Common-Mode Noise Reduction Using Asymmetric Coupled Line With SMD Capacitor

In this paper, a bended differential transmission line using the asymmetric coupled line (ACL) with surface mount device (SMD) capacitor is proposed to suppress the common-mode noise. The bended differential transmission line using the ACL with SMD capacitor can greatly reduce the mode conversion from -6.91 to -13.29 dB and the Time-Domain-Through common-mode noise from 0.063 to 0.023 V as compared with the bended differential transmission line using the right-angle bend. Also, the differential-mode transmission is increased and the small differential-mode reflection is maintained. To verify the simulation results, measurement is done in the frequency and time domains where the measurement results are in good agreement with the simulation results.