Current-Based Full-Wave Synthesis of Reactive Metasurface Antennas

In this work we present a novel optimization algorithm for the design of metasurface antennas. It focuses on the full-wave synthesis of an equivalent surface current distribution from the given bounds on the radiated field. The algorithm ensures that the resulting current can be realized with a reactive impedance profile. A modified gradient-descent optimization algorithm is applied to a specific objective function that incorporates both physical and far field requirements. The radiating surface is modelled by a scalar impedance boundary condition and the electromagnetic problem is solved numerically with the Method of Moments. This procedure was applied to the design of an electrically large circular metasurface antenna at a frequency of 32 GHz.