Hybrid Genetic Programming for the Development of Metamaterials Designs With Improved Characteristics

The expansion of a hybrid genetic program's (HGP) functionality to allow for the development of broadband two-dimensional metamaterials designs with advanced characteristics is presented. Artificial magnetic conductor (AMC) ground planes and a tunable terahertz absorber generated by the HGP are compared with designs available in the literature. The HGP is shown to produce human-competitive results. The AMC ground planes synthesized by the HGP were found to produce improved results including wider bandwidths and larger reflection coefficient magnitudes than that of the human designs. For one of the designed AMCs, the HGP's bandwidth is 73.3% larger and the minimum reflection magnitude is 1.0% larger than the reference AMC. Similarly, the absorber synthesized by the HGP has larger bandwidths than that of a recently published absorber optimized by random hill climbing. Three bias voltages were tested with the tunable absorber. The bandwidths of the HGP absorber are 23.1%, 37.6%, and 400% larger than the reference absorber, for biases of 4, 2, and 0.5 V/nm, respectively. Four example designs are discussed together with comparative results to illustrate the advantages of the developed HGP-enabled design method.