| 摘要 |
PURPOSE:To decrease the dispersion in reflecting characteristics and to make a titled device small-sized, by providing a reflector consistuted with a material in which the full reflection critical angle is <=45 deg., to a transmission path of surface acoustic waves on a piezoelectric substrate. CONSTITUTION:An input electrode 2 and an output electrode 4 are arranged on a piezoelectric substrate 3 and comb type converters 21 and 41 are connected respectively. An electric signal is given to an input electrode 2 from an input terminal 1, the conversion between the electric signal and the surface acoustic waves is made at the comb type converter 21, the surface acoustic waves propagate on the piezoelectric substrate 3 and are converted into an electric signal at the comb type converter 41 and outputted from an output terminal 5. On the path of surface acoustic waves, a reflector 7 constituted with a material in which sound velocity is different from that on the piezoelectric substrate and the full reflection critical angle is <=45 deg. is arranged so tht the reflecting end is a linear ridge end of 45 deg. with respect to the propagation direction of surface acoustic waves, and the surface acoustic waves of the incident angle of 45 deg. can fully be reflected. |
