Microwave focusing lenses by synthesized with positive or negative refractive index split-ring resonator metamaterials

Metamaterials had been widely investigated in literature and experiment in recent years, because of they are able to produce unusual permittivity and permeability which can be used to improve the performance of conventional devices [1]. Metamaterial structures designed to have simultaneously negative permittivity and permeability are known as left-handed materials (LHM) [2]. LHM produce negative refraction index and generate the backward-wave. LHM can be employed to design transformed lenses with better focusing efficiency than conventional ones. In this paper, we make use of squared split-ring resonators to synthesize a number of lenses. Particularly, we synthesize a negative refraction index lens and a parabolic refraction lens. CST has been employed to demonstrate the performance of the focusing system.