Amplitude modulation effect of DC-DC converter noise on CMOS logic signal transmission in microstrip PCB

This paper describes an interaction between a dc-dc converter noise and high frequency CMOS logic signal transmission in microstrip PCB. The frequency spectrum of the CMOS logic signal voltage was investigated experimentally. From the result, we made it clear that the switching power supply noise was modulated by the CMOS logic signal, and its sideband noise near the logic signal spectrum transmitted though the CMOS logic signal transmission line.