Components for Acoustic Surface Waves Based on Narrow-Strip Cutoff Sections

A new class of components for acoustic surface waves has been developed which is based on a simple structure that is equivalent to a small section of below-cutoff transmission line. The components include power splitters, directional couplers, nonreflecting delay-line taps, attenuators, resonant cavities and certain types of filters. They have the additional advantage of working on any substrate, piezoelectric Or not. The theory for each of these components has been developed with the aid of accurate equivalent networks, taking into account the modifications introduced by the finite width of the surface wave beam. Limited measured results taken so far agree well with the theory.