Free-space focused-beam characterization of left-handed materials

We used a broadband, free-space, focused-beam system to measure the transmission and reflection in left-handed-material (LHM) slabs. The samples were made of alternating patterns of copper wires and split-ring resonators on Rogers 5880 substrates separated by Rohacell(TM) spacers. The measured data show very good agreement with numerical simulations. The measured insertion loss of this structure was -1.1 dB/cm at the LHM pass band. Simulations suggest that the loss may be attributable to the finite conductivity of the copper patterns. (C) 2003 American Institute of Physics.