Design of a Sub-THz Phased Array Antenna Based on VO₂ Switches for Beamforming

In this work, a reconfigurable phased array antenna is designed for sub-terahertz (sub-THz) beamforming using vanadium dioxide (VO<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf>) switches. As VO<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> exhibits a thermally induced phase transition, a thermal management strategy is incorporated at both the unit-cell and array levels to suppress thermal crosstalk. A 2-bit true time delay (TTD) phase shifter operating at 105 GHz demonstrates the worst-case insertion loss of 5.88 dB. When integrated into a 4-element antenna array, the system achieves beam steering in the H-plane over an angular range of –18° to 18°.