Light-Weight Base Station Antenna with Artificial Wire Medium Lens
  In this paper we study the possibility of utilizing a loaded wire medium as an artificial material for beam shaping element in base station antenna applications. The wires in the lattice are loaded with a proper capacitive impedance to come up with a structure effectively operating as a dielectric lens at the UMTS (Universal Mobile Telecommunications System) frequency range. It is proven with full-wave simulations that the interpretation of a finite size wire lattice as a dielectric lens is physically sound even with a moderate number of lattice periods. A prototype having a mechanically reconfigurable beam width is constructed and measured. It is shown that very promising performance can be achieved with a rather simple structure and a cheap manufacturing process. 
Pekka Ikonen, Mikko Karkkainen, Constantin Simovski, Pavel Belov, and   Sergei Tretyakov