Ku-Band Alscn-on-Diamond SAW Resonators with Phase Velocity Above 8600 M/S

In this work, an Aluminum Scandium Nitride (AlScN) on Diamond Sezawa mode surface acoustic wave (SAW) platform for RF filtering at Ku-band (12–18 GHz) is demonstrated. Thanks to the high acoustic velocity and low-loss diamond substrate, the prototype resonator at 12.9 GHz achieves a high phase velocity <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$(\nu_{\mathrm{p}})$</tex> of 8671 mis, a maximum Bode-Q of 408, and coupling coefficient <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$(k_{\mathrm{e}\mathrm{f}\mathrm{f}}^{2})$</tex> of 2.1 %, outperforming high-velocity substrates such as SiC and sapphire by more than 20% in velocity. Resonators spanning 8 to 18 GHz are presented. The platform's high power handling above 12.5 dBm is also experimentally validated.