For an electromagnetic plane wave that is normally incident upon an aperture or aperture array in an infinite perfectly electrical conducting plane, the validity of the general expression for the transmission cross-section as a measure of the transmitted power through the aperture or aperture array is investigated for the following two cases: first, for a single transmission resonant aperture (TRA) such as a complementary split ring resonator, which is larger than Bethe's small magnetic dipole;

more »

... second, for the finite periodic array of a non-TRA such as the usual circular or rectangular apertures aligned along the E-plane direction corresponding to the parallel configuration in terms of the terminology of the electrical dipole array theory. To validate the investigation, the proposed expression is applied to a general aperture distribution, and the results are compared with the results obtained using the Rao-Wilton-Glisson method for the above two cases of aperture distributions. Consequently, it is discovered that for the finite array of non-TRAs, the E-plane aperture array produces an improved directive for the field than the H-plane aperture array used as the Huygens source. This observation may aid in understanding the underlying physics of the two-slot model for rectangular microstrip antennas and the basic 1D linear array as a minimal system exhibiting the extraordinary optical transmission phenomena in 2D aperture arrays.