# US 5,708,401 A · Waveguide coaxial converter including susceptance matching means

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 5,708,401 A
- Document ID: US5708401A
- Status: Granted
- Kind: A
- Application number: 08/560,782
- Filed: 1995-11-21
- Granted: 1998-01-13
- Earliest claimed: 1994-11-21
- Assignees: NEC Corporation
- Inventors: Keiichi Umezu
- Web page: https://patentgrep.com/patent/US5708401A

## CPC

- H01P 5/103: Hollow-waveguide/coaxial-line transitions
- H01P 5/024: {between hollow waveguides}
- H01P: WAVEGUIDES; RESONATORS, LINES, OR OTHER DEVICES OF THE WAVEGUIDE TYPE (operating at optical frequencies G02B)

## Abstract

Disclosed is a waveguide coaxial converter in the form of a rectangular tube, open at an end opposite a closed end, and in which a high-frequency signal propagates along a central axis perpendicular to the open top; at least two means for regulating a capacitive susceptance which are provided along a line having a predetermined angle to the axis line of the waveguide at a predetermined position on a wide face of the waveguide and are respectively disposed at an interval of one eighth of a guide wavelength .lambda.g in the direction along the axis line; and at least two step portions for stepwise narrowing the width between two internal sidewalls of the waveguide, with a distance of one eighth of the guide wavelength along the direction of the axis line separating the steps; and a tapered ridge rising from one wider internal face to a predetermined height as it progresses away from the open end, with a flat portion extending from the height of the taper to the closed end of the waveguide, to which the center conductor of a coaxial line is connected.

## Claims

### Claim 1

A waveguide coaxial converter, comprising:
a waveguide which is a rectangular tube having an open end opposite a closed end, a central axis perpendicular to the open end, a wide pair of opposing internal faces, and a narrow pair of opposing internal sidewalls, and in which a high-frequency signal propagates;
at least two means for regulating a capacitive susceptance arranged along a line having a predetermined angle to said central axis line of said waveguide at a predetermined position on at least one of said pair of wide faces of said waveguide and are respectively disposed at an interval of one eighth of a guide wavelength .lambda.g in the direction along said central axis line; and
at least two, step portions for stepwise narrowing the width between one pair of opposing internal sidewalls of said waveguide, one of said step portions being provided on each of said opposing internal sidewalls respectively, wherein said at least two step portions are separated from each other by a distance of one eighth of said guide wavelength in the direction along said central axis line.

### Claim 2 (depends on 1)

A waveguide coaxial converter, according to claim 1, wherein:
said waveguide is provided with an internal ridge portion which includes a tapered face gradually rising from one of said wide internal faces as it approaches said closed end of said waveguide and a flat face extending from said tapered face to said closed end, said flat face of said ridge portion being connected with a center conductor of a coaxial line.

### Claim 3 (depends on 2)

A waveguide coaxial converter, according to claim 2, wherein:
said ridge portion has a shape by which an increase of a cut-off frequency caused by said step portions is suppressed.

### Claim 4 (depends on 1)

A waveguide coaxial converter, according to claim 1 in which at least one of said step portions is longitudinally aligned with one of said means for regulating capacitive susceptance.