Analyse Of Signal Integrity In High Speed Interconnection System

In the high-speed interconnection systems, signal integrity problems can be created through the interconnectk, such as high-speed signal delay, reflection, crosstal, attenuation and dispersion. How to fully consider Signal Intergrity and take effective measures has been one of the pop task in PCB design flow. In this paper, the main research content is based on the theory of electromagnetic field was carried out on the signal integrity problems encountered in the actual project theoretical analysis, and combining with the engineering experience gives the general conclusion, aims to provide a reference for the design of signal integrity engineer.First of all, the mismatch between signal ports often leads to weak signal integrity in engineering applications, to solve this problem, this article takes two-port network as an example, the relation between the port normalized impedance and S parameters has been quantified, moreover, the experiences of engineering has been summed up, and the general port calibration method of high-speed differential interconnect has been given.Secondly, in view of how the common-mode current is generated in high-speed system design, take the symmetrically differential transmission lines and asymmetric differential transmission line as the research object, the partial element equivalent circuit(PEEC) algorithm has been used to extracted the equivalent circuit of two transmission lines, and by using the CST, the field and road simulation of these two transmission lines has been executed separately, and the results from field simulation and road simulation has been compared to prove the accuracy of the algorithm, through the analysis of the current distribution of two differential transmission line, gives the following conclusions: the common-mode current generated from asymmetrical reference plane, radiation of common mode current is the main source of EMI in high-speed interconnect.At last, S parameter, TDR, eye diagram and EMI simulation program of the complete set of high speed connector has been given, aiming to help the signal integrity engineers with the preliminary design of high-speed system, and the elimination of the potential signal integrity problems.