Planar magnetoinductive lens for three-dimensional subwavelength imaging

Abstract

A planar near-field magnetoinductive lens operating in the microwave range is presented. Theproposed device consists of two parallel planar arrays of metallic broadside coupledsBCdsplit-ringresonatorssSRRsd, or BC-SRRs. The power coming from a point-like source located in front of thelens is focused into a receiver located in free space beyond the lens. This focus is clearly separatedfrom the back side of the lens, and has a size that is an order of magnitude smaller than the freespace wavelength of the incoming field. The imaging properties of the device relies mainly on theexcitation of magnetoinductive surface waves on the BC-SRR arrays. By simply scaling theBC-SRRs’ size, as well as the arrays periodicity, the operation frequency of the device can be tunedin a wide frequency range. Thus, the proposed design is potentially useful for many applicationsranging from megahertz to terahertz.