Calculation of band-pass filters using piezo-electric crystals in lattice structures

The critical frequencies in the transmitted and attenuated ranges are computed independently from the image attenuation constant and the image impedance respectively, these being chosen as acceptable approximations. Rumpelt's attenuation-gauge method is applied to give a solution in terms of single attenuation pole sections in tandem and Bode's theory used to reduce the system to a symmetrical lattice structure. Calculations are given for narrow and wide band-pass filters and response curves shown of actual models.