| 摘要 |
PROBLEM TO BE SOLVED: To avoid impedance of main and sub lines from being decreased, even in the case of miniaturization of the coupler by forming a board made of an electric insulation material, placing the main line on one side of the board, providing an insulation film at least between the main line and the sub line and coupling the sub line to the main line electromagnetically via the insulation film. SOLUTION: A 1st insulation film 41 and a 2nd insulation film 42 are placed between a main line 2 and a sub line 3, and a signal through the main line 2 is coupled to the sub line 3 via the 1st insulation film 41 and the 2nd insulation film 42. A GND electrode 9 is provided in a board 1 and the GND electrode 9 is placed on either of the main line 2 or the sub line 3. Thus, a sufficient distance between the GND electrode 9 and the sub line 3 or the main line 2 is ensured adequately, and then the line impedance is not decreased even when the directional coupler is designed for miniaturization. |
