High dynamic range

About: High dynamic range is a research topic. Over the lifetime, 4280 publications have been published within this topic receiving 76293 citations. The topic is also known as: HDR.

Very high dynamic range and high-sampling rate VME digitizing boards for physics experiments

Abstract: The trend in data acquisition systems for modern physics experiments is to digitize analog signals closer and closer to the detector. The digitization systems have followed the progress of commercial analog to digital converters. The state of the art for these devices is currently limited to 200 MHz, for a 10 to 12 bits range. Faster ADCs, originally dedicated to military applications are also available, but their resolution is lower and they are much more expensive. The new board, described in this paper, has been designed to improve these performances by an order of magnitude. In its simplest version, this board includes mainly 4 channels of 12-bit resolution digitizers sampling analog data up to 2 GSample/s with an analog bandwidth of 300 MHz. It is based on the custom-designed MATACQ chip. Its innovative design allows to reach these performances with a power consumption smaller than 1 W. The boards are triggerable either by internal or external signals and several boards are easily synchronizable. The board integrates both a GPIB and a VME interface that permits a maximum readout speed of 500 event/s with all the memory cells of the 4 channels read. Several other read-out modes allowing to read only a set of limited set of cells or of channels are available for faster operation.

A broadband high-dynamic-range voltage-controlled attenuator MMIC with an IIP3 > +47 dBm over entire 30-dB analog control range

Abstract: In this paper we introduce a novel design technique for broadband high dynamic range absorptive voltage controlled attenuators (VCA) on SOI CMOS. The VCA design is based on the classical passive FET ‘Pi’ and ‘Tee’ attenuator structures but uses stacked FET techniques to dramatically improve the signal handling capability. The VCA has >30dB attenuation range over a frequency band from DC to > 5GHz and achieves an IIP3 of > +47dBm over the entire analog control range. The use of a stacked FET structure evenly distributes the RF signal across ‘N’ FET devices thus reducing the 3rd order distortion generated by each individual FET. The reduction in distortion gained is directly proportional to the degree of stacking used.

A Wide Linear Dynamic Range Image Sensor Based on Asynchronous Self-Reset and Tagging of Saturation Events

Abstract: We report a high dynamic range (HDR) image sensor with a linear response that overcomes some of the limitations of sensors with pixels with self-reset operation. It operates similar to an active pixel sensor, but its pixels have a novel asynchronous event-based overflow detection mechanism. Whenever the pixel voltages at the integration capacitance reach a programmable threshold, the pixels self-reset and send out asynchronously an event indicating this. At the end of the integration period, the voltage at the integration capacitance is digitized and readout. Combining this information with the number of events fired by each pixel, it is possible to render linear HDR images. Event operation is transparent to the final user. There is no limitation for the number of self-resets of each pixel. The output data format is compatible with frame-based devices. The sensor was fabricated in the AMS 0.18- $\mu \text{m}$ HV technology. A detailed system description and experimental results are provided in this paper. The sensor can render images with an intra-scene dynamic range of up to 130 dB with linear outputs. The pixels’ pitch is 25 $\mu \text{m}$ and the sensor power consumption is 58.6 mW.

Apparatus and method for obtaining motion adaptive high dynamic range image

Abstract: Disclosed is an apparatus and method for obtaining a motion adaptive high dynamic range image, in which a motion degree of a first image and a second taken using different exposure times is calculated. The motion calculation intensity is adjusted based on the calculated motion degree. The motion compensation intensity involves a global motion compensation and/or a location motion compensation. Images subjected to compensation are synthesized and output, so that an image having high dynamic range is obtained.

High dynamic range x-ray detector with improved signal to noise ratio

Abstract: An x-ray detector and its pixel circuit are described, that allow to cover a large dynamic range with automatic selection of the sensitivity setting in each pixel, thus providing improved signal to noise ratio with all exposure levels. X-ray detectors are required to cover a large dynamic range. The largest exposure determines the required pixel capacitance. However, a large pixel capacitance gives a bad signal to noise ratio with small exposures e.g. in the dark parts of the image. This invention disclosure describes several approaches to provide automatic sensitivity selection in the pixels. This ensures that low signals are stored in a small capacitor or read out with a high sensitivity with corresponding good signal to noise ratio, while larger signals are stored in larger capacitors or are read out with lower sensitivity so that no information is lost.