ANTENNA DESIGN AND INTERROGATOR SYSTEM

• US 20110121945A1
• Filed: 06/11/2009
• Published: 05/26/2011
• Est. Priority Date: 06/12/2008
• Status: Active Grant

• Current Assignee: SATO Holdings Corporation
• Original Assignee: SATO Vicinity Pty Limited (SATO Holdings Corporation)
• Inventors: Littlechild, Stuart Colin, Vaichas, Aras, Murdoch, Graham Alexander Munro
• Granted Patent: US 8,810,371 B2
• Time in Patent Office: Days
• US Class Current: 340/10.1
• CPC Class Codes: G06K 7/0008 General problems related to the reading of electronic memory record carriers, independent of its reading method, e.g. power transfer
• CPC Class Codes: G06K 7/10346 the antenna being of the far field type, e.g. HF types or dipoles

Abstract

Where a single cable conveys bidirectional RF signals and bidirectional data using a data carrying DC power signal where the RF signals and the bidirectional data carrying DC power signal are separated using frequency selective networks. Alternatively a single cable conveys bidirectional RF signals and bidirectional data using a modulated RF data signal where the RF signals and the bidirectional modulated RF data signal are separated using frequency selective networks. A array of switchable antennas where RF switching elements are integral to the antennas is connected to the single cable and is powered by and communicated with through the cable. The array of switchable antennas can be arranged to produce an interrogation field in any of one, two or three dimensions by the antennas being arranged to provide for a series of parallel spaced conductors through which currents are sequentially switched in order to produce both tangential and normal magnetic field components. The spatial relationship of the sequentially switched currents is chosen to ensure that at different times a tangential and a normal magnetic field are produced at the same location. The conductors are preferably arranged in a planar fashion and the tangential and normal magnetic fields are produced above the planar surface. A single layer of parallel spaced conductors provides for one or two dimensional operations. Adding a second parallel layer of orthogonally oriented parallel spaced conductors provides three dimensional operations where currents are sequentially switched in both layers.

Claims

1. A communication method for enabling communication between a first device and a second device, the method comprising:

providing a first signal representing a radio frequency (RF) signal;

providing a second signal representing a power signal;

providing a third signal representing at least one of a control signal and a data signal;

providing a communication path for carrying the first, second and third signals; and

wherein the third signal is carried on the second signal.

4. The method as claimed in claim 1, wherein the communication is unidirectional.

5. The method as claimed in claim 1, wherein the communication is bidirectional.

6. The method as claimed in claim 1, wherein the first device is an reader.

7. The method as claimed in claim 1, wherein the second device is at least one of a multiplexer (MUX) and at least one antenna.

8. The method as claimed in claim 1, wherein at least one of the first and second devices are used in radio frequency identification (RFID).

9. The method as claimed in claim 1, wherein the second signal is a DC power signal.

10. The method as claimed in claim 1, wherein the first signal is separated electrically from the second and third signals using frequency selective networks.

11. The method as claimed in claim 1, wherein the second device comprises at least one of a memory device, a logic device and a microcontroller connected to the communication path and is powered by and communicated with through the communication path.

12. The method as claimed in claim 1, wherein the second device comprises a RF MUX connected to the communication path and is powered by and communicated with through the communication path.

13. The method as claimed in claim 1, wherein the second device comprises an array of antennas connected to the communication path and is powered by and communicated with through the communication path.

14. The method as claimed in claim 1, wherein the second device comprises a plurality of antennas or an array of antennas, each of which is less than ½

the size of the array, in order to reduce radiation emission.

15. The method as claimed in claim 13, wherein RF switching elements are provided to switch any one or any combination of antennas in the array.

16. The method as claimed in claim 15, wherein the switching elements are configured to enable an interrogation field in any of one, two or three dimensions to be produced

17. The method as claimed in claim 16, wherein the antennas are arranged to provide for a series of parallel spaced conductors through which currents are sequentially switched in order to produce both tangential and normal magnetic field components.

21. The method as claimed in claim 17, wherein a second parallel layer of orthogonally oriented parallel spaced conductors is provided and which provides three dimensional operations where currents are sequentially switched in both layers.

24. A multiplexer (MUX) adapted for communication according to claim 1.

25. A reader adapted for communication according to the method of claim 1.

2-3. -3. (canceled)

18-20. -20. (canceled)

22-23. -23. (canceled)

26. A method of coupling a first device to a second device, the method comprising:

providing a communication path between the first and second devices;

providing an identification attribute in at least one of the first and second device;

communicating the identification attribute between the first and second devices; and

determining from the communication path whether the first and second devices are correctly coupled.

27-35. -35. (canceled)