Comparative Analysis of Switching Efficiency of GeTe and VO₂ based RF Switches

Phase change materials (PCMs) are extensively employed in switchable, reconfigurable, and tunable devices operating from DC to optical frequencies because of the substantial change in their electrical and optical properties during reversible insulator to metal phase transition. Germanium telluride (GeTe) and Vanadium dioxide (VO <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> ) are the most promising PCMs for microwave applications because of fast switching speed and ease of integration. This work reports a comparative electrothermal analysis of GeTe and VO <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> based indirectly heated RF switches integrated with microheaters using an equivalent circuit model of heat propagation. For equivalent RF performance, we analyze the relative power dissipation in GeTe and VO <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> switches as a function of switching frequency and device dimensions. From the analysis we find that GeTe RF switches are relatively more efficient than VO <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> RF switches up to a crossover switching frequency (~ 50-82 kHz) beyond which VO <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> switches are more efficient.