Sub-wavelength imaging at radio frequency

A slab of material with a negative permeability can act as a super-lens for magnetic fields and generate images with a sub-wavelength resolution. We have constructed an effective medium using a metamaterial with negative permeability in the region of 24MHz, and used this to form images in free space of radio frequency magnetic sources. Measurements of these images show that a resolution of approximately lambda/64 has been achieved, consistent with both analytical and numerical predictions.