High-power and low-profile metamaterials for reflectarray based on $\epsilon $-negative layer in X-band

The low-profile reflectarray is proposed in this Letter based on the $\epsilon $epsilon-negative metamaterial, whose units are mainly designed as two types for aperture phase-tuning. A tri-layer structure is investigated, which is composed of a $\epsilon $epsilon-negative metamaterial sandwiched by two identical high-$\epsilon _r$epsilon r dielectric slabs, and features characteristics of high power capacity, energy tunnelling and robustness against the incident angle of the electromagnetic wave. The simulation and experiment sufficiently demonstrated that the structure obtains high transparency rate at a relative bandwidth of 30$\%$%, as well as a 1-bit phase shift of 0$<^>\circ $degrees and 180$<^>\circ $degrees is achieved, which makes it potentially high-power microwave spatial phase shifter and the linear-polarisation radiator for reflectarray.