Integrated artificial magnetic launch surface for near field communication system

• US 10,389,410 B2
• Filed: 06/29/2017
• Issued: 08/20/2019
• Est. Priority Date: 06/29/2017
• Status: Active Grant

• Current Assignee: Texas Instruments, Inc.
• Original Assignee: Texas Instruments, Inc.
• Inventors: Brooks, Nathan, Cook, Benjamin Stassen, Sankaran, Swaminathan, Kramer, Bradley Allen, Morgan, Mark W., Haroun, Baher S
• Primary Examiner(s): Trinh, Tan H
• Application Number:
  US15/638,163
• Publication Number:
  US 20190007103A1
• Time in Patent Office: 782 Days
• Field of Search: 455 411, 455 412
• CPC Class Codes: H01Q 5/321 within a radiating element or between connected radiating elements
• CPC Class Codes: H01Q 5/40 Imbricated or interleaved structures; Combined or electromagnetically coupled arrangements, e.g. comprising two or more non-connected fed radiating elements
• CPC Class Codes: H04B 5/22 Capacitive coupling
• CPC Class Codes: H04B 5/48 Transceivers
• CPC Class Codes: H04B 5/77 for interrogation
• CPC Class Codes: H04B 5/79 for data transfer in combination with power transfer

Abstract

A system is provided in which a set of modules each have a substrate on which is mounted a radio frequency (RF) transmitter and/or an RF receiver coupled to a near field communication (NFC) coupler located on the substrate. Each module has a housing that surrounds and encloses the substrate. The housing has a port region on a surface of the housing. Each module has a field confiner located between the NFC coupler and the port region on the housing configured to guide electromagnetic energy emanated from the NFC coupler through the port region to a port region of an adjacent module. An artificial magnetic conductor surface is positioned adjacent the backside of each NFC coupler to reflect back side electromagnetic energy with a phase shift of approximately zero degrees.

Claims

1. A module comprising:

a near field communication (NFC) coupler having a front side and an opposite back side;

a radio frequency (RF) transmitter coupled to the NFC coupler, the RF transmitter configured to generate an RF signal having a frequency;

a substrate on which the NFC coupler is located and on which the RF transmitter is mounted;

an artificial magnetic conductor (AMC) surface, proximate the back side of the NFC coupler and separated from the NFC coupler by less than one fourth of a wavelength of the RF signal, the AMC surface positioned to reflect near-field electromagnetic energy having the frequency of the RF signal with essentially zero phase shift; and

a field confiner, proximate the front side of the NFC coupler, the field confiner located to propagate and/or evanescently couple near-field electromagnetic energy emanated from the NFC coupler.

2. The module of claim 1, wherein the AMC surface includes a first conductive layer and a second conductive layer separated by a dielectric layer, the first conductive layer is patterned into an array of isolated conductive region, and the second conductive layer is coupled to a ground reference for the RF transmitter.

3. The module of claim 2, wherein the substrate is a first substrate, and the AMC surface is formed in a second substrate that is separate from the first substrate.

4. The module of claim 1, further comprising:

a housing that surrounds and encloses the substrate and the AMC surface, the housing having a port region on a surface of the housing;

wherein the field confiner is proximate the front side of the NFC coupler between the NFC coupler and the port region of the housing, the field confiner being located to propagate and/or evanescently couple near-field electromagnetic energy emanated from the NFC coupler through the port region.

5. The module of claim 4, wherein the field confiner fills a gap between the port region of the surface of the housing and the NFC coupler.

6. The module of claim 5, wherein the port region is offset laterally from the NFC coupler, and the field confiner is skewed to fill the gap between the port region of the surface of the housing and the NFC coupler.

7. The module of claim 1, wherein the field confiner is a dielectric block having a relative permittivity greater than approximately 1.0.

8. The module of claim 1, wherein the field confiner is a negative index metamaterial.

9. The module of claim 1, wherein an electromagnetic field emanated from the NFC coupler has a frequency in the range of approximately 5-100 GHz.

