Discrete transformation electromagnetics and its applications in antenna design

Current designs of electromagnetic cloaks are largely based on the use of metamaterials and a technique so-called ¿transformation optics/electromagnetics¿. Free space cloaks require extreme materials which are difficult to implement in practice, however, the theory of ¿transformation optics/electromagnetics¿ offers a useful design tool for antenna engineers in developing novel antennas. In this paper, a method of discrete transformation is proposed, which offers us an easy way to transform the conventional devices to the all-dielectric flat ones. A flat reflector and a flat lens antenna in the free space are designed as examples. Finite-Difference Time-Domain (FDTD) method based simulation results have proved that these simply constructed all-dielectric devices have very nice performances compared with the conventional ones, while have the advantages of flat profiles and small thicknesses.