Experimental Study of Transmission and Reflection Characteristics of a Gradient Array of Metamaterial Split-Ring Resonators

A study of a nonuniform metamaterial array consisting of six split-ring resonators of varying diameters is conducted experimentally to measure the transmission and reflection characteristics that arise from asymmetry in the longitudinal direction. Such characteristics are examined and compared with their counterpart symmetric scattering coefficients associated with a uniform split-ring array. In the nonuniform array the ring diameters vary in steps of 0.5 mm, which yields a gradient geometry. Inserting the nonuniform array in an X-band waveguide operating below cutoff provides a transmission band wider than that obtained from the uniform array.