Conical corrugated microwave feed horn

• US 5,486,839 A
• Filed: 07/29/1994
• Issued: 01/23/1996
• Est. Priority Date: 07/29/1994
• Status: Expired due to Term

• Current Assignee: Winegard Company
• Original Assignee: Winegard Company
• Inventors: Denlinger, Edgar J., Rodeffer, Charles E., Fathy, Aly E.
• Primary Examiner(s): Hajec, Donald T.
• Assistant Examiner(s): PHAN, THO GIA
• Application Number:
  US08/282,787
• Time in Patent Office: 543 Days
• Field of Search: 343/786, 343/762, 343/772
• US Class Current: 343/786
• CPC Class Codes: H01Q 13/0208 Corrugated horns waveguide mouth antenna with corrugated flange H01Q13/065; manufacturing details H01Q13/0283

Abstract

A conical corrugated microwave feed horn. A conical flare section is formed at the aperture of the feed horn and a second smooth cylindrical section is formed at the throat of the feed horn. The conical flare section is formed with two regions. The first region is a corrugated conical region formed at the aperture and having a plurality of slots formed parallel to the central axis of the feed horn. Each slot in the plurality of slots has an inner surface closest to the central axis of the feed horn and an outer surface furthest from the central axis. Connecting the corrugated conical region to the cylindrical throat is a smooth conical region. The first slot adjacent the smooth conical region has first and second formed lips on the terminating end thereof. The lips are formed directed inwardly toward each other. The last slot of the plurality of slots at the aperture of the feed horn has the terminating end of the inner surface extending in length beyond the length of the outer surface.

Claims

1. A conical corrugated microwave feed horn comprising in combination:

a conical flare section, said flare section having a smooth conical region and a corrugated conical region, said feed horn having a cylindrical aperture formed on a first open end,

a cylindrical throat formed on a second open end opposing said cylindrical aperture,

a plurality of slots formed parallel to the central axis of said feed horn in said corrugated conical section, each slot of said plurality of slots having an inner surface with an outer end closest to the central axis of said feed horn and an outer surface furthest from the central axis, said plurality of slots having a first slot connected to said smooth conical region,

said smooth conical region connecting said cylindrical throat to said outer end of said first slot of said plurality of slots, said smooth conical region having a first predetermined angle from the central axis of said feed horn through said first slot connection, said smooth conical region providing an impedance match between said corrugated conical region and said cylindrical throat so as to increase the bandwidth of said feed horn,

each slot of said plurality of slots having the outer end of the inner surface formed on a conical shape having a second predetermined angle from the central axis through said first slot connection, said second predetermined angle being greater in value than said first predetermined angle.

2. The feed horn of claim 1 wherein said first predetermined angle is 49.4 degrees.

3. The feed horn of claim 1 wherein said second predetermined angle is 71.5 degrees.

4. A conical corrugated microwave feed horn comprising in combination:

a conical flare section, said flare section having a corrugated conical region, said feed horn having a cylindrical aperture formed on a first end,

a cylindrical throat formed on the end of said feed horn opposing said cylindrical aperture,

a plurality of slots formed parallel to the central axis of said feed horn in said corrugated conical region, each slot of said plurality of slots having an inner surface with an outer end closest to the central axis of said feed horn and an outer surface furthest from the central axis,

the first slot of said plurality of slots located nearest said cylindrical throat,

at least one lip on said first slot providing (1) a narrower beamwidth for said feed horn and (2) an increase in feed horn gain.

5. A conical corrugated microwave feed horn comprising in combination:

a conical flare section, said flare section having a corrugated conical region, said feed horn having a cylindrical aperture formed on a first end,

a cylindrical throat formed on the end of said feed horn opposing said cylindrical aperture,

a plurality of slots formed parallel to the central axis of said feed horn in said corrugated conical region, each slot of said plurality of slots having an inner surface with an outer end closest to the central axis of said feed horn and an outer surface furthest from the central axis,

the first slot of said plurality of slots located nearest said cylindrical throat,

means on said first slot for providing (1) a narrower beamwidth for said feed horn and (2) an increase in feed horn gain, said means on said first slot for providing comprising;

first and second formed lips on the outer ends of said first slot, said first formed lip formed on the outer end of said inner surface of said first slot and directed radially outward from the central axis toward said outer surface of said first slot, said first slot further having said second formed lip on the terminating end of said outer surface and directed radially inward toward the central axis.

