| 摘要 |
PROBLEM TO BE SOLVED: To easily fine-adjust the impedance of a main line by closely placing a 2nd microstrip line whose one end is connected to a common grounding face of a 1st microstrip line in parallel and closely placing n-sets of via-holes forming a line to the 2nd microstrip line in parallel. SOLUTION: A coupling line 4, that is a microstrip line whose both ends are connected to a common ground face of a board, is placed closely in parallel with a stub line 2 that is an another microstrip line to cause an electromagnetic coupling between them. A signal propagated on the stub line 2 stimulates an electromagnetic field onto the coupling line 4. In order to change the length of the stub line 2, since it is sufficient to change the length of a block where both ends of the coupling line 4 are connected to ground, via-holes 6c, 6d, 6e, 6f, 6g, 6h formed in a line are placed closely in parallel with the coupling line 4 and a via-hole at a proper position is selected, and a jumper is set to the coupling line 4. |
