On the theory of linear surface acoustic wave devices

Stationary distribution of the efficient wave sources excited by interdigital transducers (IDT) of arbitrary configuration has been derived on the basis of reciprocity of the generation and reception of surface acoustic waves (SAW) in piezoelectrics. It was shown that these sources represent a linear combination of two stationary distributions on the surface S between the piezoelectric and IDT: the distribution of the normal component of SAW flux density formed in the mode of SAW reception by the short-circuit IDT and the field distribution of the SAW electric potential at the same surface S but in the absence of piezoelectric. The Y-parameter matrix of the device was obtained as an electric M×2-terminal network containing M IDT. It was shown that the SAW transfer admittances and SAW radiation admittances contained additional frequency-dependent multipliers. The characteristics take into account the smoothed diffraction, spatial dispersion in IDT, reflections from IDT, and electric loads of the device