10. The module of claim 1, wherein the field confiner has a conductive sidewall.

11. A module comprising:

a first near field communication (NFC) coupler having a front side and an opposite back side;

a second NFC coupler having a front side and an opposite back side;

a radio frequency (RF) transmitter coupled to the first NFC coupler;

an RF communication circuit coupled to the second NFC coupler;

a substrate on which the first and second NFC couplers are located and on which the RF transmitter and the RF communication circuit are mounted;

a first artificial magnetic conductor (AMC) surface proximate the back side of the first NFC coupler;

a first field confiner, proximate the front side of the first NFC coupler, located to propagate and/or evanescently couple near-field electromagnetic energy emanated from the first NFC coupler;

a second AMC surface proximate the back side of the second NFC coupler; and

a second field confiner, proximate the front side of the second NFC coupler, located to propagate and/or evanescently couple near-field electromagnetic energy to the RF communication circuit.

12. The module of claim 11, wherein the second AMC surface includes a first conductive layer and a second conductive layer separated by a dielectric layer, the first conductive layer is patterned into an array of isolated conductive region, and the second conductive layer is coupled to a ground reference for the RF receiver.

13. The module of claim 12, wherein the second conductive layer of the first AMC surface and the second conductive layer of the second AMC surface are the same layer.

14. The module of claim 11, further comprising:

a housing that surrounds and encloses the substrate and the first AMC surface and the second AMC surface, the housing having a first port region on a first surface of the housing and a second port region on a second surface of the housing;

wherein the first field confiner is proximate the front side of the first NFC coupler between the first NFC coupler and the first port region of the housing, the first field confiner being located to propagate and/or evanescently couple near-field electromagnetic energy emanated from the first NFC coupler through the first port region; and

wherein the second field confiner is proximate the front side of the second NFC coupler between the second NFC coupler and the second port region of the housing, the second field confiner being located to propagate and/or evanescently couple near-field electromagnetic energy from the second port region to the second NFC coupler.

15. The module of claim 11, further comprising:

a backplane; and

a plurality of modules attached to the backplane, wherein each of the modules has a respective first port region and a respective second port region;

wherein the first port region of a first one of the modules aligns with the second port region of an adjacent second one of the modules.

16. A module comprising:

a plurality of transmitters and/or receivers;

a first near field communication (NFC) coupler having a front side and an opposite back side, the first NFC coupler coupled to at least one of the transmitters and/or receivers;

a second NFC coupler coupled to at least one of the transmitters and/or receivers;

a substrate on which the first and second NFC couplers are located and on which the transmitters and/or receivers are mounted;

an artificial magnetic conductor (AMC) surface proximate the back side of the first NFC coupler and proximate the second NFC coupler; and

a field confiner, proximate the front side of the first NFC coupler, located to propagate and/or evanescently couple near-field electromagnetic energy emanated from the first NFC coupler.

17. A method of transmitting a signal in a system, the method comprising:

generating a first radio frequency (RF) signal in a module;

emanating a first RF electromagnetic field in response to the first RF signal from a first near field communication (NFC) coupler in the module;

reflecting a portion of the emanated first RF electromagnetic field using a first artificial magnetic conductor (AMC) surface located proximate the first NFC coupler, such that the reflected portion is not phase shifted;

confining and directing the emanated first RF electromagnetic field and the reflected portion of the emanated first RF electromagnetic field by a first field confiner to a first port region in the module;

generating a second radio frequency (RF) signal in the module;

emanating a second RF electromagnetic field in response to the second RF signal from a second NFC coupler in the module;

reflecting a portion of the emanated second RF electromagnetic field using a second AMC surface located proximate the second NFC coupler, such that the reflected portion is not phase shifted; and

confining and directing the emanated second RF electromagnetic field and the reflected portion of the emanated second RF electromagnetic field by a second field confiner to a second port region in the module.

18. The method of claim 17, wherein the module is a first module, and the method further comprises:

receiving the emanated first RF electromagnetic field and the reflected portion of the emanated first RF electromagnetic field by a third field confiner in a second module located adjacent the first module;

coupling the emanated first RF electromagnetic field and the reflected portion of the emanated first RF electromagnetic field to a third NFC coupler in the second module; and

providing a resultant RF signal to an RF receiver on the second module.