Showing papers on "High dynamic range published in 1987"

High dynamic range fiber optical link

Abstract: Apparatus, and a corresponding method for its use, for modulating an optical carrier signal with a radio-frequency signal and providing a desirably high dynamic range. An optical signal source is split into a carrier signal and a reference signal, ideally with an optical star coupler, and the carrier signal is phase-modulated with the radio-frequency signal by means of a Pockels cell, producing a phase-modulated signal devoid of even-harmonic distortion, and containing only relatively small odd-harmonic components. In the preferred embodiment of the invention, the phase-modulated signal has its carrier signal suppressed. Then the resulting double-side-band suppressed-carrier signal is combined with the reference signal, preferably with another optical star coupler, to produce the desired modulated optical signal with high dynamic range.

Characterization Of A Charge-Injection-Device Camera System As A Multichannel Spectroscopic Detector

Abstract: A solid-state camera system designed for use as a multichannel detection system for spectroscopic applications is evaluated. The camera is based on a charge-injection-device sensor that permits very high dynamic range operation by virtue of its unique nondestructive readout capability. Methods of determining gain and readout noise are discussed. Performance of the camera system is evaluated with respect to sensitivity, linearity, readout noise, and dynamic range. The use of nondestructive readout to reduce effective readout noise and increase dynamic range is described. Spectral responses in the visible and ultraviolet of coronene-coated and uncoated devices are reported. Various time-dependent anomalies caused by interface trapped charge are discussed.

Analog integrated circuits with high dynamic range

Abstract: a corresponding dynamic range of close to 100 dB. The dynamic range of analog circuits is limited on one side by noise and by distortion on the other side. Noise is inherently higher in MOST technologies than in bipolar ones. But noise can be suppressed by chopping and correlated double sampling techniques. They are easier to implement in MOST technologies because of the availability of switches and capacitors. However switching introduces noise by itself as well. Causes are clock feedthrough and frequency band folding. These limitations are particularly harmful at high frequencies. Distortion is generated by all active devices if the current swing is high. Switched capacitor circuits seem to be free from distortion because only passive devices and operational ampifiers with high gain are used. However the charging and discharging of the capacitances is never complete. Distortion of the waveform is thus introduced, again especially at high frequencies. Since the dynamic range is limited most at high frequencies, the question arises whether GaAs integrated circuits perform better at

Clamping circuit in analog/digital converter

Abstract: PURPOSE:To attain a digital conversion with high stability and high dynamic range by controlling a conversion minimum grade level in an A/D converter at the optimum level CONSTITUTION:A digital video signal from an A/D converter 2 is compared with the output of a clamp level setting circuit 16 at a comparator 15, and when the output of the A/D converter 2 is larger, signals of H and L are outputted respectively to AND gates 17 and 18 A clamp pulse from a clamp pulse generation circuit 19 is inputted to the AND gates 17 and 18, and either of analog switches 20 or 21 is turned on, and a voltage of positive polarity from a reference power source 22, or a voltage of negative polarity from a reference power source 23 is supplied to an estimating capacitor 26, and an electric charge is accumulated or discharged The output voltage of the capacitor 26 is inputted to an adder circuit 11 through a buffer amplifier 27, and the lowest grade DC level of the video signal is decided

High Dynamic Range Integrated-Optic Spectrum Analyzer Using Total Internal Reflection in a Waveguide

Abstract: An integrted-optoc spectrum analyzer, using total internal reflection in a waveguide, is proposed and demonstrated. For real time multifrequency analysis, a low diffraction efficiency operation is required to operate under conditions of low level spurious components generation. The proposed structure, which has been fabricated on Z-cut LiNbO3, makes it possible to realize a high dynamic range at a few percent diffraction efficiency. The completed device has exhibited a 25–28 dB RF dynamic range in multifrequency analyzing operation.