Claims
- 1. A difference drive diversity antenna structure comprising:
- a first antenna, having a radiation pattern with a first polarization;
- a second antenna, proximate to the first antenna, having a first radiating element tuned to a first frequency band, a second radiating element tuned to a second frequency band different from the first frequency band, a third radiating element tuned to the first frequency band, and a fourth radiating element tuned to the second frequency band, aligned parallel to the first antenna, having a radiation pattern with a second polarization, different from the first polarization; and
- a phase shifter for differentially driving the first radiating element and the second radiating element out of phase relative to the third radiating element and the fourth radiating element.
- 2. A difference drive diversity antenna structure according to claim 1 wherein the phase shifter differentially drives the first radiating element and the second radiating element 180 degrees out of phase relative to the third radiating element and the fourth radiating element.
- 3. A difference drive diversity antenna structure according to claim 1 wherein the phase shifter differentially drives the first radiating element, the second radiating element, the third radiating element, and the fourth radiating element at the same magnitude.
- 4. A difference drive diversity antenna structure according to claim 1 wherein the phase shifter is a balun.
- 5. A difference drive diversity antenna structure according to claim 1 wherein the phase shifter is a transmission line.
- 6. A difference drive diversity antenna structure according to claim 1 wherein the first radiating element comprises:
- a slot.
- 7. A difference drive diversity antenna structure according to claim 6 wherein the second radiating element comprises:
- a slot.
- 8. A difference drive diversity antenna structure according to claim 7 wherein the first radiating element and the second radiating element are driven by a single differential port.
- 9. A difference drive diversity antenna structure according to claim 7 wherein the third radiating element comprises:
- a slot.
- 10. A difference drive diversity antenna structure according to claim 9 wherein the fourth radiating element comprises:
- a slot.
- 11. A difference drive diversity antenna structure according to claim 10 wherein the third radiating element and the fourth radiating element are driven by a single differential port.
- 12. A difference drive diversity antenna structure according to claim 1 wherein the first radiating element comprises:
- an inverted F structure having a leg and a first radiator.
- 13. A difference drive diversity antenna structure according to claim 12 wherein the second radiating element comprises:
- an inverted F structure having the leg and a second radiator.
- 14. A difference drive diversity antenna structure according to claim 13 wherein the first radiating element and the second radiating element are driven by a single differential port.
- 15. A difference drive diversity antenna structure according to claim 1 wherein the first radiating element comprises:
- a multi-layer compact slot.
- 16. A difference drive diversity antenna structure according to claim 15 wherein the second radiating element comprises:
- a multi-layer compact slot.
- 17. A difference drive diversity antenna structure according to claim 16 wherein the first radiating element and the second radiating element are driven by a single differential port.
- 18. A radiotelephone comprising:
- a first antenna aligned parallel to a major axis of the radiotelephone, having a radiation pattern with a first polarization;
- a second antenna having a first radiating element tuned to a first frequency band, a second radiating element tuned to a second frequency band different from the first frequency band, a third radiating element tuned to the first frequency band, and a fourth radiating element tuned to the second frequency band, aligned parallel to the first antenna, having a radiation pattern with a second polarization different from the first polarization; and
- a phase shifter for differentially driving the first radiating element and the second radiating element out of phase relative to the third radiating element and the fourth radiating element.
- 19. A radiotelephone according to claim 18 wherein the phase shifter differentially drives the first radiating element and the second radiating element 180 degrees out of phase relative to the third radiating element and the fourth radiating element.
- 20. A method for driving a diversity antenna structure comprising:
- aligning a first antenna, having a radiation pattern with a first polarization, parallel to an axis of a communication device;
- positioning a second antenna, having a first radiating element tuned to a first frequency band, a second radiating element tuned to a second frequency band different from the first frequency band, a third radiating element tuned to the first frequency band, and a fourth radiating element tuned to the second frequency band, and a second polarization different from the first polarization, parallel to the axis; and
- differentially driving the first radiating element and the second radiating element out of phase relative to the third radiating element and the fourth radiating element using a single differential port.
- 21. A method for driving a diversity antenna structure according to claim 20 further comprising the step of:
- driving the first radiating element and the second radiating element 180 degrees out of phase relative to the third radiating element and the fourth radiating element.
- 22. A method for driving a diversity antenna structure according to claim 20 further comprising the step of:
- driving the first radiating element, the second radiating element, the third radiating element, and the fourth radiating element at the same magnitude.
CROSS REFERENCE TO RELATED APPLICATIONS
This application is related to application Ser. No. 08/854,197 entitled "Multi-Layered Compact Slot Antenna Structure and Method" by David R. Haub, Louis J. Vannatta, and Hugh K. Smith (Attorney Docket No. CE01551R) filed same date herewith, the specification of which is incorporated herein by reference. This application is also related to application Ser. No. 08/854,282 entitled "Multi-Band Slot Antenna Structure and Method" by Louis J. Vannatta and Hugh K. Smith (Attorney Docket No. CE01548R) filed same date herewith, the specification of which is incorporated herein by reference.
US Referenced Citations (8)
Foreign Referenced Citations (4)
Number |
Date |
Country |
0 036 139 A2 |
Sep 1981 |
EPX |
0 749 216 A1 |
Dec 1996 |
EPX |
WO8502719 |
Jun 1985 |
WOX |
WO 9102386 A1 |
Feb 1991 |
WOX |