Performance of an anisotropic artificial absorber for truncating finite-element meshes

A new artificial material absorber for truncating finite element meshes is investigated. The interface of the absorber is made reflectionless by choosing /spl epsiv//sub r/ and /spl mu//sub 4/ to be complex diagonal tensors. With some loss, a metal backed thin absorber layer is then sufficient for terminating the mesh. This scheme is simpler to implement than conventional absorbing boundary conditions and offers the potential for higher accuracy. We investigate the effectiveness of this anisotropic absorber on the basis of results obtained for problems in propagation (waveguide and microstrip line) and scattering.