Transmission properties of composite metamaterials in free space

We present free-space microwave measurements on composite metamaterials (CMMs) consisting of split ring resonators (SRRs) and wires on alternating boards, also known as left-handed material (LHM). Our experiments are based on a type of CMMs with unique configurations and the transmission measurements performed in free space exhibit a pass band extending from 10.5 to 13.5 GH. The widely belief of the pass band is that the stop bands of the SRRs alone and the wires alone constitute a clear demonstration of left-handed (LH) behaviour. The LH behaviour only take place in the medium with simultaneously negative permittivity epsiv, and permeability mu, also called double negative materials.