Negative-Zero-Positive Refractive Index in a Prism-Like Omega-Type Metamaterial

Negative-zero-positive index refraction was demonstrated numerically on the basis of full-wave analysis of a microstructured omega-type array and experimentally via angle resolved transmission measurement of a prism-type prototype. The experimental results are interpreted in terms of characteristic impedance and refractive index retrieved by a Fresnel inversion technique. The possibility to balance the dispersion characteristics with a negative-zero-positive index is demonstrated over X - and Ku -bands.