EFFICIENT ANALYSIS OF SCATTERING BY ARBITRARILY-SHAPED THIN OBSTACLESIN RECTANGULAR WAVE-GUIDE

A moment-method based analysis of arbitrarily shaped zero-thickness ob stacles in rectangular waveguide is presented. The method is discussed in two well-known formulations, and for both of them an efficient Gre en's functions representation is introduced. The representation is obt ained by extracting suitable terms representing the asymptotic behavio ur of the TE and TM part of Green's dyad. Two different sets of basis functions are then compared in terms of accuracy of the numerical resu lts obtained: rooftops and bilinear. It is shown that the higher order set of bilinear basis function leads to spurious results, whereas no such effect appears using rooftops. A very good efficiency of the over all algorithm was observed.