A three dimensional finite element eigenanalysis of reverberation chambers

A study of reverberation chambers based on a three dimensional finite element eigenanalysis is elaborated. For this purpose the electric field vector wave equation is transformed into its weak form using the Galerkin procedure and discretized with the aid of tetrahedral edge elements. The resulting system of equations is then formulated into a generalized eigenproblem for a complex frequency (omega). When losses are ignored this eigenproblem is linear but is highly singular resulting to spurious solutions, a characteristic common to all numerical methods when analyzing lossless cavities. Including wall and material losses the singularity is reduced but the eigenproblem becomes nonlinear. Herein, the lossless case is considered first with an attempt to reject spurious solutions. Artificial air losses are then introduced to handle the singularity and the effects of these losses are checked against analytical solutions for a simple cavity. The rigorous non-linear eigenproblem including the realistic conducting walls and materials losses is currently under consideration.