Comparative analysis of edge- and broadside-coupled split ring resonators for metamaterial design - Theory and experiments (original) (raw)

2003, IEEE Transactions on Antennas and Propagation

This paper develops a quasi-analytical and self-consistent model to compute the polarizabilities of split ring resonators (SRRs). An experimental setup is also proposed for measuring the magnetic polarizability of these structures. Experimental data are provided and compared with theoretical results computed following the proposed model. By using a local field approach, the model is applied to the obtaining of the dispersion characteristics of discrete negative magnetic permeability and left-handed metamaterials. Two types of SRRs, namely, the so-called edge coupled-and broadside coupled-SRRs, have been considered. A comparative analysis of these two structures has been carried out in connection with their suitability for the design of metamaterials. Advantages and disadvantages of both structures are discussed. Index Terms-Left-handed media (LHM), metamaterials, negative magnetic permeability, negative refractive index, split ring resonators (SRRs). I. INTRODUCTION T HE term metamaterial is presently applied to artificial discrete media showing "exotic" electromagnetic properties at microwave frequencies. These media include artificial plasmas [1]-[3] (which exhibits negative dielectric permittivity below their plasma frequency), negative magnetic permeability media (NMPM) [4] and left-handed media (LHM) [5], [6] (these are media with simultaneously negative electric permittivity and magnetic permeability). Artificial plasmas are well-known materials that can be built up, for instance, by using a regular array or mesh of wires and/or metallic plates [1]. The electromagnetic behavior of these wire/plate-made artificial plasmas is well understood, their electromagnetic models leading to accurate predictions in most cases [1]-[3]. In practice, an artificial NMPM has been recently demonstrated making use of small resonant particles , the so-called split ring resonators (SRRs) introduced in [4], arranged in a convenient way. Discrete LHM, in turn, have been developed by combining Manuscript