Demonstration of a backward wave in a single split ring resonator and wire loaded finline

A finline-based left-handed transmission line is presented and analyzed. The transmission line is periodically loaded by single split ring resonators and thin wires in order to synthesize a negative permeability and permittivity propagation medium. The propagation properties are computed by means of full-wave frequency analysis of scattering parameters from which the band diagram is derived. A backward wave behavior is predicted and demonstrated unambiguously front ab-initio simulations. The phase front is observed to be in opposite direction with respect to the energy one for a finite five-unit cell X band prototype.