Abstract: A device for sample modulating electronic information signals, which includes a pulse position modulating circuit having a first input coupled to receive information signals, a second input coupled to simultaneously receive uniformly spaced sampling signals, and an output for generating thereon in response to each sampling signal an electronic output impulse at a time instant indicating the amplitude of the simultaneously received information signals. Also included is an acoustic surface wave device having an impulse response of predetermined shape and finite length. The surface wave device has an input coupled to receive the impulses from the pulse position modulating circuit for generating in response thereto output signals proportional to the convolution of the impulses with the impulse response. Accordingly, these output signals also are of predetermined shape and finite length, and thus have a highly controllable frequency spectrum.

Abstract: Disclosed is a frequency converting filter comprised of a charge transfer device transversal filter and a non-sampling filter. The transversal filter has an output lead coupled to an input of the non-sampling filter, and has frequency passbands of width .DELTA.f centered at the fixed frequencies nf.sub.s .+-.f.sub.o. The non-sampling filter has a single passband. The single passband has a width of less than f.sub.s -f.sub.o -.DELTA.f/2 and it is centered to include only a selected one of the passbands of the transversal filter.

Abstract: A surface acoustic wave sensor system in which a predetermined level of coupling between two surface acoustic wave arrays is intentionally provided in order to couple radio frequency energy from one into the other and thereby, in cooperative effect with attendant oscillator circuits and a filter, results in the development of a difference frequency which is a function of the sensed condition.

Abstract: A system and method of moving near-surface water to a deep water aquifer at a high rate of transfer and with no external energy sources, and which additionally generates excess energy available for other uses. The system comprises at least one deep well into the deep aquifer and one or more shallow wells into a near-surface water table aquifer having siphon pipes from the shallow wells to the deep well. Siphon action is initiated resulting in a continuing flow of water from the shallow wells to the deep well. A water-driven turbine is disposed in the deep well above its tail water level and below the lower end of the siphon tubes. The water flow operates the turbine and the turbine shaft drives an external vacuum pump. Each shallow well has a closed top plate, and suction from the vacuum pump is applied through the top plate, holding the water level above its normal point increasing the draw down.

Abstract: A device for sample modulating electronic information signals which includes mixing circuitry having a first input coupled to receive information signals, a second input for receiving electrical sampling signals, and an output for generating thereon electrical output signals proportional to the product of the information signals and the sampling signals. Also included is an acoustic surface wave device having an impulse response of predetermined shape and finite length. The surface wave device has an output coupled to the second input of the mixing circuit for generating thereon the sampling signals. These signals are proportional to the finite impulse response of predetermined shape, and accordingly have a highly controllable frequency spectrum.