Phase Coding Framework of Digital Metamaterials Based on Convex Optimization

Accurate phase coding is a key to meet the demand of practical problems for digital metamaterials. In this work, we propose a novel phase coding method based on convex optimization for digital metamaterials. A general nonconvex problem of metamaterials beam synthesis is reformulated into a convex optimization problem. The quasi-Newton optimization method is used to obtain the solution of the convex optimization problem. Then a shortest-distance discretization method maps the obtained solution into a selectable phase. A digital metamaterials example is presented to demonstrate the performance of the proposed method in comparison with conventional genetic algorithm.