Patent ID: 7388449

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; signal ground wiring one end of which is connected to said differential driver, and is wired outside of said differential transmission line along said differential transmission line; a coil unit in which each of said plus line signal wiring, said minus line signal wiring, and said signal ground wiring is wound in a same winding direction; a first impedance element and a second impedance element which have substantially the same impedance value, and which are arranged at a position closer to the output side of said coil unit, than said differential receiver, and which are connected in series, and which are connected in series between said plus line signal wiring and said minus line signal wiring; and a third impedance element which is arranged at a position closer to the output side of said coil unit, than said differential receiver, and which are connected in series, and one end of which is connected to a junction point, where said first impedance element and said second impedance element are connected mutually, and another end of which is connected to another end of said signal ground wiring.