Abstract
The study of periodic structures having electromagnetic functions has undergone rapid development recently, and both theoretical and practical achievements are garnering increasing attention. These electromagnetic structures, called metamaterials, exhibit photonic and electric bandgap phenomena, where intrusion of electromagnetic waves of certain frequencies into a periodic structure is inhibited. Wave bandgap phenomena can also be observed in elastic waves. Topology optimization has been successfully utilized for the design of such bandgap structures, based on the concept of eigen-frequency optimization inside a predefined basic lattice. This study proposes a novel topology optimization method for periodic microstructures of electromagnetic materials using the concept of propagation behavior to formulate design problems. The proposed method is also capable of automatically generating 2D periodic photonic bandgap structures without relying on a predefined lattice, and physically reasonable results were obtained.
