SURFACE-ACOUSTIC-WAVE CHARACTERISTICS ON ZNO YZ.LINBO3 STRUCTURE AND THEIR APPLICATION TO ELASTIC CONVOLVER/

In an effort to improve the efficiency of an elastic convolver, we dis cussed Rays to increase the electromechanical coupling factor of the L iNbO3 (LN) substrate. We examined, both theoretically and experimental ly, the surface acoustic wave (SAW) characteristics of ZnO films forme d on the Y-+ . and -Y . planes of the YZ . LN substrates. As a result, it was clear that a larger electromechanical coupling factor, k(s), c an be obtained with a ZnO film on the +Y . plane than on the -Y . plan e of YZ . LN substrates. The maximum value of the coupling factor obta ined was 0.32, which was 2.04 times the square (k(s)(2)) of the value obtained without the ZnO film. BS applying the LN substrate with the Z nO film on its +Y . plane to the elastic convolver, we obtained a proc essing time of 7.6 mu s, a 3 dB bandwidth of 44 MHz and an efficiency of -58 dBm.