Microwave Applications of Photonic Crystals

—We have demonstrated guiding and bending of electromag- netic (EM) waves in planar and coupled-cavity waveguides built around three-dimensional layer-by-layer photonic crystals. We observed full transmission of the EM waves through these waveguide structures. The dispersion relations obtained from the experiments were in good agree- ment with the predictions of our waveguide models. We also reported a resonant cavity enhanced (RCE) effect by placing microwave detec- tors in defect structures. A power enhancement factor of 3450 was measured for planar cavity structures. Similar defects were used to achieve highly directional patterns from monopole antennas.