Automated Design of a Broadside-Radiating Linearly Polarized Isotropic Metasurface Antenna

We present the automated design of a broadside-radiating metasurface antenna. The design is carried out by employing a continuous isotropic Impedance Boundary Condition through an optimization procedure based on the equivalent surface current only. A modified gradient-descent optimization algorithm is applied to minimize an objective function that incorporates both realizability and far field requirements. The antenna is then implemented by a suitable arrangement of circular unit cells, selected from a database of precomputed shapes. This procedure is applied to the design of a broadside-radiating, linearly polarized circular metasurface antenna working at 23 GHz, with size
$\approx 12\lambda$
. The obtained design is then validated with commercial software simulations.