Experimental verification of overcoming the diffraction limit with a volumetric Veselago-Pendry transmission-line...

A fully printed Veselago-Pendry lens (isotropic n=-1, epsilon(r)=-1, mu(r)=-1) is presented which is based on transmission-line metamaterials. The lens is constructed in a parallel-plate environment at 1.569 GHz and without any embedded sources and achieves a resolution better than the diffraction limit (full width half power of 0.235 lambda). Because the lens is low loss (<0.3 dB per unit cell), the focused fields are dominated by the evanescent components which dictates that subwavelength tightening of the beam is achieved only in the transverse and not the longitudinal direction. The demonstrated lens is quarter-wavelength thick thus allowing ample "working distance" between the subject/image and the lens.