Antenna coupler mechanism

• US 8,477,076 B1
• Filed: 01/25/2012
• Issued: 07/02/2013
• Est. Priority Date: 01/25/2012
• Status: Active Grant

• Current Assignee: Stryker Corporation
• Original Assignee: Clearcount Medical Solutions Incorporated (Stryker Corporation)
• Inventors: Nero, Regis J. Jr., Fleck, Steven J.
• Primary Examiner(s): Wimer, Michael C
• Assistant Examiner(s): ISLAM, HASAN Z
• Application Number:
  US13/358,168
• Publication Number:
  US 20130187758A1
• Time in Patent Office: 524 Days
• Field of Search: 340/572.7, 343/712, 343/713, 343/850, 343/860
• US Class Current: 343/850
• CPC Class Codes: G06K 19/07771 the record carrier comprising means for minimising adverse effects on the data communication capability of the record carrier, e.g. minimising Eddy currents induced in a proximate metal or otherwise electromagnetically interfering object
• CPC Class Codes: G06K 19/07786 the antenna being of the HF type, such as a dipole
• CPC Class Codes: G06K 7/10366 the interrogation device being adapted for miscellaneous applications
• CPC Class Codes: G08B 13/2437 Tag layered structure, processes for making layered tags
• CPC Class Codes: H01Q 1/22 by structural association with other equipment or articles
• CPC Class Codes: H01Q 1/2216 used in interrogator/reader equipment
• CPC Class Codes: H01Q 1/2225 used in active tags, i.e. provided with its own power source or in passive tags, i.e. deriving power from RF signal
• CPC Class Codes: H01Q 1/24 with receiving set
• CPC Class Codes: H01Q 1/245 with means for shaping the antenna pattern, e.g. in order to protect user against rf exposure
• 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 5/335 at the feed, e.g. for impedance matching
• 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 9/26 with folded element or elements, the folded parts being spaced apart a small fraction of operating wavelength resonant loop antennas H01Q7/00
• CPC Class Codes: Y10T 29/49018 with other electrical component

Abstract

Systems and methods are provided for an antenna coupler mechanism. The antenna coupler mechanism includes a first tuning leg configured to accept a radio frequency device. The first tuning leg includes a first inductive circuit element that is connected in series with the radio frequency device. The antenna coupler mechanism further includes a second tuning leg, which includes a second inductive circuit element and a capacitive circuit element connected in series. A bottom plate is connected in parallel with the first tuning leg and in parallel with the second tuning leg. The bottom plate comprises a third inductive circuit element and is configured to couple energy into a nearby structure.

Claims

1. An antenna coupler mechanism, comprising:

a first tuning leg comprising a first inductive circuit element, the first tuning leg being configured to accept a radio frequency device in series with the first inductive circuit element;

a second tuning leg comprising a second inductive circuit element and a capacitive circuit element connected in series, the second tuning leg being connected electrically in parallel with the first tuning leg; and

a bottom plate comprising a third inductive circuit element connected electrically in parallel with the first tuning leg and connected electrically in parallel with the second tuning leg, the bottom plate being configured to couple energy into a nearby structure;

wherein the bottom plate is positioned in a first plane, wherein the first tuning leg and the second tuning leg are positioned in a second plane, and wherein the first plane and the second plane are parallel planes.

2. The antenna coupler mechanism of claim 1, wherein the first inductive circuit element comprises a first two inductors connected in series, and wherein the second inductive circuit element comprises a second two inductors connected in series.

3. The antenna coupler mechanism of claim 1, wherein the nearby structure is a metallic object.

4. The antenna coupler mechanism of claim 1, wherein modifying an inductance value of the first inductive circuit element, an inductance value of the second inductive circuit element, or a capacitance value of the capacitive circuit element transforms an impedance formed by the antenna coupler mechanism.

5. The antenna coupler mechanism of claim 4, wherein the modifying maximizes energy coupling into the nearby structure by matching an impedance of the radio frequency device with an impedance of the nearby structure.

