| 摘要 |
PROBLEM TO BE SOLVED: To prevent waveform distortion of a transmission signal by suppressing reflection of the signal at through-holes in the mounting printed circuit board with the through-holes to which signal lines are connected. SOLUTION: Ground through-holes 21 are provided in the vicinity of a through-hole 14 connecting to microstrip lines 13 placed on a front side of the printed circuit board, and a diameterϕof the through-hole 21 or a distance L from the through-hole 14 is selected properly. Thus, the impedance of the through-hole 14 is in matching with the impedance of the microstrip line 13, so as to suppress effectively the reflection of signal at a connecting point between the microstrip line 13 and the through-hole 14. |
