An improved boolean differential evolution algorithm and its application in design of broadband terahertz absorber based on concentric graphene rings

Abstract

The sandwich-type metamaterial absorber (MA) based on discretely patterned graphene has potential for broadband absorption in the terahertz (THz) region. In this paper, a broadband THz MA with concentric graphene rings is designed using an improved boolean differential evolutionary (IBDE) algorithm, which is based on three strategies for improvement, including the identification of the optimal control parameters using the Taguchi method, the Taguchi crossover operator, and a restarting strategy. The performance of the IBDE has been validated against 23 benchmark functions, demonstrating impressive capabilities in both convergence speed and local search. The designed MA, which is backed by a thin film of vanadium dioxide, has the ability to switch between functioning as an absorber and acting as a transparent insulating dielectric. Moreover, the equivalent conductivity of the patterned graphene is also derived to establish the equivalent circuit model of the designed MA. The proposed IBDE shows promise for designing high-dimensional discrete graphene patterns aimed at broadband absorption applications.