Surface acoustic wave
From Free net encyclopedia
A surface acoustic wave (SAW) is an acoustic wave traveling along the surface of a material having some elasticity, with an amplitude that typically decays exponentially with the depth of the substrate. This kind of wave is commonly used in piezoelectric devices called SAW devices in electronics circuits. SAW devices are employed as filters, oscillators and transformers based on the transduction of acoustic waves.
Electronic devices employing the SAW normally utilize one or more interdigital transducers (IDTs) to convert acoustic wave to electrical signal and vice versa utilizing the piezoelectric effect of certain materials (quartz, lithium niobate, lithium tantalate, LGS etc). These devices are fabricated utilizing common processes used in the manufacture of silicon integrated circuits.
SAW filters have enjoyed successful application in the booming cellular telephones market and provide significant advantages in performance, cost, and size over other filter technologies (digital signal processors, quartz crystals (bulk wave) , LC-filters, and waveguide filters).
Significant research has been done in the last 20 years in the area of surface acoustic wave sensors. Sensor applications include all areas of sensing (such as chemical, optical, thermal, pressure, acceleration, and biological). SAW sensors have seen limited commercial success, but are commonly commercially available for some applications such as touchscreen displays.
External links and references
- SAW Filter Information - Custom SAW Filter Manufacturing