Extraction of Derivatives from Data Stored in an Acoustic Memory

Abstract

Simple means are proposed and analyzed for the extraction of outputs proportional to the derivatives of data samples stored in the form of surface acoustic waves propagating on a piezoelectric crystal. Extraction of the derivatives is done by simply- shaped electrode transducers. A simple principle is presented to predict the derivative outputs for various surface acoustic waveforms. Computer analysis of the devices yields time responses revealing the differences between adjacent data elements with resolutions as high as 30 dB. Comparison with experimental results is also made.