Four variable, two port analysis of surface wave devices

A two-port, four-variable method of analysis is used to predict the reflection coefficient of surface wave metal stripe reflectors, interdigital transducers, and the combination in a complete resonator. The four variables are related to force, particle velocity, electric potential, and electric current. Results show that unconnected metal stripe reflectors on YZ lithium niobate have a phase angle of reflection which is approximately 180 deg different from that predicted by other models. Consequently, the correct spacings for complete resonators are accurately predicted. Reflectivity of reflectors, electrical input impedance, and acoustic fields of a complete resonator are given over frequency ranges of interest.