# Control of surface states of planar metamaterial based on moire effect

## TL;DR

This paper demonstrates the continuous tuning of spectral properties of planar moire metamaterials through geometric parameter adjustments, enabling control over stop bands and surface states for potential microwave filter applications.

## Contribution

It introduces experimental and numerical methods to control surface states in 1D and 2D moire metamaterials by adjusting periods and crossing angles.

## Key findings

- Control of stop band position via period changes in 1D moire metamaterials.
- Experimental and numerical evidence of surface state frequency control in 2D moire structures.
- Surface wave propagation in the plane of the metamaterial when irradiated by a horn antenna.

## Abstract

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.

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Source: https://tomesphere.com/paper/1906.02624