Research On Fast Calculation Method Of Electromagnetic Radiation Of Spatial Arbitrarily Bending Cable

As the main medium of connecting the electronic equipment,the cable will produce a lot of radiation,which causes the failure of some electronic equipment to pass the radiation test.At present,the research on analytical calculation method of electromagnetic radiation mainly focuses on the straight cable,but the cable often presents arbitrary bending shape in three-dimensional space due to the complexity of line layout when it is actually laid.At the same time,the numerical method takes a long time to solve this kind of problems.Based on the transmission line theory and electric dipole model,this paper takes the unshielded cable and shielded cable as the research objects in order to solve the electromagnetic radiation calculation problem of this kind of space arbitrary bending cable quickly.The research contents are as follows:(1)Research on the fast calculation method of electromagnetic radiation of the arbitrary bending unshielded cable in space.The bending non-uniform cables are divided into several cascades of uniform sub segments because the unit length parameter of bent cable is non-uniform.Based on the bare wires,the influence of insulation layer on cable distribution parameters is further considered,and the transmission line equation of cables with insulation layer of bending is obtained by using the chain parameter matrix;then the electricity of bending cables is obtained by combining the chain parameter matrix and terminal constraints.Finally,the electric current is decomposed in space,and the electromagnetic radiation of bending cable is obtained by electric dipole model.The correctness and efficiency of this method are verified by CST numerical simulation and experimental test.(2)Research on the fast calculation method of electromagnetic radiation of the arbitrarily curved shielded cable in space.On the basis of the derivation model of the electromagnetic radiation calculation method of the space arbitrary bending cable,the fast calculation method of the electromagnetic radiation of the space arbitrary bending shielded cable is further studied.Firstly,on the basis of the existing Kley transfer impedance model,the transfer impedance expression of the braided shielded cable is calculated and verified.Secondly,the distributed excitation voltage and induced current of the screen is obtained by using the transfer impedance and the core current of the shielded cable calculated by the bending transmission line equation.Finally,the calculation method of electromagnetic radiation generated by the shield current is derived by using the dipole antenna model,and the correctness and efficiency of the calculation method are verified by the commercial software CST.(3)Analysis of the influence factors of the radiation characteristics of bending cable in space.The electromagnetic radiation calculation model is further applied to quickly measure the influence of different parameters on the radiation characteristics of bending cable.Firstly,based on the deduced calculation model of electromagnetic radiation of bending cable in space,the influence of the bending degree,cable length,radius,dielectric constant and thickness of the cable with insulating layer on the electromagnetic radiation of bending cable is analyzed.Secondly,based on the calculation model of electromagnetic radiation of bending shielded cable in space,the influence of the bending degree of shielded cable,cross-section parameters,shielding layer parameters and shielding layer materials on electromagnetic radiation of bending shielding cable is analyzed.