Design of left-handed materials with broad bandwidth and low loss using double resonant frequency structure

An element consisting of a spiral inductor loaded by a rectangular loop resonator is newly proposed to achieve double resonant frequencies. An array of such elements is then synthesized periodically to realize left-handed materials that exhibit both negative permittivity and negative permeability. With synthesis of the periodic array, the left-handed material (LHM) is characterized theoretically and numerically and is found to have a broad bandwidth and low loss. In addition, design equations used to calculate the equivalent circuit parameters are given.