Application of illuminating modes concept in modal expansion of elliptical resonator

In the paper an Illuminating Modes (IM) approach as an extension of Spectral Domain Approach (SDA) is presented. IM concept is applied to the case of open microstrip planar elliptical resonator. A modal expansion of currents induced in the structures during illuminating them by a single plane wave is the novelty of the method. As an example of application of the method, we present the results obtained by an examination of two resonators illuminated in two different ways. The amplitudes of current modes induced in the structures are found as well as the scattered fields. All the results yield some new knowledge related to the field phenomena occurring in resonators.