Phase conjugation metamaterials: particle design and imaging experiments

We present simulation and experimental results demonstrating the effectiveness of phase conjugation or, equivalently, time reversal metamaterials for imaging applications. Split-ring resonators are loaded with varactor diodes to enable straightforward, easy-to-fabricate phase conjugation metamaterial unit cells. These cells are improved upon to allow either completely wireless operation or more efficient phase conjugate signal generation through the use of active loading elements. The metamaterials are demonstrated experimentally to produce time reversed signals with useful properties. An array of metamaterial cells is then constructed and shown to act as a negatively refracting imaging system.