Finite-difference time-domain simulations of approximate ground-plane cloaks

In this paper we use a coordinate transformation to create a cloak that covers a triangular-shaped conducting object placed on a ground plane. A finite-difference time-domain (FDTD) algorithm that uses non-orthogonal mesh cells (NFDTD) is initially utilized to test the full cloak. Using the coordinate transformation method, we have designed a ground-plane cloak that is an approximate version of the full scale cloak. Despite its simple structure, which consists of only 16 blocks of all-dielectric materials, the approximate cloak is found through FDTD simulations to work very well when an incident pulse is impinging on an object placed on a flat ground plane. The scattering signature is significantly suppressed and we expect such cloaks to be fairly easy to implement in reality.