Showing papers on "Dynamic range published in 1975"
TL;DR: In this paper, the effects of laser radar data acquisition systems on photomultipliers were studied in the analog mode and the photon counting mode, along with single photoelectron pulse shape and afterpulsing.
Abstract: Laser radar data acquisition systems have been utilized in conjunction with a light emitting diode to evaluate photomultipliers for laser radar use. Light pulses with an exponential decay rate of approximately one decade per sixty microseconds, as well as other pulse shapes, were used to drive the tubes. Properties studied in the analog mode include nonlinearity at high output currents, transient behavior upon gating, gate holdoff, dynamic range limitations because of light-induced noise, and the effect of dynode gating on tubes without a focus grid. Some of these properties were also studied in the photon counting mode, along with single photoelectron pulse shape and afterpulsing. Tubes studied were the RCA 7265, the RCA 8852, and the RCA C1034. A brief description of the laser radar technique of atmospheric measurements is included.
32 citations
01 Feb 1975
TL;DR: In this paper, a dual-gate GaAs MESFET with maximum gain of 18 dB at 10 GHz and minimum noise figure of 4 dB with 12 dB associated gain was described.
Abstract: A dual-gate GaAs MESFET with maximum gain of 18 dB at 10 GHz and minimum noise figure of 4 dB with 12 dB associated gain will be described. Variation of second gate potential has been found to yield gain modulation with a 44 dB dynamic range and 70 ps risetime.
22 citations
01 Jan 1975
14 citations
TL;DR: An A-D and D-A converter system with exceptionally wide dynamic range and low distortion is discussed and rate-limiting during the transition from hold to track is discussed.
Abstract: An A-D and D-A converter system with exceptionally wide dynamic range and low distortion is discussed. The system utilizes 12-bit floating-point approximation at conversion instead of true 16-bit conversion. A deglitching track and hold is illustrated which avoids heterodyning between signal components and the sample clock. Rate-limiting during the transition from hold to track is discussed.
13 citations
Patent•
05 Sep 1975TL;DR: In this paper, the analog sigs are converted into frequency modulated light amplitudes which are transmitted by means of an inexpensive fiber optic bundle, and the transmitted modulated information is demodulated at the receiving end to obtain an exact replica of the input signals.
Abstract: A system for transmitting low level analog signals wherein the analog sigs are converted into frequency modulated light amplitudes which are transmitted by means of an inexpensive fiber optic bundle, and the transmitted modulated light is demodulated at the receiving end to obtain an exact replica of the input signals. The system enables one to maintain a large amplitude dynamic range using an inexpensive photo-transistor.
13 citations
TL;DR: A rule of thumb avoiding a computer program and an example are given, which will be used to maximize the dynamic range and the noise distance of the filters.
Abstract: RC-active filters are usually realized by cascading 2nd order stages. The degrees-of-freedom in this procedure are: the pole-zero assignments to form the second order transfer functions, the gain-factors for the stages and the sequence in the cascade. These freedoms will simultaneously be used to maximize the dynamic range and the noise distance of the filters. The exact solution to the problem will be obtained by dynamic programming. A rule of thumb avoiding a computer program and an example are given.
12 citations
TL;DR: An accurate high speed digital data acquisition system which records lidar data on magnetic tape is discussed, which features real-time processing of the data by means of a low cost dedicated processor.
Abstract: An accurate high speed digital data acquisition system which records lidar data on magnetic tape is discussed. It features real-time processing of the data by means of a low cost dedicated processor. The system features dual-channel recording capability, and has two built-in gain-switching amplifiers, allowing the system to accurately record the entire return signal having a dynamic range in excess of 80 dB. Dual differential inputs are used to provide excellent noise immunity.
9 citations
TL;DR: In this paper, a lock-in differential amplifier is used in the case of small signals on a large background because of its small dynamic range, which can be overcome by incorporating a lockin amplifier in the system.
Abstract: A system is described which is entirely composed of commercially available instruments. The construction of a rotating cell with two compartments is described in detail. It is furthermore shown that a differential amplifier, although applicable in most cases, cannot be used in the case of small signals on a large background because of its small dynamic range. This difficulty can be overcome by incorporating a lock‐in amplifier in the system.
6 citations
TL;DR: In this article, the nonlinear interaction between two bulk elastic waves of different polarisations is used to generate a propagating elastic wave carrying a correlation of the two input waveforms.
Abstract: The nonlinear interaction between two bulk elastic waves of different polarisations is used to generate a propagating elastic wave carrying a correlation of the two input waveforms. Measurements show the high efficiency and dynamic range of the device and a variable-delay capability is demonstrated.
