DIRECTIONAL COUPLER HAVING REDUCED-LENGTH AND IMPROVED-DIRECTIVITY BY UNBALANCED COUPLED-TRANSMISSION-LINE STRUCTURE

摘要

PURPOSE: A directional coupler is provided to improve a performance of coupler by designing a structure of a main transport line and a coupling line in mutual unbalance. CONSTITUTION: An input port(103) inputs an incident electromagnetic wave. A main transport line(104) transports the incident electromagnetic wave. An output port(105) outputs a pass power which passes through the main transport line(104). A coupling line(108) divides a power corresponding to the incident electromagnetic wave. A coupling port(107) outputs a coupling power. A combination region of the coupling line(108) with the main transport line(104) is less than lambda/4 about an operation frequency band. A diameter of the coupling line(108) and the main transport line(104) are designed in mutual unbalance.