| 摘要 |
PROBLEM TO BE SOLVED: To realize a micro strip line transmission circuit which can match the impedance of a pad part wiring to that of a signal line. SOLUTION: A metallic case 2 forming a part of the ground face is provided with a recessed part 3, and the space between a pad part 14 for mounting of chip parts and the ground face is widened by h2 to reduce the electrostatic capacity between this pad part 14 and the ground face. That is, the electrostatic capacity is reduced by the extent by which the electrostatic capacity is increased by making the width of the pad part 14 wider than that of a micro strip line 12. Thus, the impedance between the pad part 14 and the ground face is matched to that between the micro strip line 12 and a pattern 1 for ground potential. |