6. The feed horn of claim 5 wherein each of said first and second formed lips extends about 1/20th of the center frequency wavelength of said feed horn into said first slot.

7. A conical corrugated microwave feed horn comprising in combination:

a conical flare section, said flare section having a corrugated conical region, said feed horn having a cylindrical aperture formed on a first end,

a cylindrical throat formed on the end of said feed horn opposing said cylindrical aperture,

a plurality of slots formed parallel to the central axis of the feed horn in said corrugated conical region, each slot of said plurality of slots having an inner surface closest to the central axis of said feed horn and an outer surface furthest from the central axis,

the last slot of said plurality of slots located nearest said cylindrical aperture having the length of the said inner surface extending in distance beyond the length of said outer surface for providing a reduction in the sidelobe levels so as to reduce reflection effects and interferences,

each slot of said plurality of slots between said smooth conical region and said last slot having the length of said outer surface extend in distance beyond the length of said inner surface.

8. The feed horn of claim 7 wherein said inner surface of said last slot extends a distance less than one-half the wavelength of the center frequency of said feed horn.

9. The feed horn of claim 7 wherein said outer surface of said last slot extends a distance less than one-quarter the wavelength of the center frequency of said feed horn.

10. A conical corrugated microwave feed horn comprising in combination:

a conical flare section, said flare section having a smooth conical region and a corrugated conical region, said feed horn having a cylindrical aperture formed on a first end,

a cylindrical throat formed on the end of said feed horn opposing said cylindrical aperture,

a plurality of slots formed parallel to the central axis of said feed horn in said corrugated conical region, each slot of said plurality of slots having an inner surface with an outer end closest to the central axis of said feed horn and an outer surface furthest from the central axis,

said smooth conical region connecting said cylindrical throat to said outer end of the first slot of said plurality of slots, said smooth conical region providing a wider bandwidth for said feed horn,

said first slot of said plurality of slots having first and second formed lips on the terminating ends of said first slot, said first formed lip formed on the terminating end of said inner surface of said first slot and directed radially outward from the central axis toward said outer surface of said first slot, said first slot further having said second formed lip on the terminating end of said outer surface and directed radially inward toward the central axis, said first and second lips providing a narrower beamwidth for said feed horn and an increase in feed horn gain,

the last slot of said plurality of slots having the terminating end of said inner surface extend in length beyond the length of said outer surface for providing a reduction in the sidelobe levels so as to reduce reflection effects and interferences, and

each slot of said plurality of slots between said smooth conical region and said last slot having the length of said outer surface extend in distance beyond the length of said inner surface for reducing sidelobe interference.

11. The feed horn of claim 10 wherein said smooth conical region is formed at an angle of 49.4 degrees from the central axis.

12. The feed horn of claim 10 wherein said corrugated region is formed at an angle of 71.5 degrees from the central axis.

13. The feed horn of claim 10 wherein each of said first and second formed lips extends about 1/20th of the center frequency wavelength of said feed horn into said first slot.

14. The feed horn of claim 10 wherein said inner surface of said last slot extends a distance less than one-half the wavelength of the center frequency of said feed horn.

15. The feed horn of claim 10 wherein said outer surface of said last slot extends a distance less than one-quarter the wavelength of the center frequency of said feed horn.

16. A conical corrugated microwave feed horn for use in the frequency range of 12.2 to 12.7 GHz comprising in combination:

a conical flare section, said flare section having a smooth conical region and a corrugated conical region, said feed horn having a cylindrical aperture formed on a first end,

a cylindrical throat formed on the end of the feed horn opposing said cylindrical aperture,

three slots formed parallel to the central axis of said feed horn in said corrugated conical region, each slot of said three slots having an inner surface closest to the central axis of said feed horn and an outer surface furthest from the central axis,

said smooth conical region connecting said cylindrical throat to said first slot of said three slots,

said first slot of said three slots having first and second formed lips formed at the opening of said first slot, said first formed lip directed radially outward from the central axis, said second formed lip directed radially inward toward the central axis,

the third slot of said three slots having the length of said inner surface extend in distance beyond the length of said outer surface,

the second slot between said first and third slots having the length of said outer surface extend in distance beyond the length of the inner surface.