Patent · US Expired

Surface acoustic wave device

US4868444A · kind A · utility

11Cited by
3References
8Claims
0Family size

Assignee

Inventors

Key dates

Filing dateOct 18, 1988
Grant dateSep 19, 1989
Priority date
Expiry dateOct 18, 2008

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH03H9/02574
  • WIPO fieldBasic communication processes
  • WIPO sectorElectrical engineering

Abstract

A surface acoustic wave device having a single crystal aluminum nitride film wherein when the direction of propagation of the surface acoustic wave is expressed by (.lambda.,.mu.,.theta.) according to the Euler angle notation, .theta. is set to 90 degrees, .lambda. to a desired angle, and .theta. to an angle in the range of 30 to 150 degrees. In a surface acoustic wave device having a c-axis-oriented aluminum nitride film, the direction of c-axis orientation of the piezoelectric film is inclined within a plane containing the direction of propagation of the surface acoustic wave and perpendicular to the surface of the piezoelectric film at an angle in the range of about .+-.30 degrees to about .+-.150 degrees with respect to a normal to the piezoelectric film. The devices are 1.122% in maximum coupling coefficient.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.