A SYSTEMATIC-APPROACH TO THE DERIVATION OF CONSTITUTIVE PARAMETERS OFA PERFECTLY MATCHED ABSORBER

In this letter, the constitutive parameters of a perfectly matched abs orber are derived by imposing the condition that the fields decay with in the absorber in a required manner, and it is shown that this absorb er can be realized as a bianisotropic medium. This strategy is similar to that employed for the realization of perfectly matched layers (PML 's), via the use of anisotropic media, and the imposition of certain c onditions on the complex permittivity and permeability tensors. Howeve r, unlike the PML, the bianisotropic media are desirable candidates fo r physically realizable and passive absorbers. Furthermore, theoretica lly such media have the potential of absorbing incident waves or arbit rary frequency and direction of propagation with no reflection.