3 citations
Patent•
23 May 1975TL;DR: In guidance systems such as bang-bang missiles or laser guided bombs, the cessary dynamic range is gained by switching between arrays of comparators as a function of signal strength as mentioned in this paper.
Abstract: In guidance systems such as bang-bang missiles or laser guided bombs, the cessary dynamic range is gained by switching between arrays of comparators as a function of signal strength.
2 citations
Patent•
27 Aug 1975TL;DR: In this article, the authors proposed a limiting device in the dynamic control circuit of the receiver, such that the dynamic range of a transmitted signal is limited so that no relevant information is lost in the period the human ear needs to adapt itself to rapid sound variations.
Abstract: The invention relates to transmission systems with dynamic compansion for the coded transmission of speech signals. By the use of a limiting device in the dynamic control circuit of the receiver the intelligibility is improved. The limiting device is such that the dynamic range of a transmitted signal is limited so that no relevant information is lost in the period the human ear needs to adapt itself to rapid sound variations.
TL;DR: In this article, a simple circuit is presented which allows a signal with over 100 dB of dynamic range to be recorded on a modest tape recorder, and the same curcuit in a different mode is used on replay to reproduce the original dynamic range.
Abstract: A simple circuit is presented which allows a signal with over 100 dB of dynamic range to be recorded on a modest tape recorder. No pilot track is necessary, and the same curcuit in a different mode is used on replay to reproduce the original dynamic range. There is no spectral distortion of the recorded signal, and calibration of reference levels is unnecessary.
TL;DR: In this paper, a measurement technique for the investigation of intermodulation and noise spectra from VHF transmitters operating at full power and with controlled mutual coupling is presented, and a measurement scheme is described for the analysis of the spectra.
Abstract: A measurement technique is reported for the investigation of intermodulation and noise spectra from VHF transmitters operating at full power and with controlled mutual coupling.
TL;DR: Fast coincidence and analog electronics have been developed to process signals from the scintillation and Cherenkov detectors of the triggering telescope, which forms part of the COS-B experiment for gamma ray astronomy.
Abstract: Fast coincidence and analog electronics have been developed to process signals from the scintillation and Cherenkov detectors of the triggering telescope, which forms part of the COS-B experiment for gamma ray astronomy. Design requirements and solutions for the electronics are presented, and the performance is discussed. Integrated circuits have been used extensively in order to minimise the number of components, hence volume and weight, and to optimise the reliability. The goals of a time resolution down to 3ns for a dynamic range of 1 to 30, a signal processing time of 200ns for timing and 500ns for analog analysis, a maximum temperature instability of the trigger thresholds of 2% of the typical signal amplitude over a range of 50°C and a maximum non-linearity of 1% of full scale for the pulse height analysis have been achieved.
01 Jan 1975
TL;DR: In this paper, the spectral density and total rms output noise of filters with operational amplifiers were determined by means of transformation of passive part of the filter under the condition that the noise model of the operational amplifier is known.
Abstract: Absrracr-Output noise spectral density and total rms output noise of filters with operational amplifiers can be determined by means of transformation of passive part of the filter under the condition that the noise model of the operational amplifier is known. This problem can be solved through sequential calculation of spot noise factors for cascaded passive and active parts of the transformed filter without feedback. In this paper, this approach is used for comparison and discussion of dynamic range of low-pass op-amp filters with positive and negative feedback.
TL;DR: In this paper, the spectral density of the random vibration is made to conform to a desired plot, through automatic servo techniques, and the spectrum is split into contiguous filter bandwidths, with an individual control loop for each band.
Abstract: The electrodynamic exciter is widely used to perform vibration testing. Commonly, the exciter is energized with wide-band audio random noise. The spectral density of the random vibration is made to conform to a desired plot, through automatic servo techniques. The spectrum is split into contiguous filter bandwidths, with an individual control loop for each band. Thus, any specimen resonance is equalized. Dligital equalizers have recently been introduced. Their control dynamic range is liable to be curtailed by the number of significant figures possible in the digital computations. A method of improvement is described, whereby the roundoff effect is used as a dither signal. Some control schemes have been reported using the specimen transfer-function as the basis of control. These schemes are also analyzed here and the effect of roundoff error in limiting their function is explained. Finally, the technique proved effective for simple equalization is applied to the more sophisticated multiple-signal control situation, through the application of random-flight theory. The technique maintains equalizer performance equal to that of the single-acceleration case, with negligible increase in system complexity: a long-standing goal of vibration technology.