mm-Wave Surface Acoustic Wave Filter based on Hexagonal Boron Nitride

We show that the operating frequency of surface acoustic wave filter can be significantly improved by adopting an emerging two-dimensional material: hexagonal boron nitride. Electromechanical properties estimated from first principles' analysis revealed that the material has the potential to realize RF filters in mm-Wave. The following piezoelectric simulation demonstrated an operation frequency as high as 36 GHz, which corresponds to Ka-band (from 26.5 to 40 GHz), with the insertion loss of 3 dB. This was achieved with the 150 nm period interdigital transducer on hexagonal boron nitride. Fabricating this scale of metal gratings is not very difficult with advanced lithography technology. As such, a low-power RF filter for 5G and beyond can be realized with the surface acoustic wave of hexagonal boron nitride.