Design of a subwavelength flat focusing lens and simulation of its performance in the presence of biological tissues at millimetre waves

A flat, focusing, metamaterial lens, operating at 60 GHz was designed using 3-layer elements consisting of metallic bars and split ring commutators. Its free space focal length is 15 mm. We also simulated a system where a pair of such lenses is placed on either side of biological tissue consisting of a 2-layer skin-blood structure. When excited by a patch antenna, the directivity is enhanced by 9.5 dB.