The GaN/SiC Heterostructure-based Hydrogen SAW Sensor Operating in GHz Range

In this work we demonstrate the fabrication process and electrical characterization of GaN/SiC heterostructure-based surface acoustic wave filters for highly-sensitive hydrogen sensors. In the acoustic propagation path, palladium metal is used as a hydrogen sensing layer. The influence of this layer on SAW velocity is measured. The impact of second-order effects on SAW filter properties is discussed. Two different interdigitated transducer (IDT) topologies are investigated in order to achieve the low insertion loss and high attenuation of triple transit echo (TTE). Finally, the sensory performance of designed delay line SAW oscillator is demonstrated