PPW Noise Mitigation in Multilayer PCBs by Means of Virtual Island And/or Array of Shorting Vias

This paper describes the parallel-plate waveguide (PPW) noise mitigation by means of shorting vias and/or Virtual Island. The proposed method is already know in literature, nevertheless important considerations are here addressed: 1) the same noise mitigation level proposed in [S. Nam et. al., IEEE Trans. on Microwave Theory and Technique (2005)] can be achieved by using only shorting vias, 2) the noise mitigation is strictly related to the number of shorting vias, the position and the distance from the signal via, 3) -60 dB noise suppression is obtained when array of shorting vias is used. The mitigation level is investigated both in time domain and frequency domain. Different configurations are studied and the impact of power plane with etched slots due to Virtual Islands on the signal integrity is also analyzed by evaluating TDR and insertion loss of a single-ended microstripline passing from top to bottom layer by means of a through via.