Networks for Crossed-Field and In-Line Excitation of Bulk and Surface Acoustic Waves,
ARMY ELECTRONICS TECHNOLOGY AND DEVICES LAB FORT MONMOUTH N J
Pagination or Media Count:
From a unified point of view, equivalent network descriptions of piezoelectrically driven devices of both surface and bulk wave kinds were considered. Particular attention is given to the mechanism of excitation, and to the demonstration that the networks are capable of a comprehensive and detailed interpretation in which their various components are so arranged that they accurately depict the underlying physics of the devices they characterize. Four situations are considered. The crossed-field laterally excited and in-line thickness-excited quasistatic circuits of crystal plates excited in bulk thickness modes are first interpreted in terms of their exact geometrical correspondences with the physical features of the plate resonators, particularly that of the piezotransduction mechanism. Next, the case of surface waves produced by interdigital arrays is discussed. The quasistatic equivalent netowk is given on an analog basis, and it is shown how the network corresponds exactly to the delta-function model. The network may be used for any surface wave mode by suitably defining appropriate mode functions associated with the transmission lines supporting the surface mode in question. The third case considered is that of the circuit representation of bulk acoustic wave production in a piezoelectric rod by an applied microwave cavity field. It is shown how this category may be treated on the basis of a limiting form of the first case. Case four consists of relaxing the quasistatic constraint for crystal plates subjected to crossed-field excitation.
- Line, Surface and Bulk Acoustic Wave Devices