Accession Number : ADA018440
Title : Integrated Surface Acoustic Wave Convolver/Amplifier.
Descriptive Note : Final technical rept. 6 May 74-6 Jun 75,
Corporate Author : SPERRY RESEARCH CENTER SUDBURY MASS
Personal Author(s) : Solie,L. P.
Report Date : NOV 1975
Pagination or Media Count : 45
Abstract : The work on this contract involves the development of a highly efficient surface wave convolver by means of bidirectional surface wave amplification of the counter-traveling surface waves to compensate for the attenuation they would otherwise incur. The surface wave propagates along a piezoelectric substrate (YZ LiNbO3) with a semiconducting film overlay (CdSe). The same interdigital electrodes which detect the convolution signal are used to apply the dc bias fields on the semiconducting film for the surface wave amplification. As a result, the surface wave convolution is considerably enhanced and the signal duration may be much longer than is possible by other techniques. The convolution efficiency of -10 dBm is 20 dB to 80 dB higher than is possible by other types of surface wave convolvers. Perhaps the most significant result of the work done under this contract was the discovery of a new mode of operation. This is a degenerate mode whose existence depends upon the bidirectional amplification of this device. It should be noted that this degenerate mode is detected by an interdigital center structure and it is even more efficient than the nondegenerate mode. The interdigital electrodes may be skewed relative to the input transducers so reflections from the electrodes no longer limit the performance of the device in any way.
Descriptors : *Surface waves, *Acoustic waves, *Signal processing, Amplification, Traveling waves, Amplifiers, Integrated systems, Piezoelectric materials, Substrates, Semiconducting films, Coding
Subject Categories : Line, Surface and Bulk Acoustic Wave Devices
Distribution Statement : APPROVED FOR PUBLIC RELEASE