Research On The Em Modeling And Optimization Of PCB Through Hole Via

In the high-speed circuit design, signal integrity problems will inevitably arise, the design of transmission path in the system is very important. The transmission paths include transmission lines and through hole vias on high-frequency circuit boards. This paper will focus on the following two problems including transmission line effect and the distributed parameter effect of vias. From the line structure definition, transmission line effect can be understood as the distribution of line parameters on the impact of the online signal. And through-hole effect can be understood as multi-dimensional pore structure of layers of different electrical function board from the location of vias.Firstly,detailed analysis of the physical mechanism of the through-hole design impact of various parameters is given on of the signal integrity theory. The cavity model with coaxial line model equivalent method is taken to extract the capacitance parameters of the through-hole and the results are compared with the theoretical calculation. We introduction four vias modeling methods, and use numerical simulation software HFSS and CST Microwave Studio to establish the full-wave analysis model for model validation and comparison, and get a good result.Through electromagnetic simulation of the signal vias and grounded vias, we get the impact of structural parameters on S parameters. All of the impact of each parameter are considered to optimize the design parameters in the actual circuit. Grounded vias are also proposed to add near the signal vias, which reduce the transmission effectively. And we make a simple microstrip line-through hole-microstrip line structure, and get preliminary results using the network analyzer. By comprehensive study of through-hole electromagnetic model, and the simulation and optimization of the magnetic model, we can improve the signal transmission performance and increase the efficiency of circuit design.This paper focuses on the impact of the high speed PCB EMC and SI issues through vias modeling on these three aspects, including theoretical analysis, simulator modeling and PCB board test. Results show that the optimal design parameters and the added ground vias improve the signal integrity.