McKinley, A. F.White, ThomasMaksymov, I. S.Catchpole, Kylie2015-09-212015-09-210021-8979http://hdl.handle.net/1885/15595Interest in the electromagnetic properties of loop structures has surged with the recent appearance of split-ring resonator meta-materials (SRRs) and nano-antennas. Understanding the resonances, anti-resonances, and harmonics of these loops is key to understanding their response to a wide range of excitation wavelengths. We present the classical analytical solution for the input impedance of a loop structure with circumference on the order of the wavelength, and we show how to identify these resonances from the function. We transform the classical solution into a new RLC formulation and show that each natural mode of the loop can be represented as a series resonant circuit, such that the full response function can be resolved by placing all of these circuits in parallel. We show how this formulation applies to SRRs.This work has been partially supported by the Australian Research Council and the Australian Solar Institute.http://www.sherpa.ac.uk/romeo/issn/0021-8979..."Publishers version/PDF may be used on author's personal website, institutional website or institutional repository" from SHERPA/RoMEO site (as at 21/09/15). Copyright 2012 American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics. The following article appeared in Journal of Applied Physics and may be found at https://dx.doi.org/10.1063/1.4764104Keywords: Classical solutions; Electromagnetic properties; Excitation wavelength; Input impedance; Loop structure; Natural modes; Response functions; Ring resonator; Split-ring resonator; Loop antennas; Metamaterials; Resonant circuits; Resonance2012-11-1210.1063/1.47641042016-02-24