DIRECTIONAL COUPLER AND MICROWAVE HEATING DEVICE EQUIPPED WITH SAME

摘要

A directional coupler according to the invention includes an opening (11) in a wall surface (10a) of a waveguide (10), and a coupling line (13) on an outer side of the waveguide. The opening is configured to not cross a tube axis (L1) of the waveguide in plan view, and to emit a circularly polarized wave. The coupling line includes first and second transmission lines (13a, 13b) and output parts (131, 132) disposed at both ends, the first and second transmission lines (13a, 13b) 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.