Electromagnetic structures with higher symmetries

Here, we introduce the concept of higher symmetries and their implications when introduced in electromagnetic periodic structures. It has recently been demonstrated that higher symmetries are able to reduce the dispersion of periodic structures, to increase their equivalent refractive index, or to create bandgaps that mainly depend on the symmetry of the structure. Their potential applications are in fully metallic reconfigurable phase shifters and filters, flat lenses, and low-dispersive leaky-wave antennas.