Interdigital transducer
An interdigital transducer is a device that consists of two interlocking comb-shaped arrays of metallic electrodes. These metallic electrodes are deposited on the surface of a piezoelectric substrate, such as quartz or lithium niobate, to form a periodic structure.
IDTs primary function is to convert electric signals to surface acoustic waves by generating periodically distributed mechanical forces via piezoelectric effect. The same principle is applied to the conversion of SAW back to electric signals. These processes of generation and reception of SAW can be used in different types of SAW signal processing devices, such as band pass filters, delay lines, resonators, sensors, etc. IDT was first proposed by Richard M. White and Voltmer in 1965.
