Signal Integrity Analysis And Optimization Of High-speed PCB Transmission Path

With the miniaturization of electronic equipment and the rapid increase in the frequency of 5G signals in circuits,the transmission rate and clock frequency of electronic control systems are constantly rising and increasing.The current clock frequency rises from the original tens of MHz to several GHz,the signal conversion time changes from nanoseconds to picoseconds,the clock and bus frequencies rise rapidly,and the signal rising edge becomes extremely steep,resulting in signal transmission on the PCB.The path has a great problem on the performance of the electronic control system.The design of the transmission path plays a key role in the signal integrity on the PCB.The via and the transmission line are two key devices for signal integrity conduction.Therefore,The calculation and analysis of vias and transmission lines can help solve the problem of signal integrity in high-speed PCB circuit.This article first determines the importance of the signal integrity problem,makes an important discussion of the signal integrity problem,and gives a variety of numerical modeling methods.The physical and electrical meanings of vias and transmission lines are expounded.The classification of via models and transmission line models is discussed,and the theoretical analysis of via structure and transmission line model structure is made.An area decomposition finite element subtraction method is proposed to theoretically calculate and analyze vias and transmission lines,and this method is elaborated in detail.By adopting Ansys HFSS,a simulation structure model of vias and transmission lines is established,and the influence of various parameters on transmission lines and vias is discussed.Finally,according to the physical model of vias and transmission lines,the corresponding real PCB board is established,and the vector network analyzer is used to test the PCB board,and the simulation results are compared to ensure the accuracy of the simulation model.This paper simulates the electromagnetic characteristics of transmission lines and vias,analyzes the effects of structural parameters of vias and transmission lines on signal transmission performance,and obtains the following conclusions:(1)When the differential line spacing is twice the width of the differential line,the characteristic impedance of the differential line performs better;(2)Simulation and experiments show that the semi-circular arc structure can effectively reduce the corner radiation of the transmission line by 11.2% compared with the traditional corner structure;(3)Optimize the parameters of the radius of the via,the pad size,and the spacing of the holes to obtain that the performance of the through hole is better than that of the buried hole and the pad has little effect on the via.Increase the spacing between the two holes appropriately Can reduce the crosstalk between the two holes.