For metamaterialsMetamaterial, to date, one of the most important research directions is how to construct them effectively since natural materialsNatural materials with double negative properties have not been found. The development of metamaterialsMetamaterial can be traced back to EMTEffective medium theory (EMT). EMTEffective medium theory (EMT) refers to an analytical method of using a continuous and uniform mediumMedium to replace non-uniform composite mediaMedium, making it easier to investigate physical properties. This method was initially used to study the physical properties of composite mediaMedium, including gaseous, liquid, solid, and mixed states of matters.