Mushroom-Type Ground Plane Structure for Wideband SSN Suppression in High-Speed Circuits

A novel design of ground plane with mushroom-type structures is proposed for wideband suppression of simultaneous switching noise (SSN) in high-speed printed circuit boards. The mushroom-type ground plane (MGP) structure consists of two square patches which are connected to the ground plane by specially designed traces and vias. It is more compact than the mushroom-type electromagnetic bandgap (MEBG) structure where the whole middle layer is occupied by periodic patches. Simulation and measurement results show that the SSN is suppressed significantly by the MGP. A -30 dB suppression bandwidth extending from 600 MHz to 7.5 GHz is achieved by a modified MGP structure.