Realization of broadband polarization-insensitive negative refraction using water-based metamaterial

We propose a water-based metamaterial to realize the broadband polarization insensitive negative refraction. The designed metamaterial exhibits the multiple resonances in broadband region and displays negative permittivity and permeability simultaneously with a broadband negative refractive index. Simulated result shows that two separated wide bandwidths of negative refractive index are formed at 12.5-22.7 GHz, and 26.2-28.0 GHz, and the relative bandwidths of which are 58.0%, and 6.7%, respectively. In addition, beam shifting simulation is carried out to verify the retrieved effective refractive index from the scatter parameters, and the calculated results based on beam shifting simulation are agreed well with the retrieved effective refractive indices. Finally, the microwave measurement is performed to exam the simulated and calculated results, and three results of simulation, calculation, and measurement are consistent with each other. The design using water-based metamaterial provides an alternative approach to realize a broadband negative refraction.