Directional coupler and microwave heater provided with the same

Patent metadata

Field	Value
Publication number	US-10135107-B2
Application number	US-201414425242-A
Country	US
Kind code	B2
Filing date	Jan 31, 2014
Priority date	Jan 31, 2013
Publication date	Nov 20, 2018
Grant date	Nov 20, 2018

Abstract

A directional coupler according to the invention includes an opening in a wall surface of a waveguide, and a coupling line on an outer side of the waveguide. The opening is configured to not cross a tube axis of the waveguide in plan view, and to emit a circularly polarized wave. The coupling line includes first and second transmission lines and output parts disposed at both ends, the first and second transmission lines extending across the opening to cross the tube axis in plan view and being opposed to each other across the center of the opening. The first and second transmission lines are interconnected at a position displaced from an area vertically above the opening.

First claim

What is claimed is:

1. A directional coupler comprising:
a waveguide having an opening in a wall surface thereof; and
a coupling line disposed on an outer side of the waveguide,
wherein the opening is configured to not cross a tube axis of the waveguide in plan view, and to emit a circularly polarized wave, the coupling line includes:
a first transmission line,
a second transmission line, and
output parts disposed at both ends of the coupling line, the first transmission line and the second transmission line extending across the opening in plan view and being opposed to each other across a center of the opening, and the first transmission line and the second transmission line are interconnected at a position displaced from an area vertically above the opening.

2. The directional coupler according to claim 1 , further comprising a printed circuit board, wherein the coupling line is on a first face of the printed circuit board, the face being opposed to the opening.

3. The directional coupler according to claim 1 , wherein the opening is defined by two long holes that cross each other so as to define an X shape.

4. The directional coupler according to claim 1 , wherein the coupling line is between a first coupling point located substantially at a center of a coupling area where the opening crosses the first transmission line, and a second coupling point located substantially at a center of a coupling area where the opening crosses the second transmission line, in plan view, and is configured such that a microwave generated at the first coupling point and a microwave generated at the second coupling point correspond to a rotating direction of a circularly polarized wave, and have a same phase at the first coupling point or the second coupling point.

5. The directional coupler according to claim 2 , further comprising a conductive support part that is configured to support the printed circuit board on an outer face of the waveguide and to surround the opening in plan view, and a microwave reflective member, wherein the microwave reflective member is on a second face of the printed circuit board, the second face opposite the first face and not opposed to the opening.

6. The directional coupler according to claim 5 , wherein the support part has through holes through which both ends of the coupling line pass, and the output parts are disposed outside of the support part.

7. The directional coupler according to claim 6 , wherein the output parts are connected to detection circuits or terminal circuits outside of the support part.

8. The directional coupler according to claim 7 , wherein the detection circuits or the terminal circuits are on the printed circuit board.

9. The directional coupler according to claim 1 , wherein the first transmission line and second transmission line extend substantially perpendicular to a tube axis in plan view.

10. The directional coupler according to claim 9 , wherein one end of the first transmission line and one end of the second transmission line are connected to a third transmission line substantially parallel to the tube axis in plan view.

11. A microwave heater comprising the directional coupler according to claim 1 .

Assignees

• Panasonic Ip Man Co Ltd

Inventors

• Yoshino Koji
• Nobue Tomotaka
• Yasui Kenji
• Omori Yoshiharu
• Sadahira Masafumi
• Kubo Masayuki

Classifications

• H05B6/707

  using waveguides · CPC title

• H05B6/705 Primary

  using microwave tuning · CPC title

• H01P5/184

  the guides being strip lines or microstrips · CPC title

• H01P5/107

  Hollow-waveguide/strip-line transitions · CPC title

• H01P5/181 Primary

  the guides being hollow waveguides · CPC title