Patent ID: 9653771
Date: 2017-05-16
CPC Classifications: H01P,H03H

Claim:
1. A directional coupler comprising: an input port; an output port; a coupling port; a terminal port; a main line connecting the input port and the output port; a first subline section, a second subline section and a third subline section each of which is formed of a line configured to be electromagnetically coupled to the main line; a first matching section; and a second matching section, wherein the first to third subline sections and the first and second matching sections each have a first end and a second end opposite to each other, the first end of the first subline section is connected to the coupling port, the first end of the first matching section is connected to the second end of the first subline section, the first end of the second subline section is connected to the second end of the first matching section, the first end of the second matching section is connected to the second end of the second subline section, the first end of the third subline section is connected to the second end of the second matching section, the second end of the third subline section is connected to the terminal port, and the first matching section and the second matching section are configured to cause changes in phase of high frequency signals passing therethrough, and have mutually different characteristics so as to create two attenuation poles in a frequency response of a coupling of the directional coupler.