A SIMPLE EQUIVALENT-CIRCUIT FOR INTERDIGITAL TRANSDUCERS BASED ON THE COUPLED-MODE APPROACH

The coupled-mode approach is a powerful tool for analyzing SAW periodic structures such as reflectors and interdigital transducers. In this paper, the relations among the terminal quantities at two acoustical ports and one electrical port of an interdigital transducer (IDT) are derived from coupled-mode equations, and a simple distributed-parameter equivalent circuit representing the entire IDT is proposed. A few examples of applications of this equivalent circuit to analysis of SAW devices are also presented.