Research On Regulation Of Dielectric EBG For EMI Suppression In Power Distribution Networks

With the unceasing improvement of the integration and operating frequency of high-speed multilayer printed circuit boards(PCBs),the internal electromagnetic interference(EMI)becomes more and more serious.Among which,the synchronous switching noise(SSN)in the power distribution network(PDN)is a prominent problem.Traditional electromagnetic noise suppression methods have problems such as limited operating frequency,large occupied space,thermal issue and so on,which making it difficult to meet application requirements.Dielectric electromagnetic band-gap(EBG)structure has received extensive attention due to their advantages like wide band gap,high frequency,compact structure,flexible regulation and good signal integrity.In consideration of the intensive requirements of the electromagnetic noise suppression technology with miniaturized,wide-band,and high isolation characteristics for the communication divices working in the sub-6 and millimeter-wave working frequency range,the noise isolation performance and the regulation of the dielectric EBG stucture are intensively studied in the thesis.The research contents are as follows:(1)The algorithms of finite-element method for calculating the noise isolation performance of dielectric EBG are studied.A one-dimensional finite-element method and a two-dimensional finite element method are provided for both of the one-dimensional EBG and two-dimensional EBG,which use the method of directly solving the wave equation.The proposed FEM method can obtain the noise isolation and the frequency band gap simultaneously,which is especially suitable for the EBG structure with few periods.(2)The influences of the dielectric constant,period numbers and period length of EBG units on the performance of band gap as well as its regulation are investigated.One-dimensional and two-dimensional dielectrics EBG are analyzed in the frequency range of100 MHz～10 GHz and 20～30 GHz,.(3)The effects of EBG cell shape and arrangement on the band gap and noise isolation performance are analyzed.(4)The smallest size of EBG structures in the frequency range of 100MHz～10GHz and20～30GHz are analyzed.(5)The influence of dielectric EBG on the transmission performance of via in power distribution network is analyzed.The results of research show that the proposed one-dimensional finite-element method and two-dimensional finite-element method are concision,which can significantly reduce the needed computer memory and the calculation time.The simulation results verify the rationality of the method.With the parameter adjustment,one-dimensional EBG and two-dimensional EBG can achieve good band gap characteristics on the frequency below 6 GHz and the millimeter wave frequency band of 20-30 GHz,but it is difficult to obtain band gap below 3GHz.Through the proper regulation,the minimum size of one-dimensional and two-dimensional EBGs can reach 5 mm～10 mm.The reflection of EBG will not reduce the transmission quality of via signal,on the contrary,this structure can enhance the signal integrity on the contrary.Compared with the one-dimensional dielectric EBG,the advantage of the two-dimensional dielectric EBG is that whose band gap can be obtained in the two-dimensional direction,however,when the dielectric constant is lower,the band gap and noise isolation performance of the two-dimensional dielectric EBG are more worse than that of the one-dimensional dielectric EBG.The theoretical analysis is preliminarily verified by the experimental measurment.