Topology optimization of patch-typed left-handed metamaterial configurations for transmission performance within the radio frequency band based on the genetic algorithm.

For the requirement of broadband transmission with low attenuation within the radio frequency band, a topology optimization model of microstructure configuration design of patch-typed left-handed metamaterials is established, with the objective function defined by the ratio of the mean attenuation to the absolute left-handed bandwidth; then a genetic algorithm based solution method and flow chart of the topology optimization are presented. An improved electromagnetic simulation analysis method is used to obtain accurate equivalent electromagnetic parameters from the S-parameter retrieval process. Three patch-typed microstructure configurations are given according to the results of topology optimization designs for different lattice sizes, and the transmission performance indicators of these creative configurations are computed and analyzed by numerical simulation. The contrast of the design results shows that a U-shaped-like structure of half a unit cell height exists among all these optimum configurations. It is found through a further analysis that the distribution of conduction currents of U-shaped-like structures is the key to broadband transmission with low attenuation. Finally, a new topology optimization design with the perimeter constraint is proposed to solve the problem in the manufacturing process for checkerboard-typed lattices from these configurations. [ABSTRACT FROM AUTHOR]