Abstract: Signal processing apparatus having the capability to perform simultaneous space-time processing of sonar, radar and similar time-varying signals, and to effect the Fourier transform of multiple time-varying signals through electro-optical photoelastic means, photoconductive means, or photoemissive means.

Abstract: The present invention relates to refractive stigmatic systems designed to deflect or focus elastic surface waves which can propagate at the surface of a substrate. The object of the invention is a lens or prism comprising an array of elementary refractive zones formed by deposition or ion implantation and intended to produce uniform attenuation of refracted vibrational radiation.

Abstract: A phase modulation system is described in which the phase of a carrier wave can assume one of a number of permitted values in each symbol period and wherein transitions between the permitted values occur at transition periods between symbol periods. Difficulties associated with phase transitions are reduced or overcome by storing or generating the transitions with a number of cycles of the carrier wave of the appropriate phase(s) on either side thereof, a wave train being built up by merging the corresponding oscillations of the same phase which succeed and preceed respectively two adjacent transitions.

Abstract: A device for producing a chorus effect in an electronic musical instrument. An electronic delay circuit and a non-modulating amplifier means are coupled in parallel and the outputs are mixed in a mixing amplifier. A carrier oscillator is coupled to the delay circuit for controlling the time delay of the delay circuit according to the frequency of its output, and normally oscillates at a relatively high frequency in the range of 80-100 KHz. A modulation signal generator is coupled to the carrier oscillator for frequency modulating the carrier oscillator toward lower oscillating frequencies, and a control signal generator is coupled between the input to the delay circuit and the modulation signal generator for detecting the musical tone signal input to the delay circuit and producing a control signal only when a musical tone signal input is detected.

Abstract: An acoustic surface wave interdigital transducer comprises a main and auxiliary rows of electrodes arranged on a piezoelectric substrate. The main row of electrodes comprises a first group of electrodes galvanically connected to a first contact area and a second group of electrodes parallel to the electrodes of the first group and disposed therebetween so that there are formed overlapping portions having the same length. The auxiliary row of electrodes comprises a third group of electrodes galvanically coupled to the second contact area and a fourth group of electrodes parallel to the electrodes of the third group connected directly to the corresponding electrodes of the second group of the main row and disposed between the electrodes of the third group so as to form overlapping portions of electrodes of both groups, said portions having a variable length. The electrodes of the second group of the main row are connected to the second contact area through capacitances.

Abstract: A cascade charge coupled delay circuit including a plurality of serial delay line sections formed on a single semiconducter wafer, said delay line sections being directly coupled to one another through the wafer and means for independently clocking each section of said lines.

Abstract: A microminiature electrical delay line utilizes an m-derived filter formed by depositing a film of permalloy or other high permeability metal on a quartz or other dielectric substrate, then depositing a layer of quartz or other dielectric over the permalloy film, after which a plurality of microminiature thin film inductance coils are deposited on the dielectric layer and joined together electrically in series, a top layer of quartz or other dielectric then is deposited over the interconnected coils and a strip of permalloy or other high permeability metal is deposited over the top dielectric layer to extend across the coils, a gap being provided in the strip of permalloy at the central axis of each coil.

Abstract: An acoustic periodic structure for slow wave propagation and filtering having a corrugated surface with traction-free boundaries which can support a horizontally polarized shear surface wave that travels much slower than the bulk shear wave velocity and that exhibits an upper cut-off frequency. Electrodes are located on the tops of the teeth forming the corrugated surface and alternate electrodes are excited out of phase, the distribution of the excitation voltage phases determining the particular mode of resonance.