Phase detector circuit synthesizes own reference signal
Circuit with isolation amplifier connected to a frequency multiplier and synchronous phase detector synthesizes the phase reference signal from the phase modulated input signal.
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Results for “phase modulation”
Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.
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Mode-locked quieting of He-Ne and argon lasers.
LF noise suppression in He-Ne and Ar lasers by internal phase modulation resulting in mode coupling
Targ, R.↗
Response of a cascade connected limiter and phase detector to PM signals
Response of cascade connected limiter and phase detector to phase modulated signals
Chang, J. C.↗
The response of hard-limiting band pass limiters to PM signals
Output signal to noise ratio of bandpass limiter calculated for phase modulated signal
Chang, J. C.↗
Synthesis techniques for a class of SSB-AM-PM signals.
Subcarrier phase modulated single sideband sinusoidal carrier synthesis, discussing signal power ratios, signal efficiency, design sensitivity, etc
Painter, J. H.↗
Development and Implementation - DSIF Development
Antenna system instrumentation, phase modulator designs, control systems for transmitter and motor generator, and related DSIF developments
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Measurement of minor reactance changes with synchronized electronic oscillators
Circuitry for phase modulated synchronized electronic oscillators for measuring minor reactance changes during remote sensing
Dalins, I.↗
The radio emission from pulsar MP 0031-07
Phase modulation drift of radio emission from pulsar MP 0031-07
Huguenin, G. R.↗
Technique for measuring laser beam propagation direction fluctuations
Measuring technique for short term laser beam propagation direction fluctuations, discussing atmospheric turbulence effect on initial modulation phase distribution
Kuriger, W. L.↗
Simulation of 10.6 micron laser space- communications system
Breadboard simulation model of laser space communications system consisting of carbon dioxide laser, transmitter telescope, GaAs phase modulator and attenuator
Peruso, C. J.↗
Mode locking of the CW dye laser
CW dye laser mode locking with lithium niobate phase modulator, observing 500 psec pulse generation
Kuizenga, D. J.↗
Sensitive holographic detection of small aerodynamic perturbations
Phase modulations enhance the sensitivity of holographic techniques for detecting disturbances which are caused by variations in gas density of the order of 1/10 wavelength or less. In the readout, subject perturbations show up as brightenings on a dark background.
Heflinger, L. O.↗
Direct observation of the orientational Kerr effect in the self-focusing of picosecond pulses.
Direct measurements of the relaxation time of the birefringence within the self-focusing region of mode-locked laser pulses in several anisotropic liquids establish the importance of the orientational Kerr effect in the picosecond time regime. This result leads to some speculation as to the origin of the high degree of symmetry in the phase-modulated filament spectra observed with picosecond pulses.
Reintjes, J.↗
A receiver design for the ATS-F radio beacon experiment.
The basic design of the overall receiving system is determined by the received power density from the satellite and the desired compromise between ground antenna aperture, system response times, and measurement signal-to-noise ratio. The measurement of Faraday rotation is discussed together with the measurement of modulation phase, aspects of system calibration, and overall system concepts.
Grubb, R. N.↗
Modeling and prediction of ionospheric scintillation
Scintillation modeling performed thus far is based on the theory of diffraction by a weakly modulating phase screen developed by Briggs and Parkin (1963). Shortcomings of the existing empirical model for the scintillation index are discussed together with questions of channel modeling, giving attention to the needs of the communication engineers. It is pointed out that much improved scintillation index models may be available in a matter of a year or so.
Fremouw, E. J.↗
A passive submicrosecond time dissemination system
A submicrosecond time dissemination system was developed. The system is composed of an experimental transit improvement satellite (TRIAD), TRANET Satellite Tracking System, and special satellite signal receivers each tied to separate cesium clocks. The 400 MHz signal from the satellite is phase modulated plus or minus 45 deg by a pseudo-random noise (PRN) digital code with a bit rate of 5/3 MHz. Evaluation of this system has shown that satellite oscillator frequency instabilities are the major source of error. Experiments indicate that Global time transfers can be made with errors less than 100 nanoseconds.
Taylor, R. J.↗
The TWERLE balloon-to-satellite data transmitting system
This paper describes the balloon instrumentation system which provides the one-way link for data gathering and navigation in the Tropical Wind, Energy conversion and Reference Level Experiment (TWERLE). In this experiment, 400 instrumented constant-level balloons will be launched at the southern hemisphere during 1975. The Random Access Measurement System (RAMS) on board the Nimbus-F satellite, will comprise the receiving end of the link. The data encoder, stable oscillator, transmitter and antenna are described, as well as two supporting components, the power source and the magnetic cutdown. These six items weigh 850 g. The oscillator-transmitter consume 1.9 W dc power to provide 0.6 W phase modulated RF power.
Levanon, N.↗
College curriculum-sharing via CTS
Domestic communication satellites and video compression techniques will increase communication channel capacity and reduce cost of video transmission. NASA Ames Research Center, Stanford University and Carleton University are participants in an experiment to develop, demonstrate, and evaluate college course sharing techniques via satellite using video compression. The universities will exchange televised seminar and lecture courses via CTS. The experiment features real-time video compression with channel coding and quadra-phase modulation for reducing transmission bandwidth and power requirements. Evaluation plans and preliminary results of Carleton surveys on student attitudes to televised teaching are presented. Policy implications for the U.S. and Canada are outlined.
Hudson, H. E.↗