We investigated surface acoustic wave (SAW) filters composed of interdigital transducers with control gates formed on AlGaN/GaN heterostructures. The contribution of SAWs appeared in the rf characteristics of the SAW filters when reverse-bias voltages were applied to the control gates and the GaN channels were depleted. We also observed higher-frequency signals due to SAWs in transducers with positively-biased control gates. These results suggest that SAW-based functional devices are achievable by employing transducers in which rf signals for exciting SAWs and control signals for modulating SAW properties are applied to different terminals.
ASJC Scopus subject areas
- Physics and Astronomy (miscellaneous)