You can download it here

ABSTRACT : We present the integration of GeTe (Germanium Telluride), a phase change material (PCM),
within the structure of an antenna operating in the millimeter wave domain (∼ 30 GHz) in order to make
it reconfigurable in three polarizations: a linear polarization (LP), a left hand circular polarization (LHCP)
and a right hand circular polarization (RHCP). The device is based on a conventional patch antenna excited
by a microstrip line with the GeTe material integrated into the four corners of the patch. The phase change
between the insulating (OFF) and metallic (ON) states of this material is controlled by direct irradiation
using ultraviolet (UV) short laser pulses and allows the reconfigurability of the antenna between an LP,
an LHCP and an RHCP. The measured performances of the fabricated device show axial ratios of less
than 3 dB over a 400 MHz of bandwidth around 29.5 GHz with total efficiencies up to 75 % for the
circularly polarized configurations and a maximum gain up to 8.3 dBi for the linear polarization states.