COMPACT POLARIZED ANTENNA AND METHODS

• US 20130265199A1
• Filed: 04/04/2012
• Published: 10/10/2013
• Est. Priority Date: 04/04/2012
• Status: Active Grant

• Current Assignee: Pulse Finland Oy (Yageo Corporation)
• Original Assignee: Cantor Fitzgerald Securities (Cantor Fitzgerald, L.P.)
• Inventors: Koskiniemi, Kimmo, Nissinen, Pertti
• Granted Patent: US 8,988,296 B2
• Time in Patent Office: Days
• US Class Current: 342/450
• CPC Class Codes: G01S 19/14 specially adapted for specific applications
• CPC Class Codes: H01Q 1/273 Adaptation for carrying or wearing by persons or animals
• CPC Class Codes: H01Q 9/0428 radiating a circular polarised wave
• CPC Class Codes: H01Q 9/045 with particular feeding means for circular polarisation H01Q9/0428
• CPC Class Codes: H01Q 9/42 with folded element, the folded parts being spaced apart a small fraction of the operating wavelength
• CPC Class Codes: Y10T 29/49016 Antenna or wave energy "plumbing" making

Abstract

A right-hand circular polarized antenna and associated methods. In one embodiment, a quarter-wave antenna configuration is used within a small form factor portable device (e.g. wristwatch). The antenna comprises a radiator element which operates in as a linear polarized antenna while the device is operating in free space. However, when the device is attached to a user (e.g. at a user'"'"'s wrist), the antenna utilizes the loading of the user'"'"'s body tissue in order to suppress unwanted signals (e.g. left hand polarized signals) to permit operation in circular polarized mode (e.g. right hand polarized mode), thereby allowing for increased sensitivity to received circularly polarized signals such as those emanated from global positioning satellites.

Claims

1. An antenna component for use in a portable communications device, the device comprising a ground, a feed port, and a ground plane, said component comprising:

a dielectric substrate;

a radiator element disposed proximate to a surface of said substrate; and

a feed conductor configured to couple to the radiator at a feed point;

wherein said antenna component is configured to operate in a first mode when placed under a first operating condition, and to operate in a second mode when placed under a second operating condition.

2. The antenna component of claim 1, wherein said first mode comprises operating as a linear polarized antenna, and said second mode comprises operating as a right hand circular polarized (RHCP) antenna.

3. The antenna component of claim 2, wherein the first operating condition comprises said device operating in free-space and said second operating condition comprises said device operating under a loading condition.

4. The antenna component of claim 3, wherein said loading condition comprises said device being in electrical contact with at least a part of a user'"'"'s body.

5. The antenna component of claim 1, wherein the antenna component comprises a quarter-wave antenna.

6. The antenna component of claim 1, further comprising a ground conductor configured to couple to the radiator at a ground point.

7. The antenna component of claim 1, wherein the feed port is coupled to a ground point of the device, the coupling occurring at a point between the feed point and the ground point.

8. A small form factor portable device configured to provide positioning information to a user thereof, the device comprising:

an antenna capable of operating in a free-space mode and a non free-space mode; and

positioning receiver circuitry capable of extracting data from received circularly polarized signals received via at least the non free-space mode of the antenna, the data useful in determining the position of the device.

9. The device of claim 8, wherein the device comprises a wristwatch-like form factor having a substantially planar face, and the antenna is disposed so as to provide maximal sensitivity in a direction substantially normal to the planar face.

10. The device of claim 9, wherein the antenna comprises a quarter-wave antenna, thereby allowing said device form factor to be smaller than it would otherwise without use of the quarter wave antenna.

11. The device of claim 9, wherein the antenna comprises no high-dielectric (high Epsilon) materials.

12. The device of claim 8, wherein the free-space mode comprises a mode wherein the device is not in direct contact with a user thereof, and the non free-space mode comprises a mode wherein the device is loaded by at least contact of the device with bodily tissue of the user.

13. The device of claim 8, wherein the antenna comprises a substantially polymeric three-dimensional base member and at least one layer of conductive material disposed over prescribed portions of a surface thereof.

14. The device of claim 13, wherein the at least one layer of conductive material is formed using a laser direct structuring (LDS) technique.

15. A quarter-wave antenna apparatus for use in small form factor portable electronic device applications, the apparatus formed by the method comprising:

providing a three-dimensional polymer-based structure;

applying at least one layer of conductive material to selected regions of a surface of the structure so as to produce a quarter-wave radiator, portions of said selected regions corresponding to a feed and a ground for said radiator;

wherein placement of the feed portion and ground portion are selected so as produce desired right-handed circular polarization (RHCP) and left-handed circular polarization (LHCP) isolation gains.

16. The apparatus of claim 15, wherein the placement of the feed portion and ground portion are selected so as produce desired right-handed circular polarization (RHCP) and left-handed circular polarization (LHCP) isolation gains is selected so as to provide an RHCP isolation gain which is substantially greater than an LHCP isolation gain.

17. The apparatus of claim 15, wherein the three-dimensional polymer-based structure comprises a substantially arcuate shape.

18. The apparatus of claim 15, wherein the applying at least one layer of conductive material to selected regions of a surface of the structure comprises use of a laser direct structuring process.

19. The apparatus of claim 15, wherein the applying at least one layer of conductive material to selected regions of a surface of the structure comprises use of a printing process using flowable conductive material, and without any plating process.

20. A method of tuning an antenna so as to optimize the relationship of a first polarization and a second polarization, the antenna comprising a layer of conductive material disposed on a three-dimensional substrate, the method comprising selecting the position of at least one of a feed trace and a ground trace on the three-dimensional substrate so as to control an isolation gain for the first polarization relative to the second polarization.

21. The method of claim 20, wherein the first polarization comprises a right-handed circular polarization (RHCP) and the second polarization comprises a left-handed circular polarization (LHCP).

22. The method of claim 20, further comprising adjusting a relative positional relationship of the feed trace and ground trace so as to achieve a desired input impedance for the antenna.

23. A method of tuning an antenna so as to optimise an input impedance thereof, the antenna comprising a layer of conductive material disposed on a three-dimensional substrate, the method comprising selecting the position of at least one of a feed trace and a ground trace on the three-dimensional substrate so as to control the input impedance.