Eigenvalues and eigenfunctions of plane waveguide with differ walls impedances

The analytical solution of excitation of the plane waveguide with perfectly conductive walls which coincide with the coordinate plane is well-known. In the case of lossy walls the problem can be reduced to transcendental equation which can be solved numerically. A numerical method and the results of eigenvalues derivation for the case of arbitrary non-zero walls' impedances are presented. The method presented guaranties roots isolation.