The Effect of Diffraction on the Design of Acoustic Surface Wave Devices

A complete review of acoustic surface-wave dif- fraction on anisotropic substrates is presented. Full experi- mental verification of theory is provided. The limits of applicability of the parabolic velocity surface theory are quantitatively delineated. Universal diffraction loss design curves are given for all parabolic materials. A limitation in the use of the exact angular spectrum of waves theory occurs for materials having a power flow angle slope - I due to inaccu- rate knowledge of the velocity surface. Both YZ LiNbQ and 16.5 double rotated LiNb03 fall in this category. Approxi- mate diffraction loss design curves are given for YZ LiNb03. A complete tabular summary of all important material proper- ties affecting acoustic surface wave device design is included.