Modelling of computational electromagnetics problems by using discrete trigonometric transforms matrices

Several problems in Computational Electromagnetics (CEM) including discretizations of scatterers and radiators with the Method of Moments, the Boundary Element Method, and the Method of Auxiliary Sources may be modelled efficiently by exploiting certain properties of block matrices associated with Discrete Trigonometric Transforms (DTT´s). To this direction, in this paper we describe the implementation of certain efficient algorithms for the inversion of such block matrices, which are superior in terms of computational complexity compared to standard inversion techniques. Numerical results are presented demonstrating the CPU-time efficiency as well as the accuracy for ill-conditioned matrices, stemming from specific CEM problems.