Subwavelength Microwave Imaging System using a Negative Index Metamaterial Lens

Abstract

This paper describes the design of a subwavelength microwave imaging system using a negative index metamaterial (NIM) lens for nondestructive evaluation (NDE) applications. The imaging system consists of a split ring resonator (SRR)-wire based NIM lens, operating at 6.3 GHz, used in conjunction with a homodyne detection system. Simulation studies of the unit cell design are presented followed by experimental verification of left-handed focusing by the NIM lens with a focal spot of size 0.65λ. A subwavelength hole of diameter 0.25λ in a glass fiber reinforced polymer (GFRP) sample is imaged at a stand-off distance of 1.67λ using the proposed system. High SNR and preservation of polarity and phase information associated with synchronous detection provides a NIM lens imaging system that can be used in the field for rapid inspection at large standoff distances.