抄録
This paper shows, by experiment, that the use of PCB made of lossy material can efficiently reduce radiated noise from digital circuit. The lossy materials used in our experiment have a dielectric constant of 13 or so, with a wide variety of loss tangents ranging from 0.016 to 0.04. Results of the experiment show that the radiated emission from the circuit is considerably affected by the kind of lossy materials used. It is also found in the experiment that a larger face-to-face area, which has been defined by the author as the area of the Vcc patterns facing the ground plane, will lead to a larger reduction in the noise.
