Research On Cable Crosstalk Coupling Model Method

As the development of electronic information technology, interconnect space between the system and equipment is getting smaller and smaller, and the amount of interconnect structure is becoming more and more complex, interconnect cable is on the increase. In order to ensure the normal operation of electrical and electronic equipment and systems, studying the coupling characteristics of cable has become an important direction of EMC problems. Calculation and simulation of cable coupling is one of the main aspects of prediction of EMC test technology, and it also has practical application value.In this paper, the method of frequency characteristic of cable crosstalk coupling model is studied, and the following procedures are shown to solve the coupling model:extracting the per-unit-length parameters, establishing model equation, solving equation, expanding the model, simplifying the complex model. It studies that the frequency crosstalk coupling of lossless multi-conductor transmission line, shielding wire and multi-conductor transmission line network with transmission line theory, BLT equation and cables equivalent simplified method.Calculating the per-unit-length parameters of multi-conductor transmission line is the base of establishing the crosstalk model.The problem of convergence and symmetry of per-unit-length capacitance matrix calculated based on numerical method (moment method) are respectively further studied for three kinds of typical cable structure. And the principle of the match-point selection and the best match-point allocation scheme are shown in the conclusion.Based on the per-unit-length parameters and multi-conductor transmission line equation, the modulus of decoupling method and chain parameters method are given according to different terminal conditions. The equation of coupling on single line to shielding wire is derived and coupling model is established. By using the multi-conductor transmission line theory, the admittance equation of multi-conductor transmission line networks is further derived based on the concept of pipeline and node. The correctness of the models is verified by the simulation and experiments.Frequency BLT equation of multi-conductor transmission line and shielding wire are derived, super cable network BLT matrix equation is further studied, and the construction method of scattering matrix is improved. The super matrix equation is applied to typical cable network including tree network, star network and loop network.Finally, on the basis of simplified method of bare wire cables bundles, the steps of equivalent simplified method is adjusted to build the crosstalk coupling model of dielectric-coated cable bundles. The equivalent simplified method of cable bundles network is further studied and simplified model is established. The simplified procedure is also shown. The MTL theory and BLT equation are used to verify the correctness of the model. The results show that the simplified method can greatly reduce the computation time and memory with meeting to certain precision.