Answer the following about devices that use surface acoustic waves, for 10 points each.
[10e] Surface acoustic waves are used in high Q-factor resonators that operate at higher frequencies than this common crystal resonator frequently found in wristwatches.
ANSWER: quartz [or SiO2]
[10m] In phones, SAW devices are often used as this kind of component, since they are very space-efficient and have high roll-off. A class of these devices is optimized for a flat transfer function.
ANSWER: filters [accept specific kinds of filters, such as digital filters or bandpass filters or Butterworth filters]
[10h] Surface acoustic waves are also useful in photonic circuits, whose medium of choice is this three-layered semiconductor substrate. Energy-efficient transistors may use the “fully-depleted” variant of this design, in which a “buried oxide” prevents leakage current.
ANSWER: silicon on insulator [or SOI; accept FD-SOI]
<S, Physics>