COUPLED ANTENNA STRUCTURE AND METHODS

• US 20140253393A1
• Filed: 03/11/2013
• Published: 09/11/2014
• Est. Priority Date: 03/11/2013
• Status: Active Grant

• Current Assignee: Cantor Fitzgerald Securities (Cantor Fitzgerald, L.P.)
• Original Assignee: Pulse Finland Oy (Yageo Corporation)
• Inventors: Nissinen, Pertti, Koskiniemi, Kimmo, Ramachandran, Prasadh
• Granted Patent: US 10,079,428 B2
• Time in Patent Office: Days
• US Class Current: 343/702
• CPC Class Codes: H01Q 1/273 Adaptation for carrying or wearing by persons or animals
• 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 5/385 Two or more parasitic elements
• 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 7/005 with variable reactance for tuning the antenna
• CPC Class Codes: H01Q 9/0421 with a shorting wall or a shorting pin at one end of the element H01Q9/0414 takes precedence

Abstract

Antenna apparatus and methods of use and tuning. In one exemplary embodiment, the solution of the present disclosure is particularly adapted for small form-factor, metal-encased applications that utilize satellite wireless links (e.g., GPS), and uses an electromagnetic (e.g., capacitive) feeding method that includes one or more separate feed elements that are not galvanically connected to a radiating element of the antenna. In addition, certain implementations of the antenna apparatus offer the capability to carry more than one operating band for the antenna.

Claims

1. Coupled antenna apparatus, comprising:

a plurality of antenna radiating elements, the plurality comprising;

a first radiating element;

a second radiating element proximate to the first element; and

a third radiating element proximate to the second element; and

wherein the first, second, and third elements are each electromagnetically coupled with one or more of the other elements of the plurality, and cooperate to provide a circular polarization substantially optimized for receipt of positioning asset wireless signals.

2. The apparatus of claim 1, wherein the first element comprises an outer element proximate an outer surface of a host device, the second element comprises a middle element, and the third element comprises a feed element substantially internal to the host device.

3. The apparatus of claim 2, wherein at least one of (i) a width of the outer element and (ii) a distance of the outer element from the middle element are selected based at least in part on a desired frequency operating band and an operating bandwidth.

4. The apparatus of claim 1, wherein the electromagnetic coupling comprises capacitive coupling, and the first element, second element, and the third element are not galvanically coupled.

5. The apparatus of claim 1, wherein the second element is comprised of first and second sub-elements, each of the sub elements corresponding to a different frequency band.

6. The apparatus of claim 5, further comprising a short circuit point connecting the second radiator element to a ground.

7. The apparatus of claim 6, wherein placement of the short circuit point determines at least in part a resonant frequency of the coupled antenna apparatus.

8. The apparatus of claim 7, wherein the third element comprises a ground point and a galvanically connected feed point.

9. The apparatus of claim 8, wherein the placement of the ground point with respect to the feed point determines at least in part a resonant frequency of the coupled antenna apparatus.

10. The apparatus of claim 8, wherein the placement of at least the feed point and ground point affects at least one of a right-handed circular polarization (RHCP) and/or left-handed circular polarization (LHCP) isolation gain.

11. Capacitively coupled antenna apparatus, comprising a plurality of substantially stacked radiators configured to have a right-handed circular polarization (RHCP) isolation gain that is substantially greater than a left-handed circular polarization (LHCP) isolation gain thereof, thereby enhancing sensitivity to satellite positioning signals.

12. The apparatus of claim 11, wherein the plurality of substantially stacked radiator elements are stacked along an axis that is generally correspondent to a direction from which the satellite signals are to be received.

13. The apparatus of claim 11, wherein the plurality of substantially stacked radiator elements comprise first, second, and third elements, wherein the first element comprises an outer element proximate an outer metallic housing of a host device, the second element comprises a middle element, and the third element comprises a feed element substantially internal to the host device.

14. The apparatus of claim 11, wherein the plurality of radiator elements are not galvanically coupled to one another.

15. The apparatus of claim 11, further comprising switching apparatus configured to switch at least a feed point associated with one of the plurality of substantially stacked radiators so as to produce a left-handed circular polarization (LHCP) isolation gain that is substantially greater than the right-handed circular polarization (RHCP) isolation gain thereof.

16. A method of tuning a coupled antenna apparatus having at least first, second, and third radiating elements, the method comprising:

selecting at least one of (i) a width of the outer element and (ii) a distance of the first element from the second element based at least in part on a desired frequency operating band and an operating bandwidth of the antenna apparatus; and

selecting placement of a short circuit point connecting the second radiator element to a ground so as to determines at least in part a resonant frequency of the coupled antenna apparatus.

17. The method of claim 16, wherein the third element comprises a ground point and a galvanically connected feed point, and the method further comprises selecting a placement of the ground point with respect to the feed point so as to determine at least in part a resonant frequency of the coupled antenna apparatus.

18. Satellite positioning-enabled wireless apparatus, comprising:

a wireless receiver configured to at least receive satellite positioning signals; and

antenna apparatus in signal communication with the receiver, the antenna apparatus comprising;

a stacked configuration comprising an outer radiator element, at least one middle radiator element disposed internal to the outer element, and an inside feed element, the inside feed element further configured to be galvanically coupled with a feed point, and the at least one middle radiator element configured to be electromagnetically coupled to the inside feed element.

19. The wireless apparatus of claim 18, wherein dimensions of the outer radiator element, the at least one middle radiator element, and feed element are selected such that their resonance frequency values are substantially proximate to one another, and a larger bandwidth is cooperatively achieved.

20. The wireless apparatus of claim 18, further comprising an at least partly metallic outer housing.

21. The wireless apparatus of claim 20, wherein the outer radiator element is comprised of the at least partly metallic outer housing.

22. The wireless apparatus of claim 18, wherein at least one of the outer and at least one middle radiator elements comprise a laser direct structured (LDS) structure.