Power based considerations on the spectral domain analysis of leaky waves in covered strip-like transmission lines

The paper analyses the power flux characteristics of the different representations of the electromagnetic field of leaky modes in covered lossless strip-like structures in terms of nonuniform modes of the background parallel plate waveguide. Spectral domain analysis is used to compute the propagation characteristics of leaky wave solutions. The relation between the choice of the inversion contour for the spectral Green dyad and the field expansion in background waveguide modes is also investigated and the radiated power flux associated with each expansion (or inversion contour choice) is shown. Finally, we discuss the conditions of excitation for the different leaky wave solutions that can be obtained following different Green dyad inversion contours