Abstract
With the advent of metamaterial the approaches of automated extraction of effective parameters for a metamaterial have recently attracted considerable attention among researchers. Evaluation of refractive index has received huge importance especially for the left-handed metamaterial. This communication presents a new simplified equation for the direct retrieval of refractive index from the transmission and reflection co-efficient. Refractive index is calculated from the new equation for two recently published metamaterials. The resultant curve for the proposed method shows good conformity with the classical NRW-method and shows a result closer to that achieved using the TR-method. In addition, a comparative study of the three methods is presented.