Edge effects in axial arrays of circular rings

A boundary value problem is solved for the current induced by any source, in particular for an incident plane wave, on any number of identical rings that are arranged to form an axisymmetric, linear array. The net aperture distribution along the finite array is approximated by a combination of three physically-identifiable components: a term from the related infinite array plus contributions from two independent edge-effect waves that originate from each of the two ends. However, if individually resonant loops are closer than a critical spacing, the entire structure exhibits a wild resonance and the simple approximation becomes invalid.