Spherical metasurface for radiation pattern control

We present a method to reshape the radiation pattern of an antenna into an arbitrarily defined pattern through the use of a spherical impedance metasurface that completely encloses a source. We derive analytical equations to determine the sheet impedance distribution of the spherical metasurface to realize a 4π steradian desired electric field image pattern. To demonstrate the performance, we reshape the radiation pattern of a small dipole current source into a near-field pattern taking the shape of a nautical anchor.