Method, dual rectangular patch antenna system and radio for providing isolation and diversity

• US 5,486,836 A
• Filed: 02/16/1995
• Issued: 01/23/1996
• Est. Priority Date: 02/16/1995
• Status: Expired due to Term

• Current Assignee: Quarterhill Inc. (f/k/a Wi-LAN Inc.)
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Kuffner, Stephen L., Carney, Scott N., Krenz, Eric L.
• Primary Examiner(s): Hajec, Donald T.
• Assistant Examiner(s): Ho, Tan
• Application Number:
  US08/389,540
• Time in Patent Office: 341 Days
• Field of Search: 343/700 MS, 343/702, 343/725, 343/830, 343/846, 343/844, 343/853, 343/876
• US Class Current: 343/700.0MS
• CPC Class Codes: H01Q 1/243 with built-in antennas
• CPC Class Codes: H01Q 1/525 between emitting and receiving antennas
• CPC Class Codes: H01Q 3/24 varying the orientation by switching energy from one active radiating element to another, e.g. for beam switching

Abstract

The present invention provides a method, dual rectangular patch antenna system, and radio for providing isolation and diversity while eliminating the need for a diplexer or a second transmit/receive switch. The dual rectangular patch antenna system comprises a first rectangular patch antenna (202), a second rectangular patch antenna (204), and a switch (206). Receive path diversity is provided by switching between the first rectangular patch antenna (202) and the second rectangular patch antenna (204).

Claims

1. A dual rectangular patch antenna system for providing isolation and diversity comprising:

A) a first rectangular patch antenna having a substantially planar conductive rectangular first patch with four coplanar sides, a first midline orthogonal to a first side, and a second midline parallel to the first side and intersecting the first midline at a center of the first patch, wherein the first patch includes;

A1) a first mode feedpoint, located on the first midline between the first side and the center of the first patch, for providing a first mode polarization, wherein the first mode feedpoint is connected to a transmit path; and

A2) a second mode feedpoint, located on the second midline between a second side, adjacent to the first side, and the center of the first patch, for providing a second mode polarization orthogonal to the first mode polarization, wherein the first mode feedpoint and the second mode feedpoint are located such that an isolation is provided by a voltage null of the first mode polarization along the second midline and a voltage null of the second mode polarization along the first midline;

B) a second rectangular patch antenna, spatially separated from the first rectangular patch antenna, having a substantially planar conductive rectangular second patch including a third mode feedpoint for providing a third mode polarization; and

C) a switch, operably coupled to select one of the second mode feedpoint of the first rectangular patch antenna and the third mode feedpoint of the second rectangular patch antenna based on a predetermined signal quality, for providing spatial diversity in a receive path.

2. The dual rectangular patch antenna system of claim 1, wherein the third mode polarization is orthogonal to the first mode polarization to provide signal isolation between a transmit and a receive path in a full-duplex system.

3. The dual rectangular patch antenna system of claim 1, wherein the third mode polarization is orthogonal to the second mode polarization to provide polarization diversity in the receive path.

4. The dual rectangular patch antenna system of claim 1, wherein the second patch has four coplanar sides, a third midline orthogonal to a first side of the second patch, and a fourth midline parallel to the first side of the second patch and intersecting the third midline at a center of the second patch, the second patch includes:

B1) the third mode feedpoint, located on the third midline between the first side of the second patch and the center of the second patch, for providing a third mode polarization; and

B2) a fourth mode feedpoint, located on the fourth midline between a second side, adjacent to the first side, of the second patch and the center of the second patch, for providing a fourth mode polarization orthogonal to the third mode polarization, wherein the third mode feedpoint and the fourth mode feedpoint are located such that an isolation is provided by a voltage null of the third mode polarization along the fourth midline and a voltage null of the fourth mode polarization along the third midline.

5. The dual rectangular patch antenna system of claim 4, wherein the system further comprises a second switch, operably coupled to select one of the first mode feedpoint of the first rectangular patch antenna and the fourth mode feedpoint of the second rectangular patch antenna based on a second predetermined signal quality, for providing spatial diversity in the transmit path.

6. A method for providing isolation and diversity comprising:

A) providing, by a first feed point on a first rectangular patch antenna, a first mode polarization connected to a transmit path;

B) providing, by a second feedpoint on the first rectangular patch antenna, a second mode polarization orthogonal to the first mode polarization and isolated from the first mode polarization;

C) providing, by a third feedpoint on a second rectangular patch antenna, a third mode polarization, wherein in the second rectangular patch antenna is spatially separated from the first rectangular patch antenna; and

D) providing, by a switch, a selection of one of the second mode polarization and the third mode polarization based on a predetermined signal quality to provide spatial diversity in a receive path.

7. The method of claim 6, wherein the third mode polarization is orthogonal to the first mode polarization to provide signal isolation between the transmit path and the receive path in a full-duplex system.

8. The method of claim 6, wherein the third mode polarization is orthogonal to the second mode polarization to provide polarization diversity in the receive path.

9. The method of claim 6, wherein the method further comprises:

E) providing, by a fourth feedpoint on the second rectangular patch antenna, a fourth mode polarization orthogonal to the third mode polarization and isolated from the third mode polarization; and

F) providing, by a second switch, a selection of one of the first mode polarization and the fourth mode polarization based on a second predetermined signal quality to provide spatial diversity in the transmit path.

