2D zeroth order resonator with non-planar metamaterial composed of metal rods

A two-dimensional zeroth order resonator (2D ZOR) artificially composed of an array of metal rods is designed. A metal rod material which supports 2D backward waves is fabricated and tested at a 2GHz band. Near field measurement results show negative refractive index characteristics which agree well with simulated results. A ZOR operation with an infinite wavelength is experimentally confirmed by the near field measurement. The ZORs could potentially be used for both radiative and non-radiative applications depending on an appropriate choice of the propagation mode in the medium.