Electromagnetic Field Modeling And Simulation Of High-speed Backplane

The industry and market needs to promote the performance of electronic systems. As the semiconductor technology advances, the on-chip clock speed and board-level clock speed increases yearly. High-speed circuit bandwidth has accessed to the traditional circuit microwave frequency bands. In order to study the wide bandwidth circuit, using electromagnetic field theory and tools as a major way to analyze signal integrity is inevitable. At this time, in addition to reflection and crosstalk in these low speed occasions, skin effect and dielectric loss the effects as the time scale of signal reduces to sub-nanosecond play a role in the circuit performance. For example, inter-symbol interference is a problem that must be solved.Backplane is board-level interconnect composed of passive devices. Almost no electronic system will leave the backplane or backplane-based structure. Study of high-speed serial backplane is an area developing rapidly in recent years. The industry is also continuing to set new requirements of backplane performance. Backplane study represents a major trend of the high-speed circuit design. Electronic magnetic field numerical method used in high-frequency circuit simulation, design of interconnection and electromagnetic compatibility analysis has been rapidly developed in recent years. Aiming at the broadband analysis and complex structure simulation, finite difference time domain method has obvious advantages. This thesis analyzes the physical mechanism which play a dominant role as the data rate of in PCB becomes Gbps and above. This thesis also uses finite difference time domain method to extract high-speed circuit transmission parameters and rational fit method to model them and to discuss the way to simulate high-speed serial backplane transmission characteristics.The first chapter describes the status and trends of high-speed interconnection, the physical mechanism which play a dominant role as the data rate of in PCB becomes Gbps and above, characteristics of performance region and signal integrity requirements. The first chapter also summarizes common development in the high-speed circuit of the modeling and analysis in recent years. This chapter describes suitable occasion of each kind of model. This chapter points that along with the data rate rising, maximum performance that the system can achieve is often be limited to interconnect materials selection and optimization of interconnect structures and the only way to resolve these problems is using electromagnetic theory and analysis methods.The second chapter describes the electromagnetic FDTD method and its high-speed circuit simulation application. This chapter introduces the FDTD-SPICE simulation method and the equivalent parameter extraction method.Chapter III is an emphasis of this thesis, using finite-difference time-domain to analyze high-speed backplane design, the dielectric loss, and Skin effect on the characteristics of the transmission line and extract the S parameters of discontinues structure in PCB. This chapter also analyzes the decrease of signal integrity of via and split slot in different frequency bands, and use 2D FDTD-SPICE method to calculate the board level power distribution system performance. In the end of this chapter validate the estimation of the common-mode electronic magnetic radiation of the differential line pairs.Chapter IV discusses rational function fitting method of the models in high-speed circuit and presents the examples such via and power distribution system's rational fitting model and HSPICE simulation results.Chapter V attempts to discuss high-speed serial backplane modeling and simulation methods. It introduces modeling method of each unit of differential transmission channel in a high-speed serial backplane and means of the channel parameters, and focuses on analysis of jitter due to crosstalk in differential pairs.Chapter VI summarizes the main ideas this thesis, which is analyzing the major physical mechanism, 3D finite-difference time-domain calculation, parameter extraction, modeling and model simplification and simulation and verification the results. This chapter also pointed out the future work is to verify models and simulation results by test.