Ortho-mode transducer with wide bandwidth branch port

• US 8,994,474 B2
• Filed: 04/23/2012
• Issued: 03/31/2015
• Est. Priority Date: 04/23/2012
• Status: Active Grant

• Current Assignee: Optim Microwave Inc.
• Original Assignee: Optim Microwave Inc.
• Inventors: Mahon, John P., Espino, Cynthia P.
• Primary Examiner(s): Jones, Stephen E
• Assistant Examiner(s): OUTTEN, SAMUEL S
• Application Number:
  US13/453,913
• Publication Number:
  US 20130278352A1
• Time in Patent Office: 1,072 Days
• Field of Search: 333/137
• US Class Current: 333/137
• CPC Class Codes: H01P 1/161 sustaining two independent orthogonal modes, e.g. orthomode transducer combining or separating polarisations and frequencies H01P1/2131
• CPC Class Codes: H01P 1/213 combining or separating two or more different frequencies H01P1/215 takes precedence

Abstract

An ortho-mode transducer may include a cylindrical common waveguide terminating in a common port, a rectangular vertical branch waveguide in-line with the cylindrical common waveguide and terminating in a vertical port, and a rectangular horizontal branch waveguide normal to the common waveguide and terminating in a horizontal port. The vertical branch waveguide may be configured to couple a first linearly polarized mode from the vertical port to the common waveguide. The horizontal branch waveguide may be configured to couple a second linearly polarized mode, orthogonal to the first linearly polarized mode, from the horizontal port to the common waveguide. A portion of the vertical branch waveguide may overlap a portion of the cylindrical common waveguide. A septum may span the vertical branch waveguide proximate to the overlapping portions of the vertical branch waveguide and the common waveguide. A rectangular symmetry cavity may be opposed to the horizontal branch waveguide.

Claims

1. An ortho-mode transducer comprising:

a cylindrical common waveguide terminating in a common port;

a generally rectangular vertical branch waveguide in-line with the cylindrical common waveguide, the vertical branch waveguide terminating in a vertical port opposed to the common port, the vertical branch waveguide configured to couple a first linearly polarized mode from the vertical port to the common waveguide, a portion of the vertical branch waveguide overlapping a portion of the cylindrical common waveguide to form a waveguide segment having a cross-section that is a composite of a circular cross-section of the common waveguide and a generally rectangular cross-section of the vertical branch waveguide;

a septum spanning a long dimension of the vertical branch waveguide proximate to the overlapping portions of the vertical branch waveguide and the common waveguide;

a generally rectangular horizontal branch waveguide normal to the common waveguide and the vertical branch waveguide, the horizontal branch waveguide terminating in a horizontal port, the horizontal branch waveguide configured to couple a second linearly polarized mode from the horizontal port to the common waveguide, the second linearly polarized mode orthogonal to the first linearly polarized mode; and

a generally rectangular symmetry cavity opposed to the horizontal branch waveguide.

2. The ortho-mode transducer of claim 1, wherein the horizontal branch waveguide comprises:

a first horizontal branch waveguide segment terminating in the horizontal port;

a third horizontal branch waveguide segment coupled to the common waveguide; and

a second horizontal branch waveguide segment coupled between the first horizontal branch waveguide segment and the third horizontal branch waveguide segment.

3. The ortho-mode transducer of claim 2, wherein

a cross-sectional shape of the third horizontal branch waveguide segment is contained within a cross-sectional shape of the second horizontal branch waveguide segment, and

the cross-sectional shape of the second horizontal branch waveguide segment is contained within a cross-sectional shape of the first horizontal branch waveguide segment.

4. The ortho-mode transducer of claim 3, wherein one or more of the first, second, and third horizontal branch waveguide segments is a ridged waveguide.

5. The ortho-mode transducer of claim 2, wherein one or both of the first and second symmetry waveguide segments is a ridged waveguide.

6. The ortho-mode transducer of claim 1, wherein the symmetry cavity comprises:

a first symmetry waveguide segment terminating in a symmetry port;

a second symmetry waveguide segment coupled between the first symmetry waveguide segment and the common waveguide; and

a shorting plate closing the symmetry port.

7. The ortho-mode transducer of claim 6, wherein

a cross-sectional shape of the second symmetry waveguide segment is contained within a cross-sectional shape of the first symmetry waveguide segment.