Sezawa SAW devices: Review of numerical-experimental studies and recent applications

Abstract

The technological field of surface acoustic wave (SAW) devices has progressed rapidly. The fundamental Rayleigh mode has been mainly used in SAW applications, while the outstanding properties accompanying its first higher order mode (called Sezawa mode) has stimulated numerous studies throughout the international research community over the last 50 years. Although some interest has been manifested toward it, the Sezawa mode has not yet been documented within a single paper covering the existing literature on the subject. The present review paper intends to fill this knowledge gap by gathering key information and synthesizing summaries from many papers that have dealt with this particular topic. The twofold objective consists of providing an up-to-date overview of this study area, and showing the relevance and advantages of utilizing the Sezawa mode in SAW devices, in order to encourage the researchers to expand the use of the Sezawa mode to other SAW applications. Moreover, this paper discusses the theoretical considerations concerning surface acoustic waves, the numerical and experimental studies devoted to the Sezawa mode, the survey of Sezawa mode applications made before 2000, its recent applications in SAW devices, the technical advices on the fabrication of such SAW devices, and the new research directions.