Motorola Corporation

Texas Instruments Corporation

Donald C Malocha

Frederick M Fliegel

Frederick Y Cho

David Penunuri

Robert S Wagers

Jeffrey H Goll

Frederick Y Ch

An ACT (acoustic charge transport) filter comprises a plurality of SAW (surface acoustic wave) transducers and an interleaved filter bank coupled on either transversal side of the SAW transducer. Each interleaved filter bank comprises two filters, and the electrodes of the two filters are interleaved. Isolation between the interleaved electrodes is supplied by a meadering ground. The electrodes are apodized to facilitate weighted sampling of the delayed signal. Multiple frequency characteristics may be extracted from a single ACT filter by cascading the SAW transducer/interleaved filter bank combinations. Weighted sampling of the delayed signal may also be accomplished through weighted withdrawal of the ACT filter.

Multiple nearest neighbor filter bank

An acoustic charge transport device (ACT) alters the intersection of an associated surface acoustic wave (SAW) electric potential with the static depletion potential and the input contact potential to correct the timing variations inherent in conventional ACT devices. The ACT device incorporates a pair of correcting electrodes secured to the ACT channel on either side of an input electrode. The electrodes vary the depth of the electric potential of the SAW which ensures sampling of the input signals at consistent times.

Time delay modulation and correction device

A SAW transducer eliminates mechanical energy reflections by using one-quarter wavelength electrodes spaced at predetermined intervals. Dummy electrodes are shifted one-quarter wavelength to cancel energy reflections in the active electrodes. A pair of dummy electrodes is required for each active set of electrodes (the active set comprises one positive and two negative electrodes).

SAW reflectionless quarter-wavelength transducers

A structure for compressing an acoustic surface wave into a symmetric higher energy density output surface acoustic wave. Conductive strips are placed in parallel upon a piezoelectric surface. When a symmetric input is generated at one side of the multistrip coupler, the energy of the input wave is compressed into the center channel and is presented at the output in a single moded symmetric form.

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Longwood, FL, United States of America

Donald C Malocha