Left-handed Materials In The Pcb Board Electromagnetic Interference (emi) Reduction Applications

Power bus noise problem and electromagnetic interference(EMI) caused by resonant impedance have became a major concern for engineers engaged in printed circuit board(PCB) design.Electromagnetic Band-Gap(EBG) is an array structure periodically arranged by the dielectric,metal or hybrid of them.The use of proper EBG structure can reduce not only the magnitude of the transfer impedances but also the number of the resonance peaks,thus contribute to the EMI reduction of the power bus.Left-handed(LH) materials are substances with simultaneously negative permittivity and permeability,which make the wave vector,the electric-field vector and the magnetic-field vector in the LH medium form a left-handed system.As a consequence,electromagnetic waves in the LH medium have different behaviors from those in the ordinary right-handed(RH) materials,which have both positive permittivity and positive permeability.Recently,much attention has been received on the study of LH material in both theory and experiments.LH materials have already possessed high value for application in the area of microwave circuit and antenna. However,there are studies indicated that the LH materials also have potential value for application in the area of EMC based on the special EBG structure.This paper firstly describes the concept of EMC.Then we make a review for the LH materials' research background,features,preparation,recent related research and applications.In the third chapter we make a detailed description of the fast algorithm based on a full cavity-mode resonator model and the segmentation method,and we can combine them to make a fast and accurate estimation for the impedances of the power bus.In the fourth chapter we firstly calcualte and analyse the impendance characteristic of a power bus whose dielectric layer is an EBG structure composed of two different right-handed materials.Then we build a new EBG structure by introduce the LH material.The numerical results show that this structure has a better performance than the traditional one and can make a significant contribution to the EMI reduction. Finally,the last chapter of this paper gives a research summary and provides a prospect of the further work.