  For a narrow slit structure backed by a conducting strip which is taken as a
representative example of an aperture-body resonance (ABR) problem, the
transmission resonance condition (i.e., condition for maximum power
transmission) and the transmission width (i.e., normalized maximum transmitted
power through the slit) are found to be the same as those for narrow slit
coupling problem in a thick conducting screen, which is designated as a
transmission-cavity resonance (TCR) problem. From a viewpoint of equivalent
circuit representation for the transmission resonance condition and the
funneling mechanism, the ABR and the TCR problems are thought to be essentially
of the same nature.

Optics