Engineering topics
Publications and source records attributed to Winkelstein, R. A..
Sideband-aided receiver arrays (SARA's) offer way of extracting greater energy per bit in radio data signals. "Slave" receivers obtain modulation information from "master" receiver. Developed for reception of telemetry from vehicles in deep space, SARA concept applicable to commercial data-signal reception whenever two or more antennas are combined.
The invention provides a means whereby the baseband output signals of all but one of the receivers associated with each of the antennas are summed and used as a correlation reference for the baseband signal not contained in the summed signal, thereby providing a plurality of correlation or alignment loops, each having an output signal related to the phase difference between its input baseband signal and the summed signal. The invention further provides a means for subtracting an output or error signal generated in one of the correlation loops whose baseband signal has a predetermined phase delay from all the other alignment loops, thereby avoiding interaction and reflection effects in the signal combiner. A variable phase delay means for each of the other baseband signals is controlled by its corresponding correlation loop.
Absolute value of signal power in weak radio signals is determined by computer-aided measurements. Equipment operates by averaging received signal over several-minute period and comparing average value with noise level of receiver previously calibrated.
Software development methods have been investigated and two test bed projects have been chosen to evaluate application techniques of the 8080A and support microcircuits which will satisfy DSN requirements. Final recommendations will reflect successful JPL applications experience.
Quadrature correlation for automatic signal phasing and variable delay is used to combine signals for improved signal-to-noise ratio.
Extremely-accurate and low-phase-noise frequency generator varies oscillator frequency as predetermined function of time. System could be used: (a) to automatically vary transmission frequencies in accordance with seasonal and diurnal changes in ionospheric conditions, (b) as automatic tuner for heterodyne receivers, or (c) as control element for phase-locked telemetry receivers.
A controlled oscillator system is presented for providing an output with a frequency which changes with respect to time and with a phase which is within established phase error limits. The system includes a frequency synthesizer with a symmetrical search oscillator, capable of tuning the output with a range of + or - 100 Hz about any fixed frequency to which the synthesizer is set. For a tuning range of 200 Hz (+ or - 100 Hz) an expanded search oscillator output of a frequency range of 4 MHz (from 1 MHz to 5 MHz) is provided. A counter counts continuously the expanded output cycles and at each of fixed sampling intervals, for every 0.1 second, the count or number accumulated in the counter is read out. The sample number is compared with a theoretical number which should be present in the counter at the particular sampling instant for proper synthesizer's output frequency and phase.
Noninterruptable digital counter circuit design with display device for pulse frequency modulation
Circuit controls a voltage controlled oscillator from computer output binary data representing a rate at which the oscillator is to change. It operates with low level output devices such as integrated circuit registers and devices with somewhat variable output levels.
Radio communication system instrumentation for Mariner IV space probe, and received spectrograms