Fully-printed S-band SRR/wire NRI lens with reduced wire density

Abstract

An experiment conducted within S-band demonstrates sub-wavelength resolution can be achieved for a negative-refractive-index (NRI) lens constructed from an array of split-ring resonators (SRRs) and a reduced density array of thin wires. Reducing wire density increases the shunt inductance per unit volume without using excessively thin wires or inductive loading. This capability, along with the use of broadside-coupled SRRs, permits NRI lens operation in the low gigahertz frequency regime. The prototype lens achieved 0.23 wavelength resolution at 2.67 GHz. The insertion loss of the lens was estimated to be 4 dB and is attributed to losses in the SRRs.