MULTI-BAND ANTENNA

• US 20090256778A1
• Filed: 08/06/2008
• Published: 10/15/2009
• Est. Priority Date: 04/10/2008
• Status: Active Grant

• Current Assignee: PCTEL, Inc.
• Original Assignee: PCTEL, Inc.
• Inventors: Du, Xin
• Granted Patent: US 8,063,847 B2
• Time in Patent Office: Days
• US Class Current: 343/893
• CPC Class Codes: H01Q 1/38 formed by a conductive layer on an insulating support patch antennas H01Q9/0407; microstrip dipole antennas H01Q9/065; microstrip slot antennas H01Q13/106; transmission line microstrip antennas H01Q13/206; manufacturing reflecting surfaces using insulating material for supporting the reflecting surface H01Q15/142
• CPC Class Codes: H01Q 19/005 Patch antenna using one or more coplanar parasitic elements
• CPC Class Codes: H01Q 19/10 using reflecting surfaces
• CPC Class Codes: H01Q 19/32 the primary active element being end-fed and elongated
• CPC Class Codes: H01Q 21/24 Combinations of antenna units polarised in different directions for transmitting or receiving circularly and elliptically polarised waves or waves linearly polarised in any direction circularly polarised patch antennas H01Q9/0428; circularly polarised horns H01Q13/0241; cross-polarised horns H01Q13/0258; polarisation converters H01Q15/242; cross-polarised rear feeds H01Q19/136; crossed polarisation dual antenna H01Q25/001
• CPC Class Codes: H01Q 5/385 Two or more parasitic elements
• CPC Class Codes: H01Q 5/392 the parasitic elements having dual-band or multi-band characteristics

Abstract

A multi-band antenna is provided that operates in non-harmonically related frequency bands. The antenna includes a primary antenna element for a first frequency band of the non-harmonically related bands, said primary antenna element extending perpendicularly from a ground plane, the primary antenna element electrically isolated from the ground plane, a plurality of secondary elements extending from the ground plane parallel to the primary antenna element and arranged in a circle around the primary antenna element, each of said plurality of secondary elements electrically isolated from the primary antenna element and ground plane and a plurality of antenna elements for a second frequency band of a higher relative frequency than the first frequency band, the plurality of high frequency antenna elements extending parallel to the primary and secondary antenna elements and disposed in a circle around the secondary antenna elements.

Claims

1. A multi-band antenna that operates in non-harmonically related frequency bands, such antenna comprising:

a primary antenna element for a relatively low frequency band of the non-harmonically related bands, said primary antenna element extending from a ground plane, the primary antenna element electrically isolated from the ground plane;

a plurality of secondary antenna elements extending from the ground plane parallel to the primary antenna element and arranged in a circle with the plurality of secondary antenna elements each capacitively coupled to the primary antenna element and ground plane so as to electrically float between an electrical potential of the primary antenna element and ground plane;

a plurality of antenna elements for a relatively high frequency band of the non-harmonically related bands, said plurality of high frequency elements electrically isolated from the ground plane and extending parallel to the primary and secondary antenna elements, the plurality of high frequency elements arranged in a circle that surrounds the secondary antenna elements with the primary element disposed at the center of both circles.

2. The multi-band antenna of claim 1 further comprises a cross-member extending from a distal end of the primary element parallel to the ground plane.

3. The multi-band antenna of claim 1 further comprises a pair of mutually orthogonal cross-members extending from a distal end of the primary element parallel to the ground plane.

4. The multi-band antenna of claim 1 further comprising at least some of the secondary elements, at least some of the high frequency elements and the primary element are disposed in a straight line wherein the secondary elements reflect radiation from the high frequency elements.

5. The multi-band antenna of claim 1 wherein each of the plurality of high frequency elements further comprise a pair of parallel elements.

6. The multi-band antenna of claim 1 further comprising a plurality of support pads disposed adjacent the ground plane and arranged in a circle around the primary antenna element, each of the plurality of support pads electrically connected to and supporting a respective secondary antenna element of the plurality of secondary antenna elements.

7. The multi-band antenna of claim 6 further comprising a dielectric spacer disposed between each of the plurality of support pads and the ground plane to electrically isolate the support pads and secondary antenna elements from the ground plane.

8. The multi-band antenna of claim 7 wherein the dielectric spacer further comprises a printed circuit board with the primary element, plurality of secondary elements and plurality of high frequency elements disposed on a first side and the ground plane disposed on a second, opposing side.

9. The multi-band antenna of claim 1 further comprising a quarter wavelength low frequency ground connection with a length defined by a base frequency of the low frequency band connected between the primary antenna element and the ground plane.

10. The multi-band antenna of claim 1 further comprising a quarter wavelength high frequency ground connection with a length defined by a base frequency of the high frequency band connected between the high frequency elements and the ground plane.

11. A multi-band antenna that operates in non-harmonically related frequency bands, such antenna comprising:

a primary antenna element for a first frequency band of the non-harmonically related bands, said primary antenna element extending from a ground plane, the primary antenna element electrically isolated from the ground plane;

a plurality of secondary antenna elements electrically isolated from the primary antenna element extending from the ground plane parallel to the primary antenna element and arranged in a circle with the primary antenna element disposed at the center of the circle, each of said plurality of secondary antenna elements including a support pad disposed adjacent the ground plane that supports the secondary antenna element;

a dielectric spacer disposed between each of the plurality of support pads and the ground plane to electrically isolate the support pads and secondary antenna elements from the ground plane; and

a plurality of antenna elements for a second frequency band with a higher relative frequency than the first frequency band, the plurality of high frequency antenna elements extending parallel to the primary and secondary antenna elements and disposed in a circle with the primary antenna element located at the center of the circle of high frequency antenna elements.

12. The multi-band antenna as in claim 11 wherein the secondary antenna elements further comprise a length substantially equal to a quarter wavelength of a portion of the first frequency band.

13. The multi-band antenna as in claim 11 wherein the first frequency band further comprises 700-900 MHz.

14. The multi-band antenna as in claim 11 wherein the second frequency band further comprises 2.4-5.8 GHz.

15. A multi-band antenna that operates in non-harmonically related frequency bands, such antenna comprising:

a primary antenna element for a first frequency band of the non-harmonically related bands, said primary antenna element extending perpendicularly from a ground plane, the primary antenna element electrically isolated from the ground plane;

a plurality of secondary elements extending from the ground plane parallel to the primary antenna element and arranged in a circle around the primary antenna element, each of said plurality of secondary elements electrically isolated from the primary antenna element and ground plane; and

a plurality of antenna elements for a second frequency band of a higher relative frequency than the first frequency band, the plurality of high frequency antenna elements extending parallel to the primary and secondary antenna elements and disposed in a circle around the secondary antenna elements.

16. The multi-band antenna as in claim 15 further comprising a printed circuit board that supports the primary antenna element, the plurality of secondary antenna elements and the high frequency antenna elements on a first side of the printed circuit board and the ground plane disposed on a second, opposing side of the printed circuit board.

17. The multi-band antenna as in claim 16 further comprising a support pad for each respective secondary element disposed on the circuit board that capacitively couples the secondary element to the ground plane.

18. The multi-band antenna as in claim 16 wherein the support pads further comprise a respective arc extending at least partially around the primary element.

19. The multi-band antenna as in claim 16 further comprising a low frequency one-half wavelength ground shunt that connects the primary antenna element to the ground plane.

20. The multi-band antenna as in claim 16 further comprising a high frequency one-half wavelength ground shunt that connects the high frequency antenna elements to the ground plane.