Capacitively Loaded Loop as Basic Element of Negative Permeability Meta-material

A simple one-dimensional meta-material which exhibits negative permeability within a finite frequency band is proposed in this paper. Instead of recently introduced split-ring resonators, this structure comprises an array of the capacitively loaded small loop antennas. Due to resonant behaviour of the antenna current, intensity of the magnetic field of the incoming plane wave may be locally decreased yielding a stop-band with negative effective permeability. Theoretical analysis was verified by measurements of the transmission coefficient of experimental structures in free space and in rectangular waveguide, in 10 GHz frequency band. The developed structure was also combined with previously reported negative permittivity wire structure and left-handed (backward wave) properties were observed.