Abstract: A directional coupler includes a conductor pattern formed on a substrate. The conductor pattern includes first to fourth lines radially extending from a predetermined point on the substrate, and conductive pattern portions. Each line has a first point a first distance from the predetermined point, and a second point a second distance from the predetermined point, wherein the first and second distances have different values. Respective first or second points of adjacent lines are connected by curves, straight lines, or bent lines with obtuse angles, and the crossing angle defined at an intersection of the connecting lines and edges of adjacent lines is obtuse. The conductive pattern portions are defined by the first to fourth lines and the connecting lines. The conductive pattern portions break degeneracy of a plurality of resonant modes.

Abstract: A directional coupler includes a conductor pattern formed on a substrate. The conductor pattern includes first to fourth lines radially extending from a predetermined point on the substrate, and conductive pattern portions. Each line has a first point a first distance from the predetermined point, and a second point a second distance from the predetermined point, wherein the first and second distances have different values. Respective first or second points of adjacent lines are connected by curves, straight lines, or bent lines with obtuse angles, and the crossing angle defined at an intersection of the connecting lines and edges of adjacent lines is obtuse. The conductive pattern portions are defined by the first to fourth lines and the connecting lines. The conductive pattern portions break degeneracy of a plurality of resonant modes.