Comparison of Optimization Approaches to Design Reactively Loaded Antenna Arrays

This paper compares methods to design sparse grating-lobe-free reactively-loaded antenna arrays using different optimization approaches. Three approaches are based on optimization on a Riemannian manifold, and one utilizes the Optenni Lab software. In addition, we compute the fundamental bounds of the optimization problems using semi-definite relaxation. Demonstrations with a connected patch-diamond antenna array show that the scan loss is minimized when the reactive loads are optimized by maximizing the antenna array's minimum main beam gain within the beam-steering sector.