Velocity dispersion effect described in frames of quasi-static approximation for modeling of higher-harmonics filters

The quasi-static approximation is modified for the assumption that the SAW wave propagates with different wave-numbers within an electrode finger and within an inter-finger gap. In this case the evaluation formula for the SAW device frequency response at high harmonics substantially differs from the Fourier integral of the electrostatic charge distribution and is written in a form similar to the classic quasi static approach, but with modified both element and array factors. The method allows simulating the behavior of SAW resonators made on piezo-film, as well as SAW band pass filters made on lithium niobate at high harmonics.