Abstract: A convolver includes first and second buried channels, with each of the channels comprised of a piezoelectric semiconductor. The input of one channel is associated with the output of the other channel. An acoustic transducer is positioned adjacent each input for generating an acoustic wave which propagates through the associated channels and thereby transports charge from the input to the output thereof. A non-destructive sensing array overlies the channels and samples the charge transported thereunder. The array includes an assembly for summing the sampled charge and for generating a product. An electrode is operably associated with the summing assembly for integrating the products and generating a convolution signal.

Abstract: A complementary acoustic charge transport circuit element comprises first and second buried channels. Each of the channels is comprised of a piezoelectric semiconductor and each channel has a source through which charge is injected and a drain through which charge is extracted. A transducer propagates an acoustic wave through each channel and the propagated waves transport the charge between the sources and the drains. A source and/or a drain of one channel is connected in parallel with the corresponding souce and/or drain of the other channel. The waves are complementary at the interconnected ones of the sources and/or the drains.

Abstract: Method and apparatus for adaptive filtering a first signal to produce a second signal that approximates a desired signal including an acoustic charge transport type programmable transversal filter (PTF) having a number of taps where each tap corresponds to an associated delayed first signal and each tap having means for providing a variable tap weight to modify the filter response. The first signal is coupled to the PTF and the output of the PTF produces the second signal. A summer compares the output of the PTF and the desired signal to produce an error signal. A programmable delay line has time delays programmable to integer multiples of the PTF tap spacing to provide a delayed version of the first signal, and a multiplier multiplies the error signal and the delayed input of the programmable delay line to produce a gradient signal.

Abstract: A transversal filter comprises an acoustic charge transport device comprising an input contact for introducing a signal into a buried channel through which the signal is transported by a high frequency acoustic wave and a plurality of non-destructive sense electrodes overlying the channel for successively sampling the signal. A memory device is provided for storing a plurality of tap weight signals, with each tap weight signal for being associated with one of the electrodes. A multiplier system is operably connected with each of the electrodes and with the storage device for generating the product of the signal sampled at each electrode and the associated tap weight signal. A summer is operably associated with the multiplier for summing the products and thereby generating an output signal.

Abstract: A delay device comprises a semi-conductor chip having acoustic charge transport channel disposed therein; a contact operably connected to and disposed at one end of the channel for injecting an electronic signal into the channel; a transducer for generating a single frequency, large amplitude acoustic surface wave through the channel for thereby transporting the electronic signal through the channel; a plurality of electrodes operably associated with the channel and disposed along the propagation path of the surface acoustic wave for non-destructively sensing the electronic signal; switches monolithically disposed on the chip and operably connected to the electrodes for preselecting any one of the electrodes, thereby extracting a delayed replica of the signal from the channel; and an output circuit for processing the extracted signal for generating an output.

Abstract: The disclosure is directed to a method and a device for delaying an electrical signal, the method and device being useable in various signal processing applications. A buried channel is formed by disposing a portion of a layer of piezoelectric semiconductor material between confining layers. A surface acoustic wave is established in the piezoelectric semiconductor material. Majority carriers are depleted from the channel, and an electrical signal is injected into the channel. A delayed version of the electrical signal, which had been carried along by the surface acoustic wave, can then be extracted from the channel.

Abstract: A signal processor for filtering unwanted narrowband noise from received wideband electrical signals also containing desired wideband noise is described. The signal processor includes means for partitioning the wideband received signal into a plurality of narrowband, noise-containing signals and for producing a plurality of narrowband output signals. The signal processor further includes means for monitoring each of the narrowband output signals and for reducing the voltage of any narrowband output signal when that signal exceeds a predetermined level. In the preferred embodiment, the monitoring means of the signal processor includes a plurality of voltage-regulating networks, wherein each network receives as a network input signal, a single one of said narrowband output signals into a detector and integrator network to produce an output command signal only when the voltage across a channel exceeds a predetermined level.