| 摘要 |
PROBLEM TO BE SOLVED: To enhance a degree of freedom of impedance adjustment and the productivity of assembling mounting components on the printed circuit board. SOLUTION: The printed circuit board 21 on which a drop-in isolator 3 is mounted and having strip lines 5, 6 extended at both sides of the drop-in isolator 3 is formed by a multi-layer board consisting of three layers of front, medium and rear layers; a front layer 22 and a rear layer 23 which respectively correspond to a mount side of the drop-in isolator 3 and the counter-mount side, and a medium layer 24 as a common ground layer of the strip lines on both the front and rear layers 22, 23 and having throughholes 25 for the connection to the strip lines 5, 6, and a metallic piece 27 for impedance adjustment that is connected to the throughhole 25 is formed on the rear layer 23 of the multi-layer board. |
