Dispersion characterization of CRLH transmission lines by electro-optic visions of forward/backward waves

A novel experimental approach is proposed to characterize the dispersion properties of radio frequency (RF) waves in metamaterial structures. The approach is based on wave analyses in the space domain and is provided by RF wave visualization through the live electro-optic imaging scheme. It was successfully demonstrated to visualize forward/backward RF waves in composite right/left-handed transmission lines. The RF wave imagery is shown to be useful for determining right/left-handed frequency ranges as well as evaluating their propagation constants. The derived dispersion diagrams were compared with those obtained from unwrapped S21 phase data.