Experimental observation of multi-functional plasma-metamaterial composite for manipulation of electromagnetic-wave propagation

Although microwaves are widely used in our daily life, their propagations left free with disordered absorption and scattering most scenes, without any sophisticated controls of paths. Microwave metamaterials have increased regulation options which cloaking is extensively studied, but exploratory aspects so far insufficient for multiple requests wireless-communication availability life space. Here, we show plasma-metamaterial composite device that becomes an absorber, a scatterer, or flattener (including effects) by changing narrow-range microwave frequency (2.6–3.1 GHz, the middle S band). A radio high-power input ranging to 400 W generate plasma vacant space metamaterial array, this creates abnormal permeability (μ) 0<μ<1, while works as dynamic negative- positive-permittivity (ε) medium spatial gradient. In ε–μ parameter region, state negative ε significant source absorbance, dominant small positive value ε. Among them, propagation flattening mainly due condition takes place adequate set μ suitable gradient refractive index. This manipulation experimentally verified monitoring energy propagating microwaves.