6. The antenna coupler mechanism of claim 1, wherein an inductance value of the first inductive circuit element is higher than an inductance value of the second inductive circuit element.

7. The antenna coupler mechanism of claim 1, wherein energy coupling between the bottom plate and the nearby structure is based on an area of the bottom plate, a distance between the bottom plate and the nearby structure, and a material occupying a volume between the bottom plate and the nearby structure.

8. The antenna coupler mechanism of claim 7, wherein the material is a dielectric material.

9. The antenna coupler mechanism of claim 8, wherein the dielectric material is an adhesive configured to connect the bottom plate with the nearby structure.

10. The antenna coupler mechanism of claim 7, wherein the material is air.

11. The antenna coupler mechanism of claim 1, wherein the first tuning leg, the second tuning leg, and the bottom plate are stacked vertically from the nearby structure.

12. The antenna coupler mechanism of claim 1, wherein the capacitor and the radio frequency device are located within a material separating the antenna coupler mechanism and the nearby structure.

13. The antenna coupler mechanism of claim 7, wherein, for a given capacitance value of the capacitive circuit element and a given set of inductance values for the first inductive circuit element, the second inductive circuit element, and the third inductive circuit element, an ideal distance exists, and wherein maximum energy coupling occurs between the bottom plate and the nearby structure at the ideal distance.

14. The antenna coupler mechanism of claim 1, wherein the antenna coupler mechanism is placed within a recess of the nearby structure.

15. The antenna coupler mechanism of claim 14, wherein the bottom plate is configured to face out of the recess.

16. The antenna coupler mechanism of claim 15, wherein the bottom plate of the antenna coupler mechanism is placed flush with a surface of the nearby structure.

17. The antenna coupler mechanism of claim 1, wherein the first inductive circuit element comprises a first two inductors connected in series, and wherein the second inductive circuit element comprises a second two inductors connected in series;

wherein an inductance value of the first inductive circuit element is higher than an inductance value of the second inductive circuit element; and

wherein energy coupling between the bottom plate and the nearby structure is based on a material occupying a volume between the bottom plate and the nearby structure, wherein the material is a dielectric adhesive configured to connect the bottom plate with nearby structure.

18. A method of coupling energy between a radio frequency device and a metallic object, comprising:

placing a bottom plate comprising a first inductive circuit element near a metallic object, the bottom plate being configured to couple energy into the metallic object;

connecting a first tuning leg electrically in parallel with the bottom plate, the first tuning leg comprising a second inductive circuit element;

connecting a second tuning leg electrically in parallel with the bottom plate and electrically in parallel with the first tuning leg, the second tuning leg comprising a third inductive circuit element and a capacitive circuit element connected in series;

incorporating a radio frequency device into the first tuning leg;

wherein the metallic object is configured to receive energy that is coupled from the radio frequency device via the bottom plate;

wherein the bottom plate is positioned in a first plane, wherein the first tuning leg and the second tuning leg are positioned in a second plane, and wherein the first plane and the second plane are parallel planes.

19. A system for determining a location of a metallic object, comprising:

an antenna coupler mechanism comprising;

a first tuning leg comprising a first inductive circuit element, the first tuning leg being configured to accept a radio frequency device in series with the first inductive circuit element;

a second tuning leg comprising a second inductive circuit element and a capacitive circuit element connected in series, the second tuning leg being connected electrically in parallel with the first tuning leg; and

a bottom plate comprising a third inductive circuit element connected electrically in parallel with the first tuning leg and connected electrically in parallel with the second tuning leg;

a radio frequency transceiver configured to send an interrogation signal to the radio frequency device and to receive a response signal originating from the radio frequency device; and

a metallic object connected to the antenna coupler mechanism, wherein the metallic object is configured to receive the response signal via the bottom plate, and wherein the metallic object is configured to transmit the response signal to the radio frequency transceiver;

wherein the bottom plate is positioned in a first plane, wherein the first tuning leg and the second tuning leg are positioned in a second plane, and wherein the first plane and the second plane are parallel planes.