This report describes a technique for the creation of MicroSim PSpice® lossy transmission line models of PCB traces using the results of finite element analysis of PCB cross sectional geometry. Ansoft Extractor® analysis software is used to obtain values of capacitance, inductance, resistance and conductance per unit length, which are then used as parameters in the PSpice® models described here.rnThe capacitance, inductance, resistance and conductance values are obtained from the finite element steady state solver, which gives results at a specific frequency, whilst characteristic impedance values are obtained from the static solverrnThe mathematics involved are reviewed showing the application of the circuit parameters to the primitive PSpice® model TRN and the relationship between these parameters and the attenuation factor.rnThe model described is tested by both small signal AC, and transient simulation. The small signal AC results are compared with the attenuation frequency response calculated directly from the finite element characteristic impedance results.
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