Trw Limited

Other

Marshall Y Huang

Robert Bruce Stokes

Kuo-Hsiung Yen

Robert A Frosch

Mark Kintis

Barry Ross Allen

Gregory A Shreve

Reynold S Kagiwada

Albert J Grote

James R Barnes

Sidney B Franklin

Arthur Garabedian

Curtis S Hoffman

Robert E Kasody

Kuo-Hsuing Yen

Robert B Marcum

A voice-activated microphone and transceiver system includes an interrogator unit for transmitting a signal, receiving a modulated signal, and demodulating the modulated signal such that the difference between the transmitted signal and the modulated signal correspond to a unique sound wave signal. An acoustically driven microphone unit is also included for receiving the signal from the interrogator unit, modulating the signal with the sound wave signal, wherein the sound wave signal contains instructions for controlling an electronic device, and transmitting the modulated signal back to the interrogator unit for analysis by a signal processor.

Passive voice-activated microphone and transceiver system

A variable delay line detector ( )includes a power splitter ( ), a mixer ( ) and a variable delay line ( ). Various devices are suitable for the variable delay line ( ), such as a non-linear transmission line (NLTL). By providing a variable delay line, the variable delay line detector ( ) is adapted to be programmed in real time thus making it suitable in applications where the phase and or frequency of the input signal varies. As such, the variable delay line detector ( ) may be used in applications heretofore unknown, such &a an inexpensive demodulator in a frequency hopped spread spectrum system.

Variable delay line detector

Apparatus, and a method for its use, for linearly phase-modulating a microwave signal with only minimal accompanying amplitude modulation. An incoming signal is divided into two components, one of which is shifted by ninety degrees from the other, plus or minus a small offset phase angle selected to minimize amplitude variations in an output signal. The component with the offset phase angle is amplitude modulated, then recombined with the other component to provide the desired phase-modulated output signal. When the offset phase angle and the nominal amplitude of the amplitude-modulated component are appropriately selected, phase modulation of the output signal is substantially linearly related to the amplitude modulation of the offset input signal, and amplitude modulation of the output signal is minimized.

Microwave phase modulator having a quadrature path with phase offset

A surface acoustic wave (SAW) device for converting multiple parallel signals to a smaller number of serial signals. The device includes a piezoelectric substrate and a surface acoustic wave (SAW) input transducer for propagating periodic surface acoustic waves across the substrate. The parallel signals are input to the device through an array of acoustic charge transport (ACT) input transducers, which convert the signals into packets of electrical charge that are transported across the device with the surface acoustic waves generated at the SAW input transducer. An ACT output transducer converts the charge packets back into electrical signals, but in serial rather than parallel form. The converter of the invention can be usefully combined with a SAW channelizer or spectrum analyzer, to provide serial outputs from the analyzer.

Parallel-to-serial signal processor using surface acoustic waves

A surface acoustic wave (SAW) device, and corresponding method, for expanding or contracting the time scale of an input signal that varies in time but is limited to a predetermined time interval. One embodiment of the invention achieves time expansion or compression by means of two Fourier transformations providing different chirp rates, and implemented in a form that includes only five SAW dispersive delay lines. In the illustrative version of this embodiment, three of the dispersive delay lines are used in conjunction with multipliers or mixers, and two are used as convolvers. Another embodiment of the invention uses only three SAW dispersive delay lines, two in conjunction with multipliers and one located between the multipliers to effect the desired time-scale change. A third embodiment of the invention employs a SAW tapped delay line and an associated set of gates to select successive data bit signals from successive output taps in the delay line. A SAW fill-in filter is used to fill in inter-bit gaps resulting from the use of the tapped delay line.

Surface acoustic wave device for data rate reduction

Circuitry and methods are presented for detecting the presence of a spectrally distributed signal having a known distribution, e.g. spread spectrum, in a strong noise environment. The signal is split into two channels, each filtering a predetermined frequency band within the given spectrum. The channels are tuned and balanced so that they pass differential amounts of signal energy that may be present but provide equalized noise outputs. The channels are alternately coupled to the input of an energy detector which provides a DC component responsive to the difference in the signal levels of interest, while effectively cancelling noise energy components in each channel. In the spread spectrum example the frequency bands are typically selected to the maximum and a null location in a ##EQU1## distribution.

Signal presence detector and method

A low distortion phase compensated wideband amplifier system includes a low cost, power efficient Class C amplifier positioned along a primary signal path and a feedback loop coupled to provide negative feedback of distortion signal components in the amplified output signal. The negative feedback significantly reduces noise components including intermodulation noise while variable delay phase compensation permits a greater signal to noise ratio over a broader band of frequencies at the system output.

Wideband, phase compensated amplifier with negative feedback of

A self-calibrating threshold detector for use with receivers adapted to receive an incoming transmitted signal carrying a prescribed code. The detector comprises a single demodulating channel which includes a mixer having one input receiving the incoming signal and another input receiving a local replica code. During a short time interval, an incorrect local code is applied to the mixer to incorrectly demodulate said incoming signal and to provide a reference level that calibrates the noise propagating through the channel. A sample-and-hold circuit is coupled to the channel for storing a sample of the reference level. During a relatively long time interval, the correct replica code provides an output level which ranges between the reference level and a maximum level that represents incoming signal presence and synchronism with the replica code. A summer subtracts the stored sample reference from said output level to provide a resultant difference signal indicative of the acquisition of the expected signal.

Self-calibrating threshold detector

A surface acoustic wave filter device having an input transducer and an output transducer, in which triple transit effects are minimized by the addition of a second output transducer spaced from the input transducer, preferably by a distance three times the spacing between the normal input and output transducers, to duplicate the triple transit path length. A triple transit signal is thereby simulated at the second output transducer, is adjusted in amplitude and phase, and is applied to a summing circuit in which the simulated triple transit signal is subtracted from a signal derived from the original output transducer, to effectively cancel the triple transit component.

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Rancho Palos Verdes, CA, United States of America

Marshall Y Huang