Matrix theory approach to complex waves (in shielded lossless guides)

Complex waves in shielded lossless inhomogeneous isotropic guides are investigated. A critical appraisal of the existing theory of complex waves is given and a new approach is proposed. A mathematical condition for the existence of complex waves is derived using the properties of a generalized symmetric matrix eigenvalue problem. It is shown that complex waves may exist in slightly perturbed homogeneous guides as a result of the coupling of a pair of degenerate or nearly degenerate modes.<
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