Thin Planar Metasurface Lens for Millimeter-Wave MIMO Applications

This communication presents a very thin metasurface (MS) planar lens for millimeter-wave (mm-wave) MIMO applications. The MS planar lens consists of array of mm-wave resonators providing varying phase response to transform the phase profile of the electromagnetic wave propagating through this array. Each resonator consists of two identical layers having substrate separated by an air gap of
${h=0.8}\,\,{\text {mm}}$
and is
${4} \,\,{\text {mm}}{\times } 4\,\,\text {mm}$
in size. The MS lens having a focal length of
$f=12\,\,\text {mm}$
is loaded to a three-port proximity fed antenna array to operate at 27.5–32 GHz. The designed lens is polarization-insensitive and can be used with any polarization. The three-port antennas with the MS lens is fabricated and tested, and the measured results have confirmed a beam scanning of ±15° with a peak gain of 20.2 dBi for port-2.