FOUR BASIC FUNCTIONS AND GENERALIZED ELEMENT FACTORS CONSIDERING SAW VELOCITY DISPERSION EFFECT

摘要

A general approach for the description of the electrostatic field in an infinite regular electrode grating is presented. The general approach leads to four basic functions: a potential-basis, a voltage-basis, a dipolebasis and a charge-basis. These four basic functions are four degrees of freedom to approximate an electrostatic field for IDT of different structures. On the other hand, the usage of these four basic functions in the synthesis problem leads to four types of the IDT topology implementation. Generalized frequency element factors are written for the assumption the SAW waves propagate with different wave numbers within an electrode and within an interelectrode gap. This generalization explains the SAW spectrum behavior for high harmonics and especially for the SAW devices made up on piezo-film.