Control of surface states of planar metamaterial based on moire effect
The possibility of continuous tuning of the spectral properties of two types of planar metamaterials based on the moire effect by changing their geometric parameters is demonstrated both experimentally and numerically. It is shown that for a one-dimensional moire metamaterial obtained by superposition of two microstrip photonic crystals with close periods, the position of the stop band in the spectrum can be controlled by changing these periods. For the two-dimensional moire metamaterial formed by two identical periodic crossed structures with hexagonal symmetry, the ability to control the frequency of the surface state mode by changing the crossing angle of these structures relative to each other has been experimentally and numerically shown. It is numerically demonstrated that if the moire metamaterial is irradiated by the horn antenna, a surface wave propagating in the metamaterial plane appears in all directions beginning from its intersection point with the axis of the incident wave beam. From the application point of view, moire metamaterials of this type can be considered as promising prototype of microwave filters, whose spectral properties can be continuously and smoothly mechanically rearranged.