1990 IEEE Ultras. Symp.
an icon of Jeanette Danicki's paint

Research domain of E. Danicki and ...

Spectral Theory of Interdigital Transducers

and other papers

SAW devices - theory & experiment

Surface acoustic waves (SAW) devices are electronic components: filters, resonators, and delay lines exploiting surface acoustic waves in piezoelectric crystals.
Interdigital transducer (IDT) converts electronic signal into SAW, which, propagating 100000 times slower than electromagnetic waves, deliver signal delay in the device.
Signal filtering is performed by apodized IDT during electric to SAW signal conversion (or back conversion by another IDT). This is transversal filtering (SAW signal is sampled by IDT fingers).
SAWs can be partially reflected by small perturbation of the crystal surface (shallow grooves or thin metal strips, for instance). Effective SAW reflection structures are systems of periodic grooves or strips. They are distributed reflectors applied in SAW (Fabry-Perot) resonators. In another type of double channel resonators, reversing multistrip couplers (MSC) are exploited to reflect SAWs with simultaneous track-changing between two SAW channels.
The SAW technique is similar to microwave technique, with waveguides of thousands of SAW wavelengths long. SAW devices are exploited in many electronic systems, home TV sets, cellular phones, satellites, radars, etc.