Visual Observations of Characteristic Behaviors of RF Waves in CRLH-TLs and Their Applications to Dispersion Characterizations

A novel experimental approach is proposed and demonstrated for visually observing characteristic behaviors of radio frequency (RF) waves in metamaterial structures in real time. Space domain analyses of observed wave images are also successfully applied to dispersion characterizations of the structures. These unique functionalities are provided by the RF wave visualization capability of the live electro-optic imaging scheme. Not only successful visualizations of forward and backward propagating RF waves in composite right/left-handed transmission lines are demonstrated, but visual investigation also takes place on their characteristic wave features at boundaries and in the extreme short wavelength region. The RF wave imagery is shown to be useful for determining right/left-handed frequency ranges and evaluating their propagation constants. The derived dispersion diagrams are discussed and compared with those conventionally obtained from unwrapped S₂₁ phase data.