Abstract:
A novel and efficient method to overcome the barriers of conventional diffraction limit
using a specially designed metamaterial Split Ring Resonator (SRR) structure as an imaging sensor
at microwave frequency is proposed. The topology of the proposed sensor is ingeniously designed to
identify imaging objects having dimensions much less than the interacting wavelength λ. The split
gap field region of the conventional SRR, used as the sensing region of the imaging sensor, is modified
for enhancing the resolution capacity, by slightly raising the split region of the outer ring structure
perpendicular to the plane of the resonator (Projected Split Ring Resonator — PSRR) which will
reduce the area of the sensing region of the SRR probe considerably. The isolation of the structural
parts of the SRR other than projected split region helps in using the localized evanescent field at the
split region of the PSRR for imaging of minute objects having dimension ranges up to 0.0001λ by
precisely choosing the split gap. The required projection height of the split region and the possible
resolution limits of the PSRR sensor probe are evaluated by simulation. Experimental 2-dimensional
sub-wavelength images obtained for various dielectric objects using a typical PSRR test probe having
resolution capability up to 0.01λ are also presented.
