Wireless communication device having multiband antenna

• US 6,762,723 B2
• Filed: 11/08/2002
• Issued: 07/13/2004
• Est. Priority Date: 11/08/2002
• Status: Active Grant

• Current Assignee: Google Technology Holdings LLC (Alphabet Inc.)
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Faraone, Antonio, Nallo, Carlo Di
• Primary Examiner(s): Ho, Tan
• Application Number:
  US10/291,305
• Publication Number:
  US 20040090372A1
• Time in Patent Office: 613 Days
• Field of Search: 343/700.MS, 343/702, 343/767, 343/872, 455/89, 455/90
• US Class Current: 343/700.0MS
• CPC Class Codes: H01Q 1/243 with built-in antennas
• CPC Class Codes: H01Q 5/357 using a single feed point
• CPC Class Codes: H01Q 9/0421 with a shorting wall or a shorting pin at one end of the element H01Q9/0414 takes precedence
• CPC Class Codes: H01Q 9/0442 with particular tuning means
• CPC Class Codes: H01Q 9/0457 electromagnetically coupled to the feed line

Abstract

The invention provides antenna systems (102, 900, 2300, 2800) for wireless communication devices that make efficient use of space while supporting multi-band operation. The antenna systems comprise elongated flat conductors (206,406,902,1206,1508,1304,1902,2000,2100,2302,2500,2600,2702,2802,2902), supported spaced from finite ground planes (202, 914, 1910). The antenna systems are capable of operating in a symmetric common mode, an anti-symmetric differential mode, and a slot mode.

Claims

1. A wireless communication device comprising:

an antenna system comprising;

a finite ground surface, wherein the ground surface comprises a ground plane;

an elongated conductor that is characterized by a length and is spaced from the finite ground surface, wherein the elongated conductor follows a path in a virtual plane, wherein the virtual plane is tilted with respect to the ground plane, wherein the elongated conductor is supported on the ground plane by a truncated wedge shaped dielectric spacer, wherein the elongated conductor comprises a slot that extends through a substantial portion of the length of the elongated conductor;

a grounding conductor coupling the finite ground surface to the elongated conductor;

a signal feed conductor coupling to the elongated conductor, and

a housing with a tapered portion for accommodating the elongated conductor supported on the truncated wedge shaped dielectric spacer.

2. A wireless communication device comprising:

an antenna system comprising;

a finite ground surface;

an elongated conductor that is characterized by a length and is spaced from the finite ground surface, wherein the elongated conductor follows a path in a surface that curves in three dimensional space;

wherein the elongated conductor comprises;

a slot that extends through a substantial portion of the length of the elongated conductor;

a grounding conductor coupling the finite ground surface to the elongated conductor; and

a signal feed conductor coupling to the elongated conductor; and

a housing including a portion that complements the shape of the surface.

3. A wireless communication device comprising:

an antenna system comprising;

a finite ground surface;

an elongated conductor that is characterized by a length and is spaced from the finite ground surface, wherein the elongated conductor includes;

a first end;

a second end;

a side edge; and

slot that extends through a substantial portion of the length of the elongated conductor;

a grounding conductor coupling the finite ground surface to the elongated conductor, wherein the grounding conductor connects to the side edge at a first point that is between the first end and the second end; and

a signal feed conductor coupling to the elongated conductor, wherein the signal feed conductor connects to the same side edge at a second point of the elongated conductor that is between the first end and the second end; and

wherein the first point and the second point are within a middle ½

longitudinal portion of the elongated conductor.

4. The wireless communication device according to claim 3 wherein:

the first point and the second point are separated by between 4 and 30 millimeters.

5. The wireless communication device according to claim 3 further comprising:

a capacitive tab that extends from the elongated conductor, between signal feed conductor and the grounding conductor toward the finite ground surface.

6. A wireless communication device comprising:

an antenna system comprising;

a finite ground surface;

an elongated conductor that is characterized by a length and is spaced from the finite ground surface, wherein the elongated conductor comprises;

a slot that extends through a substantial portion of the length of the elongated conductor;

a grounding conductor coupling the finite ground surface to the elongated conductor; and

a signal feed conductor coupling to the elongated conductor,

wherein a first capacitance enhancing clement is located proximate a first end of the elongated conductor for establishing a first capacitance between the elongated conductor and the finite ground surface;

wherein a second capacitance element located proximate a second end of the elongated conductor for establishing a second capacitance between the elongated conductor and the finite ground surface;

and wherein the first capacitance differs from the second capacitance.

7. A wireless communication device comprising:

an antenna system comprising;

a finite ground surface;

an elongated conductor that is characterized by a length and is spaced from the finite ground surface, wherein the elongated conductor comprises;

a slot that extends through a substantial portion of the length of the elongated conductor; and

an elongated flat conductor;

wherein the elongated flat conductor is separated from the ground surface by a congruently shaped dielectric spacer;

a grounding conductor coupling the finite ground surface to the elongated conductor;

a signal feed conductor coupling to the elongated conductor; and

one or more capacitive tabs extending from the elongated flat conductor toward the finite ground surface.

8. The wireless communication device according to claim 7 wherein:

the elongated flat conductor is U-shaped.

