Automated Design and Characterization of a Scalar Metasurface Antenna Radiating a Linearly-Polarized Broadside Beam

We present the automated design of a broadside-radiating, linearly-polarized metasurface antenna. The design is carried out with a numerical optimization procedure based on the equivalent surface current only. A non-linear conjugate gradient algorithm is applied to minimize an objective function that includes both realizability and far field requirements. A suitable configuration of circular unit cells, chosen from a database of precomputed shapes, is then used to implement the antenna. The proposed antenna has a diameter ≈12λ , working at a frequency of 23 GHz. The obtained design has been validated with commercial software simulations, then prototyped and tested.