CONSISTENT GENERALIZATION OF COM EQUATIONS TO 3-DIMENSIONAL STRUCTURES AND THE THEORY OF THE SAW TRANSVERSELY COUPLED WAVE-GUIDE RESONATOR FILTER

An analytical theory for calculating the response of a transversely co upled waveguide resonator filter (TCF) is derived consistently from th e analytical model for the description of two-dimensional structures. The COM equations for slowly varying amplitudes of the SAW electric po tential as functions of the longitudinal coordinate are derived, The c oefficients of these equations such as reflectivity, phase delay and t ransduction coefficient are calculated for each mode. The theory conne cts the material and geometrical parameters of the structure with the characteristics of the TCF, The frequency dependence of the admittance matrix and insertion loss for one and two cascaded filters are consid ered. The splitting of the resonance peaks due to cascading is investi gated. Good agreement between theoretical and experimental results is found.