9. A wireless communication device comprising:

an antenna system comprising;

a finite ground surface;

an elongated conductor that is characterized by a length and is spaced from the finite ground surface, wherein the elongated conductor includes;

a first end,

a second end,

a point intermediate the first end and the second end; and

a slot that extends through a substantial portion of the length of the elongated conductor;

a grounding conductor coupling the finite sound surface to the elongated conductor; and

a signal feed conductor coupling to the elongated conductor; and

a communication circuit coupled to the signal feed conductor, wherein the communication circuit is capable of processing signals at a first frequency, a second frequency and a third frequency; and

wherein the antenna system supports;

a first common mode, at the first frequency, in which at any given instant current summed over the cross section of the elongated conductor passes in the elongated conductor in opposite directions in longitudinal sections that are on opposite sides of the point;

a second differential mode, at the second frequency, in which at any given instant current runs in a common direction on the elongated conductor; and

a third slot mode, at the third frequency, in which at any given instant current runs in opposite directions on opposite sides of the slot.

10. The wireless communication device according to claim 9 wherein:

the slot is between one-quarter and one times a free space wavelength associated with the third frequency.

11. The wireless communication device according to claim 10 wherein:

the slot is between one-half and three-quarters the free space wavelength.

12. A wireless communication device comprising:

an antenna system comprising;

a finite ground surface;

an elongated conductor that is characterized by a length and is spaced from the finite ground surface, wherein the elongated conductor includes;

a first end,

a second end,

a point intermediate the first end and the second end, and

a slot that extends through a substantial portion of the length of the elongated conductor;

grounding conductor coupling the finite ground surface to the elongated conductor; and

a signal feed conductor coupling to the elongated conductor; and

a communication circuit coupled to the antenna system wherein the communication circuit is capable of processing signals at a first frequency, a second frequency and a third frequency;

wherein the antenna system supports;

a common electromagnetic mode, at the first frequency, in which at any given time electric field vectors between the elongated conductor and the finite ground surface on both sides of the point, point in substantially the same direction;

a differential electromagnetic mode, at the second frequency, in which at any given time, electric field vectors between the elongated conductor and the finite ground surface on a first side of the point are opposite in phase relative to electrical field vectors between the elongated conductor and the finite ground surface on a second side of the point; and

a slot electromagnetic mode, at the third frequency, in which a substantial fraction of electromagnetic field energy is associated with an electric field including electric field lines that cross the slot.

13. The wireless communication device according to claim 12 wherein:

the elongated conductor comprises an inner edge, and an outer edge;

wherein;

the outer edge is between about one-eighth and one-half times a first free space wavelength associated with the first frequency;

the inner edge is between about one-eighth and one times a second free space wavelength associated with the second frequency.

14. The wireless communication device according to claim 13 wherein:

the outer edge is between one-quarter and one-half the first free space wavelength;

the inner edge is between about one-quarter and one-half the second free space wavelength.

15. A wireless communication device comprising:

an antenna system comprising;

a finite ground surface;

an elongated conductor that is characterized by a length and is spaced from the finite ground surface, wherein the elongated conductor comprises;

a slot that extends through a substantial portion of the length of the elongated conductor;

a grounding conductor coupling the finite ground surface to the elongated conductor; and

a signal feed conductor coupling to the elongated conductor;

a multi-layer circuit;

wherein the finite ground surface includes one layer of the multi-layer circuit;

a housing enclosing the multi-layer circuit and the elongated conductor; and

a plurality of components located adjacent the elongated conductor;

wherein at least a portion of the elongated conductor follows a convoluted contour to accommodate placement of one or more of the plurality of components.

16. A wireless communication device comprising:

an antenna system comprising;

a finite ground surface;

an elongated conductor that is characterized by a length and is spaced from the finite ground surface, wherein at least a substantial portion of the elongated conductor follows a substantially U shaped contour, wherein the elongated conductor comprises a slot that extends through a substantial portion of the length of the elongated conductor;

a grounding conductor coupling the finite ground surface to the elongated conductor; and

a signal feed conductor coupling to the elongated conductor.

17. The wireless communication device according to claim 16 further comprising

a multi-layer circuit; wherein the finite ground surface includes one layer of the multi-layer circuit; and

one or more components are located on the multi-layer circuit within the U shaped contour of the elongated conductor.

18. A wireless communication device comprising:

an antenna system comprising;

a finite ground surface;

an elongated conductor that is characterized by a length and is spaced from the finite ground surface, wherein wherein the elongated conductor comprises;

a slot that extends through a substantial portion of the length of the elongated conductor; and

a capacitive gap on one side of the slot;

a grounding conductor coupling the finite ground surface to the elongated conductor; and

a signal feed conductor coupling to the elongated conductor.

19. A wireless communication device comprising:

an antenna system comprising;

a finite ground surface;

an elongated conductor that is characterized by a length and is spaced from the finite ground surface, wherein the elongated conductor comprises;

a slot that extends through a substantial portion of the length of the elongated conductor; and

one or more shorts across the slot;

a grounding conductor coupling the finite ground surface to the elongated conductor; and

a signal feed conductor coupling to the elongated conductor.

20. A wireless communication device comprising:

an antenna system comprising;

a finite ground surface;

an elongated conductor that is characterized by a length and is spaced from the finite ground surface, wherein the elongated conductor comprises;

a slot that extends through a substantial portion of the length of the elongated conductor;

a grounding conductor coupling the finite ground surface to the elongated conductor; and

a signal feed conductor coupling to the elongated conductor; and

a housing having a curved edge;

wherein the elongated conductor is supported on and conforms to the curved edge.