The EMC Design Of Bus In Vehicular Communication System

With the development of vehicular communication and bus technology, because there are a lot of devices inside and the amount of bus become more and more, the interference between them is worse and worse , problem of Electromagnetic Compatibility(EMC) in vehicular communication system is serious. Firstly, transmission characteristic of data buses is discussed in the paper, and physical,electric characteristic is researched. Moreover, different coupling principle is represented for different data bus.This paper which is based on the theory of multi conductor transmission lines, deduces classic multi conductor transmission lines equation, analyses the physical meaning of per-unit-length inductance capacitance, resistance and conductance matrixes, establishes coupling mode for different data bus, including naked transmission line coupling mode, shield transmission line coupling mode and data bus coupling mode.Base on above theory and analytic mode, this paper uses computer language of VC and C++ to improve the original software and enhance its accuracy of the calculation. Last, the simulation software is used to study the impact to coupling of the layout of the bus and the characteristics of the transmission signal on bus, the conclusion has the significance in practice.