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.

An instantaneous response CMOS optical receiver IC with wide dynamic range and extremely high sensitivity using feed-forward auto-bias adjustment

Abstract: An instantaneous response CMOS optical-receiver IC is described with wide input dynamic range and high sensitivity. In a TCM (time compression multiplexing)-TDMA (time division multiple access) fiber-optic subscriber system, a receiver should be able to handle burst-data packets with different amplitude. This requires quick response and a wide dynamic range. Instantaneous response is achieved with a new feed-forward auto-bias adjustment technique. In addition, multistaged offset compensation provides a wide dynamic range without any external elements and adjustments. Using these design techniques, an optical receiver IC was fabricated in a standard 0.8-/spl mu/m CMOS technology. The receiver has a wide dynamic range of more than 25 dB for burst-mode optical input at 29 Mb/s. It has high transimpedance gain of 150 dB/spl Omega/ and high sensitivity of -42 dBm with stable operation for FET threshold voltage and power supply voltage fluctuation. >

Solid state image pickup device, camera, and driving method of solid state image pickup device

Abstract: A solid state image pickup device which can properly widen a dynamic range is provided. Carriers which have overflowed from photodiodes 1003 a to 1003 c to lateral overflow regions 1010 a to 1010 c and carriers accumulated in the photodiodes 1003 a and 1003 b are transferred to FD regions 1005 a to 1005 c . Signals based on those carriers are added and held in a signal level holding capacitor Cs and read out therefrom, thereby widening the dynamic range.

Design of Phase-Differentiated Reconfigurable Array Antennas With Minimum Dynamic Range Ratio

Abstract: In this letter, we propose a real-coded genetic algorithm (GA) for optimal design of reconfigurable dual-beam linear array antennas with phase only control. The problem is to find a common amplitude distribution with minimum dynamic range ratio (DRR) that will generate a pencil beam with zero phases and a flat-top beam with continuously controllable phases of an analog phase shifter. Results are also shown for the same design without minimizing dynamic range ratio (amax /amin) of excitation amplitude

Digital image display improvement system and method

Abstract: A technique is disclosed for enhancing discrete pixel images in accordance with a desired dynamic range, such as the dynamic range of a softcopy display. Adaptive equalization is first performed on the image data to reduce overall differences between high and low intensity values, while maintaining the overall appearance of light and dark regions of the reconstructed image. Adaptive contrast boosting or enhancement is then performed on the equalized values to bring out details visible by virtue of the enhanced local contrast. The contrast enhancement may include non-linear mapping of a mid-frequency boosted image onto the dynamic range of the softcopy display.

A photon counting CdTe gamma- and X-ray camera

Abstract: A photon counting CdTe imaging camera suitable for gamma- and X-ray detection has been developed and tested. The current full active imaging area of the gamma/X-ray camera covers 44×44 mm 2 . The camera is built of eight individual detector hybrids each consisting of a pixelated CdTe detector with dimensions of 22×11 mm 2 and solder bump-bonded to a photon counting custom-designed application specific integrated circuit (ASIC). The ASICs are realized in a mixed signal, 0.35 μm 4 metal 2 poly CMOS process. The effective pixel size (image pixel pitch) is 0.5 mm. To enable higher count rate imaging and to achieve better position resolution in X-ray CT scanning each pixel is divided both on the CdTe detector and on the ASIC into two sub-pixels with dimensions 0.25×0.5 mm 2 . Every pixel circuit has two preamps each connected to one sub-pixel and feeding signal to a separate comparator. The digital pulses of the two distinct comparators are recorded by one common 8-bit counter. The amplifier offsets can be adjusted individually with 3-bit accuracy to compensate for process mismatch. A similar 3-bit gain tuning common to the two amplifiers in one pixel circuit is also implemented. A globally tuneable threshold voltage generated externally with high accuracy is used for energy discrimination. The camera can be operated both in the real time imaging mode with a maximum speed of 100 frames/s and in the accumulation mode with user adjustable counting time. Experimental data collected from a fully operational eight hybrid gamma/X-ray camera is presented and compared to simulated data. The camera exhibits excellent sensitivity and a dynamic range of 1:14,000,000. A sharp line spread function indicates the spatial resolution to be limited only by the pixel size (0.5 mm). A single pixel energy resolution of FWHM 4.7 keV at 122 keV (3.9%) was determined from measured 57 Co spectra. The peak width of the spectrum combined from all pixels was somewhat larger due to calibration inaccuracy. The photopeak efficiency was estimated from 241 Am spectra to be 60%. The developed gamma/X-ray camera is intended for back scattering imaging and as a building block in future nuclear medicine and CT scanning systems and promises highly improved performance in these applications in comparison to conventional technology.