Analysis of the effect of shunt traces on the radiation from printed circuit boards

A simple model for the analysis of the effect of shunt traces (or partial striplines, or image planes) on the radiation of a microstrip trace is presented. The analysis is based on a full wave moment method solution combined with a multi-port network formulation. The major simplification introduced is the assumption of an air dielectric substrate. Emission reduction by shunt traces is a strong function of the number and position of the shorting pins used to connect the shunt trace to the ground plane. The present model allows a convenient examination of this effect and helps in developing design guidelines. Indirect comparisons with measured results available in the literature have been carried out to justify the model