06Q 10/087 Inventory or stock management, e.g. order filling, procurement or balancing against orders
• CPC Class Codes: H01Q 1/2216 used in interrogator/reader equipment
• CPC Class Codes: H01Q 1/40 Radiating elements coated with or embedded in protective material

Abstract

This disclosure describes the ability to efficiently track inventory using RFID tags (e.g., RFID tags). For example, an inventory shelf located within a materials handling facility may include a series of antenna elements arranged in rows embedded into the shelf that are coupled with an RFID reader. The antenna elements are configured to establish electromagnetic fields oriented along shelf rows. The fields can be used to read RFID tags included or attached to inventory items placed on the shelf row.

Claims

1. An apparatus, comprising:

an antenna embedded inventory shelf, including;

a ground plane;

a substrate positioned on top of and adjacent to the ground plane and formed of a material having a low dielectric constant;

a plurality of antenna elements positioned along an upper surface of the substrate such that a radio frequency identification (“

RFID”

) tag placed near an antenna element of the plurality of antenna elements will be energized by the antenna element; and

a protective cover positioned over the plurality of antenna elements, such that the plurality of antenna elements are positioned between the substrate and the protective cover.

2. The apparatus of claim 1, wherein each of the plurality of antenna elements are planar radiating transmission lines.

3. The apparatus of claim 1, wherein the ground plane is a gondola shelf.

4. The apparatus of claim 1, wherein the substrate comprises at least one of polyvinyl chloride, polystyrene, acrylonitrile butadiene styrene, high-density polyethylene, or low-density polyethylene.

5. The apparatus of claim 1, further comprising:

a plurality of load resistors, each of the plurality of load resistors terminating a respective antenna element.

6. The apparatus of claim 1, further comprising:

an RFID reader coupled to each of the plurality of antenna elements and configured to energize at least one of the plurality of antenna elements; and

a multiplexer coupled between the RFID reader and each of the plurality of antenna elements.

7. The apparatus of claim 6, wherein the multiplexer, in response to an input from the RFID reader, selects one or more of the plurality of antenna elements such that the selected one or more of the plurality of antenna elements are energized.

8. The apparatus of claim 6, wherein the multiplexer is incorporated into the RFD reader.

9. The apparatus of claim 1, further comprising:

a plurality of matching circuits, each matching circuit coupled to a respective antenna element of the plurality of antenna elements.

10. The apparatus of claim 1, wherein the protective cover is formed of a porous material configured to provide a separation between the plurality of antenna elements and an inventory item placed on the protective cover.

11. The apparatus of claim 1, wherein the protective cover is configured to reduce a detuning caused by an inventory item placed on the protective cover.

12. An apparatus comprising:

a ground plane;

a substrate formed of a material having a low dielectric constant and positioned on top of and adjacent the ground plane, the substrate configured to support a plurality of inventory items;

a plurality of antenna elements positioned along an upper surface of the substrate such that a radio frequency identification (“

RFID”

) tag placed near an antenna element of the plurality of antenna elements will be energized by the antenna element; and

a protective cover positioned over the plurality of antenna elements, such that the plurality of antenna elements are positioned between the substrate and the protective cover.

13. The apparatus of claim 12, further comprising:

wherein the substrate comprises a material having a low dielectric constant to increase a field strength above a surface of the apparatus for each of the plurality of antenna elements.

14. The apparatus of claim 12, wherein the plurality of antenna elements are at least partially embedded into the substrate.

15. The apparatus of claim 12, wherein at least two of the plurality of antenna elements are substantially parallel to each other and extend from a rear of the substrate toward a front of the substrate.

16. The apparatus of claim 12, wherein each of the plurality of antenna elements are planar radiating transmission lines.

17. The apparatus of claim 12, further comprising:

a field emanating from each of the antenna elements; and

wherein each field overlaps at least one other field.

18. The apparatus of claim 17, wherein each field emanates between approximately two inches and approximately six inches above a surface of the apparatus.

19. The apparatus of claim 12, further comprising:

a plurality of load resistors, each of the plurality of load resistors positioned at an end of an antenna element and having a characteristic impedance substantially similar to an impedance of the antenna element.

20. The apparatus of claim 12, wherein the ground plane is a metal shelf of an existing shelf system.

21. An apparatus, comprising:

a substrate having a low dielectric constant and configured to support an inventory item;

an antenna element positioned along a surface of the substrate such that a tag identifier corresponding to the inventory item will be received by the antenna element when the inventory item is placed near the antenna element; and

a protective cover positioned over the antenna element, such that the antenna element is positioned between the substrate and the protective cover.

22. The apparatus of claim 21, further comprising:

a second antenna element positioned along the surface of the substrate.

23. The apparatus of claim 21, further comprising:

a ground plane; and

wherein the substrate is positioned on top of and adjacent the ground plane.

24. The apparatus of claim 21, further comprising:

a reader coupled to the antenna element and configured to energize the antenna element and receive the tag identifier from the antenna element.