CALCULATION OF THE NATURAL FREQUENCIES OF COMPLEX OBJECTS USING A FINITE-ELEMENT NEAR-FIELD COMPUTATION METHOD

The problem of determining the complex natural frequencies of dosed ob jects with arbitrary shape is considered. The surface of the complex b ody, which is supposed to have an infinite conductivity, is divided in to a large number of plane patches (finite elements) where the current is assumed to be constant. The appropriate boundary condition for the electric field on the surface of the complex body is imposed, yieldin g a homogeneous system of equations for the current coefficients. The regions of resonance (natural frequencies) of the complex object are d etermined as those where the determinant of this system is close to ze ro. As an example, the complex natural frequencies of a rectangular pa rallelpiped (or a cube) are calculated.