Propagation and excitation of electromagnetic modes in ionospheric waveguides

Electromagnetic modes directed by ionospheric waveguides are studied. The ray method with complex eikonals is used to construct a mode of this sort; the Lorentz lemma is used to calculate the excitation coefficients. The distinctive feature of the Lorentz lemma method is that it permits comparison of different excitation mechanisms for each mode. As examples, consideration is given to the excitation of inhomogeneous (along-the-path) plane and spherically symmetrical waveguides using weak regular (local) inhomogeneities.