Feed-horn with helical antenna element and converter including the same

• US 5,699,072 A
• Filed: 05/28/1996
• Issued: 12/16/1997
• Est. Priority Date: 05/29/1995
• Status: Expired due to Term

• Current Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Inventors: Yoshimura, Yoshikazu, Tokuda, Katsuhiko
• Primary Examiner(s): Wimer, Michael C.
• Application Number:
  US08/654,458
• Time in Patent Office: 567 Days
• Field of Search: 343/895, 343/789, 343/786, 343/872
• US Class Current: 343/786
• CPC Class Codes: H01Q 1/247 with frequency mixer, e.g. for direct satellite reception or Doppler radar
• CPC Class Codes: H01Q 11/08 Helical antennas
• CPC Class Codes: H01Q 13/02 Waveguide horns

Abstract

The feed-horn with helical antenna element of this invention comprises (1) a waveguide made of conductive cylinder having a step inside, the inner diameter in the vicinity of the opening face of the waveguide is larger than that of the base of the waveguide, and (2) a helical antenna element disposed at the base axial center of the waveguide. Introduction of the step-formed inside to the waveguide makes it possible to obtain excellent characteristics both of cross polarization and impedance.

Claims

1. A feed-horn with a helical antenna element comprising:

a waveguide comprising a cylindrical conductor having a step inside, wherein a diameter in the vicinity of an opening face of said waveguide is larger than a diameter in the vicinity of a base of said waveguide,

a helical antenna element disposed at the center of said base, and

a cap closing said opening face, said cap being made of a dielectric material and having a concaved face of which the top is protruded toward said base and is located under said opening face.

2. The feed-horn with a helical antenna element of claim 1, wherein said concaved face is a multi-level concaved face having different curvatures.

3. The feed-horn with a helical antenna element of claim 1 including a groove disposed on said cylindrical conductor along outer circumference of said opening face.

4. The feed-horn with a helical antenna element of claim 3, wherein said groove has a cross sectional shape where groove width tapers toward a depth direction.

5. A converter comprising:

a feed-horn with a helical antenna element comprising a waveguide comprising a cylindrical conductor having a step inside, wherein a diameter in the vicinity of an opening face of said waveguide is larger than a diameter in the vicinity of a base of said waveguide, a helical antenna element disposed at the center of said base, and a cap closing said opening face, said cap being made of a dielectric material and having a concaved face of which the top is protruded toward said base and is located under said opening face, and

a micro-strip line electrically connected to a straight-line segment of said helical antenna element.

6. The converter of claim 5, wherein said concaved face is a multi-level concaved face having different curvatures.

7. The converter of claim 5 including a groove disposed on said cylindrical conductor along outer circumference of said opening face.

8. The converter of claim 7, wherein said groove has a cross sectional shape where groove width tapers toward a depth direction.