Finite Element Software For Practical EMIProblems

MAGNA/EMI is a finite element code based on the coupled A 0 method for three-dimensional electromagnetic (EM) field analysis. The paper describes this four-component vector/scalar potential formulation in some detail. It explains how to choose the gauge condition for each application model and how to set the electric and magnetic field directions on the boundary surfaces. The perfectly matched layer (PML) concept is used as the absorbing boundary condition (ABC). The accuracy of results is confirmed by comparison with analytical solutions for the voltage standing wave ratio (VSWR) and skin depth computation. Computed and analytical values agree well even when the finite element aspect ratio is less than optimal. Both incomplete Cholesky conjugate gradient (ICCG) and Gauss-type equation solvers are available with MAGNA/EMI. A comparison of the solvers is made for both geometrical and electrical bad aspect ratio problems. Two practical applications, cellular phone shield-design and electromagnetic resonance inside a car, are presented as examples. They demonstrate that MAGNA/EMI is a valuable tool in the hands of EMI/EMC engineers.