Directional coupler, high frequency circuit module and wireless communication system

摘要

A directional coupler for detecting an output of a high frequency circuit module includes a main line and a sub-line overlapped with the main line each other with a dielectric material. The sub-line is set, in the width, narrower than the main line and both side edges of the sub-line are allocated at the internal side of both side edges of the main line. Accordingly, the sub-line is surely provided opposed to the main line in the total width area and a signal current flowing into the main line can be detected in higher accuracy. Therefore, a wireless communication system for controlling an output of the high frequency circuit module by comprising such directional coupler assures stable communication.