Doubly Rotated Cut SAW Devices.
Abstract
The objective of this program is the exploratory development of doubly rotated cuts of quartz possessing superior Surface Acoustic Wave (SAW) properties for applications involving environmentally hardened devices. The key properties examined and optimized both theoretically and experimentally are: first, second and third order Temperature Coefficients of Delay (TCD), piezoelectric coupling factor, power flow angle, Bulk Acoustic Wave (BAW) inverse velocity surfaces, degeneracies and leaky waves, and sensitivities of the above quantities to misorientations and manufacturing tolerances. The program consists of two major task areas comprising an interactive numerical/experimental approach. Task I involves the numerical computation of the key SAW properties for doubly rotated quartz substrates for the purpose of locating promising angular ranges with properties superior to the singly rotated cuts now in existence. More detailed calculations follow to refine the angular coordinates in order to specify cuts for experimental verification in Task II. In Task II, sets of substrates with promising orientations identified in Task I were prepared and SAW device patterns were fabricated for evaluation of the key SAW properties. The experimental results of this task were correlated with the theoretical predictions and an iterative process developed for refinement of both theoretical and experimental parameters. As the program proceeded, working SAW device models were delivered as a demonstration of progress and an indication of the future potential of the doubly rotated cuts. This report contains the second iteration of the two major tasks mentioned above.
Document Details
- Document Type
- Technical Report
- Publication Date
- Aug 01, 1981
- Accession Number
- ADA103728
Entities
People
- Dylan F. Williams
- F. Y. Cho
Organizations
- Motorola Mobility