In this paper a Fractional Brownian surface is considered inside the walls of a horn antenna, the idea is to compare the perfect walls radiation pattern to a rough surface case in order to estimate the error du to imperfect surfaces. The Brownian surface model is based on Gaussian function type, the analysis of the electromagnetic scattering is based on the moment method (MoM) using the basis function as wavelets. The obtained results are compared to previously published work, this has shown very good approximation.
