Polarization Reconfiguration of a Millimeter-Waves Antenna using the Optical Control of Phase Change Materials

We present the integration of Germanium Telluride (GeTe), a phase change material (PCM), within a conventional patch antenna operating in the millimeter wave domain (~ 30 GHz). The GeTe is integrated within the four corners of a metallic patch antenna, which is excited by a microstrip line. The phase changes between the insulating (OFF) and metallic (ON) states of GeTe will be controlled using shorts ultraviolet (UV) laser pulses. That allows the reconfigurability of the device between a linear polarization (LP), a left hand circular polarization (LHCP) and a right hand circular polarization (RHCP). Simulated results of antenna show total efficiencies up to 75 % for the circular polarization (CP) and a 3 dB bandwidth of axial ratio (AR) over 350 MHz around 29.5 GHz.