Dynamic range

About: Dynamic range is a research topic. Over the lifetime, 7576 publications have been published within this topic receiving 101739 citations. The topic is also known as: DNR & DR.

CIX: a detector for spectrally enhanced x-ray imaging by simultaneous counting and integrating

Abstract: A hybrid pixel detector based on the concept of simultaneous charge integration and photon counting will be presented. The second generation of a counting and integrating X-ray prototype CMOS chip (CIX) has been operated with different direct converting sensor materials (CdZnTe and CdTe) bump bonded to its 8x8 pixel matrix. Photon counting devices give excellent results for low to medium X-ray fluxes but saturate at high rates while charge integration allows the detection of very high fluxes but is limited at low rates by the finite signal to noise ratio. The combination of both signal processing concepts therefore extends the resolvable dynamic range of the X-ray detector. In addition, for a large region of the dynamic range, where counter and integrator operate simultaneously, the mean energy of the detected X-ray spectrum can be calculated. This spectral information can be used to enhance the contrast of the X-ray image. The advantages of the counting and integrating signal processing concept and the performance of the imaging system will be reviewed. The properties of the system with respect to dynamic range and sensor response will be discussed and examples of imaging with additional spectral information will be presented.

Wide dynamic range silicon diaphragm vacuum sensor by electrostatic servo system

Abstract: A wide dynamic range silicon diaphragm vacuum sensor by an electrostatic servo system and an electrical circuit for servo control have been made. In nonservo mode, i.e., when the sensor was used as a capacitive vacuum sensor, a linear characteristic between pressure and output voltage was obtained in the pressure range from 0.1 to 100 Pa. On the other hand, the square root of the servo voltage was proportional to the pressure in a wide pressure range from 0.1 to 530 Pa in servo mode. The servo mechanism is effective for widening the dynamic range of vacuum sensors.

A vision sensor with on-pixel ADC and in-built light adaptation mechanism

Abstract: In this paper we propose an on-pixel Analogue-to-Digital Converter (ADC) based on pulse frequency modulation (PFM) scheme. This PFM based converter presents a viable solution for pixel-level based ADC. It uses a simple and robust circuit that can be implemented in a compact area resulting in a 23% fill-factor for a digital vision sensor in 0.25 μm CMOS technology. An in-built light adaptation mechanism has also been implemented which allows the sensor to better adapt to low-light intensity or to adjust the sensor saturation level. As a consequence, the proposed sensor features a programmable dynamic range. Image lag is eliminated since a reset of the photodetector is performed after the conversion period. A prototype comprising a 32 X 32 pixel array has been implemented in CMOS 0.25 μm technology. Each pixel occupies an area of 45 X 45 μm 2 with an average power consumption of 85 μW per pixel.

A Linear Dynamic Range Receiver With Timing Discrimination for Pulsed TOF Imaging LADAR Application

Abstract: This paper presents a linear and wide dynamic range (DR) receiver for pulsed time-of-flight imaging laser detection and ranging application, which can capture the pulsed echo intensity. The alternative leading edge timing discrimination scheme with two threshold voltages by differential voltage shift is utilized to compensate the walk error, and thus accurately obtain timing information. The proposed receiver was implemented and fabricated in a 0.18- $\mu \text{m}$ CMOS technology. The receiver achieves a high differential transimpedance gain of 106 dB $\Omega $ , a wide differential output swing of about 1.8 V, an input-referred noise current of 4.55 pA/Hz0.5 and a minimum detectable signal of about $0.28~\mu $ Arms at SNR = 5, leading to a linear DR of 66 dB with a 3.3-V power supply. The area of the receiver chip is equal to $0.95\times0.95$ mm2.

Sensitive signal detection using a feed-forward oscillator network

Abstract: We present the results of an experimental investigation of a network of nonlinear coupled oscillators which are coupled in feed-forward mode. By exploiting the nonlinear response of each oscillator near its intrinsic Hopf bifurcation point, we have found remarkable amplification of small signals over a narrow bandwidth with a large dynamic range. The effect is exploited to extract a small amplitude periodic signal from an input time series which is dominated by noise. Specifically, we have used this relatively simple experimental system to measure responses with a bandwidth of approximately 1% of the central frequency, amplifications of approximately 60 dB, and a dynamic range of approximately 80 dB and can extract signals from a time series with a signal to noise ratio of approximately -50 dB.