Implementation of surface impedance boundary conditions in the cell method via the vector fitting technique

Purpose To show a possible implementation of surface impedance boundary conditions (SIBCs) in a time domain formulation based on the cell method (CM). Design/methodology/approach The implementation is based on vector fitting (VF), a technique which allows a time domain representation of a rational approximation of the surface impedance to be found. Findings It is shown that very little computational effort is needed to find a very good VF approximation of simple SIBCs and that such approximation is easily fitted into existing CM codes. Research limitations/implications The extension to higher order SIBCs has not been taken into account. Practical implications The proposed approach avoids the use of convolution integrals, is accurate and easy to implement. Originality/value This paper introduces the use of VF for the approximate time domain representation of SIBCs.