Feed network

• US 20040056819A1
• Filed: 09/23/2002
• Published: 03/25/2004
• Est. Priority Date: 09/23/2002
• Status: Active Grant

• Current Assignee: PCTEL, Inc.
• Original Assignee: Maxrad Incorporated
• Inventors: McCarthy, Robert Daniel, Fix, Russell Alan
• Granted Patent: US 6,788,272 B2
• Time in Patent Office: Days
• US Class Current: 343/850
• CPC Class Codes: H01Q 11/08 Helical antennas

Abstract

An antenna feed network including a 180° hybrid coupler having a feed port, a 0° port; and a 180° port having an approximately 180° phase difference with the 0° port. A first antenna port is coupled to the 0° port; and a second antenna port is coupled to the 0° port via a respective phased line, the second antenna port having an approximately 90° phase difference with the first antenna port. A third antenna port is coupled to the 180° port; and a fourth antenna port is coupled to the 180° port via a respective phased line, the fourth antenna port having an approximately 90° phase difference with the third antenna port. The feed network can be used to drive antenna elements in phase quadrature. In a preferred embodiment the feed network drives a quadriflar helix antenna.

Claims

1. An antenna feed network including:

a 180°

hybrid coupler having a feed port, a 0°

port; and

a 180°

port having an approximately 180°

phase difference with the 0°

port;

a first antenna port coupled to the 0°

port;

a second antenna port coupled to the 0°

port via a respective phased line, the second antenna port having an approximately 90°

phase difference with the first antenna port;

a third antenna port coupled to the 180°

port; and

a fourth antenna port coupled to the 180°

port via a respective phased line, the fourth antenna port having an approximately 90°

phase difference with the third antenna port.

2. The network of claim 1 wherein the hybrid coupler is a microstrip hybrid coupler.

3. The network of claim 1 wherein the hybrid coupler is deposited on a dielectric substrate.

4. The network of claim 3 wherein a ground plane is deposited on an opposite side of said dielectric substrate.

5. The network of claim 1, wherein the hybrid coupler is a ring hybrid.

6. The network of claim 1, wherein the hybrid coupler has no terminated port.

7. An antenna including:

a 180°

hybrid coupler having a feed element, a 0°

port; and

a 180°

port having an approximately 180°

phase difference with the 0°

element;

a first antenna element coupled to the 0°

port;

a second antenna element coupled to the 0°

port via a respective phased line, the second antenna element having an approximately 90°

phase difference with the first antenna element;

a third antenna element coupled to the 180°

port; and

a fourth antenna element coupled to the 180°

port via a respective phased line, the fourth antenna element having an approximately 90°

phase difference with the third antenna element.

8. The antenna of claim 7 wherein the hybrid coupler is a microstrip hybrid coupler.

9. The antenna of claim 7 wherein the hybrid coupler is deposited on a dielectric substrate.

10. The antenna of claim 7 wherein a ground plane is deposited on an opposite side of said dielectric substrate.

11. The antenna of claim 7, wherein the hybrid coupler is a ring hybrid.

12. The antenna of claim 7, wherein the hybrid coupler has no terminated port.

13. The antenna of claim 7, wherein said four radiating elements each have substantially the same length.

14. The antenna of claim 7, wherein said four radiating elements are each coupled to a respective one of said ports at one end, and open circuited at another end.

15. The antenna of claim 7, wherein said four radiating elements are each coupled to a respective one of said antenna ports at one end, and short circuited at the other end.

16. The antenna of claim 7, wherein said four radiating elements are formed into a helix.

17. The antenna of claim 7, wherein said four elements are directly connected to said antenna ports.