Smooth-walled feedhorn

Patent metadata

Field	Value
Publication number	US-9373891-B2
Application number	US-201514820514-A
Country	US
Kind code	B2
Filing date	Aug 6, 2015
Priority date	Oct 9, 2009
Publication date	Jun 21, 2016
Grant date	Jun 21, 2016

Abstract

A device for at least one of receiving and transmitting electromagnetic radiation includes a feedhorn having a substantially smooth, electrically conducting inner surface extending from an open end to a feed end, the inner surface being substantially rotationally symmetrical about a longitudinal axis, wherein an orthogonal distance from a point on the longitudinal axis to the substantially smooth, electrically conducting inner surface increases monotonically as the point on the longitudinal axis is selected at successively greater distances from the feed end of the feedhorn towards the open end of the feedhorn such that a profile of the substantially smooth, electrically conducting inner surface of the feedhorn is monotonically increasing. The feedhorn has an operating bandwidth and the feedhorn provides a maximum of −30 dB cross polarization response over at least 15% of the operating bandwidth. A method of producing a feedhorn for receiving or transmitting electromagnetic radiation includes determining a profile of an inner surface of the feedhorn based on constraints required to achieve a plurality of operating parameters, providing a pre-machined feedhorn having an initial inner surface, and machining the initial inner surface of the pre-machined feedhorn to substantially match the profile determined to achieve the plurality of operating parameters for the feedhorn. The determining the profile includes a constraint for the profile to be a monotonically increasing profile relative to a rotational symmetry axis of the inner surface of the feedhorn going from a narrow end to a wide end of the feedhorn.

First claim

We claim:

1. A method of producing a feedhorn for receiving or transmitting electromagnetic radiation, comprising:
determining a profile of an inner surface of said feedhorn based on constraints required to achieve a plurality of operating parameters;
providing a pre-machined feedhorn having an initial inner surface; and
machining said initial inner surface of said pre-machined feedhorn to substantially match said profile determined to achieve said plurality of operating parameters for said feedhorn,
wherein said determining said profile includes a first constraint for said profile to be a monotonically increasing profile relative to a rotational symmetry axis of said inner surface of said feedhorn going from a narrow end to a wide end of said feedhorn, and
wherein said determining said profile includes a second constraint for an E-plane and an H-plane co-polar response of said feedhorn to be sufficiently equal such that the cross polarization response over all angles is less than a pre-determined value.

2. A method of producing a feedhorn according to claim 1 , wherein said plurality of operating parameters include a cross polarization response and a return loss of said feedhorn.

3. A method of producing a feedhorn according to claim 1 , wherein said feedhorn has an operating bandwidth and provides a maximum of −30 dB cross polarization response over at least 15% of said operating bandwidth.

4. A method of producing a feedhorn according to claim 3 , wherein said maximum of −30 dB cross polarization response is provided over at least 20% of said operating bandwidth.

5. A method of producing a feedhorn according to claim 3 , wherein said maximum of −30 dB cross polarization response is provided over at least 30% of said operating bandwidth.

6. A method of producing a feedhorn according to claim 3 , wherein said operating bandwidth of said feedhorn is in a microwave region of the electromagnetic spectrum.

7. A method of producing a feedhorn according to claim 3 , wherein said operating bandwidth of said feedhorn is from 33 GHz to 45 GHz.

8. A method of producing a feedhorn according to claim 3 , wherein side lobes of response of said feedhorn are less than at least −20 dB below a peak response of said feedhorn.

9. A method of producing a feedhorn according to claim 1 , wherein said feedhorn has a return loss of less than about −25 dB.

10. A feedhorn produced according to the method of claim 1 .

11. A method of producing a feedhorn according to claim 1 , wherein determining a profile of an inner surface of said feedhorn based on constraints further comprises applying said constraints at a plurality of points on said inner surface of said feedhorn, wherein a distance between each one of said plurality of points and an adjacent one of said plurality of points is less than or equal to λ c /2, where λ c is a cutoff wavelength of an input waveguide section of the feedhorn.

Assignees

• Univ Johns Hopkins
• Us Of America As Represented By The Administrator Of The Nat Aeronautics And Space Administration
• Us Of America As Represented By The Administration Of The Nat Aeronautics And Space Administration

Inventors

• Bennett Charles L
• Zeng Lingzhen
• Wollack Edward J
• Chuss David T

Classifications

• Y10T29/49018

  with other electrical component · CPC title

• H01Q13/0283 Primary

  Apparatus or processes specially provided for manufacturing horns · CPC title

• H01Q13/02 Primary

  Waveguide horns · CPC title

• Y10T29/49016

  Antenna or wave energy "plumbing" making · CPC title