Book chapter on Transformation Optics & Antennas

The discrete coordinate transformation is a practical implementation of transformation electromagnetics. It solves the transformation between coordinate systems in a discretized form. This method significantly relaxes the strict requirement for transformation media, and consequently leads to easily-realizable applications in antenna engineering. In this chapter, the discrete coordinate transformation is demonstrated and analyzed from the theory and is proved to provide an all-dielectric approach of device design under certain conditions. As examples, several antennas are presented, including a flat reflector, a flat lens, and a zone plate Fresnel lens. The Finite-Difference Time-Domain (FDTD) method is employed for numerical demonstration. Realization methods are also discussed, and a prototype of the carpet cloak composed of only a few dielectric blocks is fabricated and measured.