A Modulated Reactance Spherical Surface Cloak for 3-D Invisibility

Toward practical 3-D invisibility, passive spherical surface cloaking applicable to large, freestanding scatterers is presented. Characterized by a spatially modulated impenetrable tensor surface reactance, a spherical surface cloak converts the incident plane wave on the lit side into surface waves that carry power to the shadow side. Leaky waves of planar wavefronts are continuously shed in the forward direction to remove the shadow behind the sphere. Numerical design and simulation of a 4-wavelength-radius spherical cloak confirm the effectiveness in minimizing scattering in all directions.