10. A dual rectangular patch antenna system for providing isolation and diversity comprising:

A) a first rectangular patch antenna having a substantially planar conductive rectangular first patch with four coplanar sides, a first midline orthogonal to a first side, and a second midline parallel to the first side and intersecting the first midline at a center of the first patch, wherein the first patch includes;

A1) a first mode feedpoint, located on the first midline between the first side and the center of the first patch, for providing a first mode polarization, wherein the first mode feedpoint is connected to a transmit path; and

A2) a second mode feedpoint, located on the second midline between a second side, adjacent to the first side, and the center of the first patch, for providing a second mode polarization orthogonal to the first mode polarization, wherein the first mode feedpoint and the second mode feedpoint are located such that an isolation is provided by a voltage null of the first mode polarization along the second midline and a voltage null of the second mode polarization along the first midline;

B) a second rectangular patch antenna, spatially separated from the first rectangular patch antenna, having a substantially planar conductive rectangular second patch with four coplanar sides, a third midline orthogonal to a first side of the second patch, and a fourth midline parallel to the first side of the second patch and intersecting the third midline at a center of the second patch, wherein the second patch includes;

B1) the third mode feedpoint, located on the third midline between the first side of the second patch and the center of the second patch, for providing a third mode polarization; and

B2) a fourth mode feedpoint, located on the fourth midline between a second side, adjacent to the first side, of the second patch and the center of the second patch, for providing a fourth mode polarization orthogonal to the third mode polarization, wherein the third mode feedpoint and the fourth mode feedpoint are located such that an isolation is provided by a voltage null of the third mode polarization along the fourth midline and a voltage null of the fourth mode polarization along the third midline;

C) a first switch, operably coupled to select one of the second mode feedpoint of the first rectangular patch antenna and the third mode feedpoint of the second rectangular patch antenna based on a predetermined signal quality, for providing spatial diversity in a receive path; and

D) a second switch, operably coupled to select one of the first mode feedpoint of the first rectangular patch antenna and the fourth mode feedpoint of the second rectangular patch antenna based on a second predetermined signal quality, for providing spatial diversity in the transmit path.

11. The dual rectangular patch antenna system of claim 10, wherein the second mode polarization is orthogonal to the third mode polarization to provide polarization diversity in the receive path.

12. The dual rectangular patch antenna system of claim 10, wherein the first mode polarization is orthogonal to the fourth mode polarization to provide polarization diversity in the transmit path.

13. A method for providing isolation and diversity comprising:

A) providing, by a first feedpoint on a first rectangular patch antenna, a first mode polarization connected to a transmit path;

B) providing, by a second feedpoint on the first rectangular patch antenna, a second mode polarization orthogonal to the first mode polarization and isolated from the first mode polarization;

C) providing, by a third feedpoint on a second rectangular patch antenna, a third mode polarization, wherein in the second rectangular patch antenna is spatially separated from the first rectangular patch antenna; and

D) providing, by a fourth feedpoint on the second rectangular patch antenna, a fourth mode polarization orthogonal to the third mode polarization and isolated from the third mode polarization;

E) providing, by a first switch, a selection of one of the second mode polarization and the third mode polarization based on a predetermined signal quality to provide spatial diversity in a receive path; and

F) providing, by a second switch, a selection of one of the first mode polarization and the fourth mode polarization based on a second predetermined signal quality to provide spatial diversity in the transmit path.

14. The method of claim 13, wherein the second mode polarization is orthogonal to the third mode polarization to provide polarization diversity in the receive path.

15. The method of claim 13, wherein the first mode polarization is orthogonal to the fourth mode polarization to provide polarization diversity in the transmit path.

16. A radio having a dual rectangular patch antenna system for providing isolation and diversity, the dual rectangular patch antenna system comprising:

A) a first rectangular patch antenna having a substantially planar conductive rectangular first patch with four coplanar sides, a first midline orthogonal to a first side, and a second midline parallel to the first side and intersecting the first midline at a center of the first patch, wherein the first patch includes;

A1) a first mode feedpoint, located on the first midline between the first side and the center of the first patch, for providing a first mode polarization, wherein the first mode feedpoint is connected to a transmit path; and

A2) a second mode feedpoint, located on the second midline between a second side, adjacent to the first side, and the center of the first patch, for providing a second mode polarization orthogonal to the first mode polarization, wherein the first mode feedpoint and the second mode feedpoint are located such that an isolation is provided by a voltage null of the first mode polarization along the second midline and a voltage null of the second mode polarization along the first midline;

B) a second rectangular patch antenna, spatially separated from the first rectangular patch antenna, having a substantially planar conductive rectangular second patch with four coplanar sides, a third midline orthogonal to a first side of the second patch, and a fourth midline parallel to the first side of the second patch and intersecting the third midline at a center of the second patch, wherein the second patch includes;

B1) the third mode feedpoint, located on the third midline between the first side of the second patch and the center of the second patch, for providing a third mode polarization; and

B2) a fourth mode feedpoint, located on the fourth midline between a second side, adjacent to the first side, of the second patch and the center of the second patch, for providing a fourth mode polarization orthogonal to the third mode polarization, wherein the third mode feedpoint and the fourth mode feedpoint are located such that an isolation is provided by a voltage null of the third mode polarization along the fourth midline and a voltage null of the fourth mode polarization along the third midline;

C) a first switch, operably coupled to select one of the second mode feedpoint of the first rectangular patch antenna and the third mode feedpoint of the second rectangular patch antenna based on a predetermined signal quality, for providing spatial diversity in a receive path; and

D) a second switch, operably coupled to select one of the first mode feedpoint of the first rectangular patch antenna and the fourth mode feedpoint of the second rectangular patch antenna based on a second predetermined signal quality, for providing spatial diversity in the transmit path.