Bismuth Germanium Oxide (BGO) Surface Acoustic Wave (SAW) Convolver Device.
Abstract
This report describes the design and evaluation of strip-coupled convolvers (SCCs) with large time-bandwidth products. A multichannel concept was developed for this project in order to reduce the deleterious effects and fabrication complexities due to extensive metallization in the acoustic propagation paths (an inevitable consequence of SCCs with long interaction times). With this approach the interaction region is divided among N separate convolver channels, each covering 1/Nth of the total interaction region, and the respective outputs are summed. Using this technique, SCCs with equivalent time-bandwidth products in excess of 1000 have been demonstrated. Further, with the best device, the nonlinear coupling coefficient M was found to be of the theoretical order of magnitude, and to have internal conversion efficiencies an order of magnitude better than corresponding air-gap convolvers (AGCs). The results of these investigations led to the conclusion that, with optimum efficiency in the input and output circuits, large time-bandwidth (2000-5000) SCCs, with efficiencies up to 20 dB greater than currently available modes, are a real possibility. These higher efficiencies, together with relatively simple fabrication procedures, make the multichannel SCC an attractive device for further development. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Feb 16, 1979
- Accession Number
- ADA065303
Entities
People
- L. R. Adkins