Consistent generalization of COM equations to three-dimensionalstructures and the theory of the SAW transversely coupled waveguideresonator filter

摘要

An analytical theory for calculating the response of antransversely coupled waveguide resonator filter (TCF) is derivednconsistently from the analytical model for the description ofntwo-dimensional structures. The COM equations for slowly varyingnamplitudes of the SAW electric potential as functions of thenlongitudinal coordinate are derived. The coefficients of these equationsnsuch as reflectivity, phase delay and transduction coefficient arencalculated for each mode. The theory connects the material andngeometrical parameters of the structure with the characteristics of thenTCF. The frequency dependence of the admittance matrix and insertionnloss for one and two cascaded filters are considered. The splitting ofnthe resonance peaks due to cascading is investigated. Good agreementnbetween theoretical and experimental results is found