A HYBRID FINITE-ELEMENT METHOD FOR NEAR BODIES OF REVOLUTION

A generic formulation for a hybrid finite element solution for three-dimensional electromagnetic scattering is given using the equivalent current approach. The major computational tasks involved in monostatic scattering calculations are analyzed and compared as a function of the method of implementing the near field radiation condition, i.e. Method of Moments (MOM), modal expansion (Mie series), body of revolution (BOR). A new method utilizing a BOR formulation is given which addresses these computational issues. This BOR implementation utilizes Hermite cubic basis functions and a variable number of modes per basis function in order to achieve the greatest efficiency. The combined field integral equation formulation is employed to eliminate non-physical resonances of the mesh boundary. Examples are given showing the efficiency and accuracy of this BOR code by itself, and as part of this new hybrid finite element method.