Switching noise-induced voltage fluctuation might result in a serious timing skew or false triggering in a high-speed digital system. We propose a new approach called external coupled resistive termination (ECRT) for suppressing this noise. Analyzing the resonant field patterns reveals that the bulk noise is accumulated close to the plane edges because of the open-end boundary condition. Thus, adding extra loading at the field bulk effectively reduces the quality factors and consequently minimizes the noise accumulation. A Y-shaped power distribution network was studied with a frequency controllable input-output (I/O) buffer model. Simulation results indicate that the noise level is significantly suppressed. The optimal noise reduction rate is 80% at resonance with an overall reduction rate of 50%. Scattered placement of the ECRT was also investigated and the corresponding noise reduction rate was 50%. Reasons for that will be discussed.