Patent ID: 7558706

Claim:
A computer-aided simulation method for determining an electromagnetic field of a body to be produced, comprising the steps of: for a body to be produced that contains a plurality of charges and currents, defining a plurality of subregions of the body; in a computer, iteratively performing in each of the plurality of subregions, a global multipole expansion, which represents an effect of charges and currents for distant points in a respective subregion of the plurality of subregions in the multipole expansion, and a local multipole expansion, which represents an effect of charges and currents at points inside the respective subregions of the plurality of subregions in a multipole expansion, until an error measure is of a predetermined size, in a last interaction, by defining a vector I representing a current distribution in the body and initially setting I=0 and changing I in steps in successive iterations, each iteration comprising; a) calculating the global multipole expansion with global multipole coefficients according to c g =GI, c g being a vector composed of the global multipole coefficients of the plurality of subregions, G being a matrix determining the global multipole coefficients in a respective subregion of the plurality of subregions for the given current distribution I; b) calculating the local multipole expansion with local multipole coefficients according to c g =Tc g , c g being a vector composed of the local multipole coefficients of the plurality of subregions, T being a translation matrix through which the global multipoles are combined into local multipoles; c) determining the electromagnetic field from ZI=Z′I+Lc 1 , Z denoting an impedance matrix, Z′ denoting a part of the impedance matrix Z, representing coupling between the subregions, Z′ comprising an impedance of an element that is a component of the subregion of the body, L denoting a matrix for evaluating the local multipole coefficients; determining the electromagnetic field of the body by superposition using the global multipole expansion and the local multipole expansion of the plurality of subregions from the last iteration; using the determined electromagnetic field of the body to assess electromagnetic compatibility of the body with an environment of the body; and if said electromagnetic compatibility is satisfactory, producing the body according to all values in said last iteration.