Surface impedance of elliptical hollow conducting waveguides

Currently the literature describes two approaches to the determination of power loss in the hollow metallic elliptical waveguide. The well known perturbation method employing the intrinsic impedance of the metal has frequently been used, and an ¿-dependent surface impedance in two different forms has recently been proposed by several workers. In this work it is suggested that sufficient evidence exists to indicate that the ¿-dependent formulation is unnecessary.