English: Figure 2 Part of the left-handed metamaterial array configuration, which was constructed of copper split-ring resonators and wires mounted on interlocking sheets of fiberglass circuit board. The total array consists of 3 by 20 by 20 unit cells with overall dimensions of 10 by 100 by 100 mm.

Split-ring resonator consisting of an inner square with a split on one side embedded in an outer square with a split on the other side. Split-ring resonators are on the front and right surfaces of the square grid, and single vertical wires are on the back and left surfaces. References:

1. Chevalier, Christine T.; and Wilson, Jeffrey D.: Frequency Bandwidth Optimization of Left-Handed Metamaterial. NASA/TM--2004-213403, 2004.
2. Wilson, Jeffrey D.; and Schwartz, Zachary D.: Multifocal Flat Lens With Left-Handed Metamaterial. Appl. Phys. Lett., vol. 86, no. 2, 2005.
3. Smith, D.R., et al.: Composite Medium With Simultaneously Negative Permeability and Permittivity. Phys. Rev. Lett., vol. 84, no. 18, 2000.
4. Shelby, R.A., et al.: Microwave Transmission Through a Two-Dimensional, Isotropic, Left-Handed Metamaterial. Appl. Phys. Lett., vol. 78, no. 4, 2001.