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

TLDR

Both YZ LiNbQ and 16.5 double‑rotated LiNbO₃ fall into the category of materials with a power‑flow‑angle‑slope‑−I. The study identifies a limitation of the exact angular‑spectrum‑of‑waves theory for such materials and supplies a comprehensive tabular summary of key material properties for acoustic surface‑wave device design. The authors provide a comprehensive review of acoustic surface‑wave diffraction on anisotropic substrates, experimentally verify the theory, quantitatively delineate the limits of parabolic velocity surface theory, and present universal diffraction‑loss design curves for all parabolic materials, with approximate curves for YZ LiNbO₃.

Abstract

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.