Time-domain study of vortexlike interface mode in metamaterials

The properties of vortexlike interface mode in metamaterials are experimentally studied using time-domain measurement. Vortices are illustrated in the interface between a conventional right-handed transmission line (RH TL) and a composite right/left-handed transmission line (CRLH TL). Time-domain experiment obtained the phase velocities of the two lines, which agrees well with the simulation and theoretical results. The group delay from the CRLH TL to the RH TL is experimentally shown much longer than that of the conventional microstrip coupler, which indicates that vortex mode leads to slow propagation.