| 摘要 |
PROBLEM TO BE SOLVED: To improve a reflection property in a circuit board that is configured by connecting a microstrip line and a strip line via a through-hole.SOLUTION: A circuit board 1 includes: a microstrip line 2 including a first substrate part 10, a first line 11 and a ground 12; a strip line 3 including a second substrate part 20, a second line 21 and grounds 22 and 23; and a through-hole 31 connecting the first line 11 and the second line 21 in such a manner that a high frequency can be transmitted. Between the through-hole 30 and the second line 21, an impedance matching part 7 formed from a conductor foil is provided. The conductor foil forming the impedance matching part 7 has a length corresponding to an odd multiple of λ/4(λ is a wavelength of a high frequency to be transmitted) from the through-hole 30 and is set wider than the second line 21 which is continuous with the conductor foil.SELECTED DRAWING: Figure 1 |
