Patent ID: 7397322

Claim:
A radiation noise suppression circuit for a differential transmission line, comprising: a differential transmission line which has plus line signal wiring to which a plus line signal of a differential signal is applied, and minus line signal wiring to which a minus line signal of said differential signal is applied, and connects a differential driver and a differential receiver; plus line signal ground wiring and minus line signal ground wiring which are connected between said differential driver and said differential receiver, and are wired along said differential transmission line; and a coil unit in which each of said plus line signal wiring, said minus line signal wiring, said plus line signal ground wiring, and said minus line signal ground wiring is wound in a common winding direction, wherein a distance between said plus line signal wiring and said plus line signal ground wiring is substantially equal to a distance between said minus line signal wiring and said minus line signal ground wiring, said plus line signal wiring and said minus line signal wiring are arranged so as to be sandwiched between said plus line signal ground wiring and said minus line signal ground wiring, and a distance between said plus line signal wiring and said minus line signal wiring is shorter than a distance between said plus line signal wiring and said plus line signal around wiring.