Experimental visualization and group velocity evaluation of wave packet on left-handed transmission line

Experimental visualization of a wave packet traveling along a composite right/left-handed transmission line in its left-handed frequency band is successfully demonstrated. The demonstration is based on the RF wave visualization scheme of live electrooptic imaging technique in conjunction with composition of Fourier component video images. Propagation speed of the wave packet, i.e. group velocity was evaluated spatially on its propagation video. In addition, its frequency dependence, i.e. group velocity dispersion was characterized. Their comparison with those deduced from S-parameter measurement data was discussed.