scholarly journals High-Sensitivity Large-Area Photodiode Read-Out Using a Divide-and-Conquer Technique

Sensors ◽  
2020 ◽  
Vol 20 (21) ◽  
pp. 6316
Author(s):  
Guillermo Royo ◽  
Carlos Sánchez-Azqueta ◽  
Concepción Aldea ◽  
Santiago Celma
Keyword(s):  
Traditional Approach ◽  
Signal To Noise Ratio ◽  
High Sensitivity ◽  
Divide And Conquer ◽  
Transimpedance Amplifier ◽  
Large Area ◽  
Signal To Noise ◽  
Remarkable Improvement ◽  
The Core ◽  
Novel Technique

In this letter, we present a novel technique to increase the sensitivity of optical read-out with large integrated photodiodes (PD). It consists of manufacturing the PD in several pieces, instead of a single device, and connecting a dedicated transimpedance amplifier (TIA) to each of these pieces. The output signals of the TIAs are combined, achieving a higher signal-to-noise ratio than with the traditional approach. This work shows a remarkable improvement in the sensitivity and transimpedance without the need for additional modifications or compensation techniques. As a result, an increase in sensitivity of 7.9 dBm and transimpedance of 8.7 dBΩ for the same bandwidth is achieved when dividing the photodiode read-out into 16 parallel paths. The proposed divide-and-conquer technique can be applied to any TIA design, and it is also independent of the core amplifier structure and fabrication process, which means it is compatible with every technology allowing the integration of PDs.

scholarly journals Hot Exoplanet Atmospheres Resolved with Transit Spectroscopy (HEARTS)

2020 ◽  
Vol 643 ◽  
pp. A45 ◽  
Author(s):  
J. V. Seidel ◽  
M. Lendl ◽  
V. Bourrier ◽  
D. Ehrenreich ◽  
R. Allart ◽  
...  
Keyword(s):  
Large Scale ◽  
Signal To Noise Ratio ◽  
High Sensitivity ◽  
High Accuracy ◽  
Scale Height ◽  
Light Curves ◽  
Signal To Noise ◽  
System Parameters ◽  
The Core

WASP-127b is one of the puffiest exoplanets found to date, with a mass of only 3.4 Neptune masses, but a radius larger than that of Jupiter. It is located at the border of the Neptune desert, which describes the lack of highly irradiated Neptune-sized planets, and which remains poorly understood. Its large scale height and bright host star make the transiting WASP-127b a valuable target to characterise in transmission spectroscopy. We used combined EulerCam and TESS light curves to recalculate the system parameters. Additionally, we present an in-depth search for sodium in four transit observations of WASP-127b, obtained as part of the Hot Exoplanet Atmosphere Resolved with Transit Spectroscopy (HEARTS) survey with the High Accuracy Radial velocity Planet Searcher (HARPS) spectrograph. Two nights from this dataset were analysed independently by another team. The team claimed a detection of sodium that is incompatible with previous studies of data from both ground and space. We show that this strong sodium detection is due to contamination from telluric sodium emissions and the low signal-to-noise ratio in the core of the deep stellar sodium lines. When these effects are properly accounted for, the previous sodium signal is reduced to an absorption of 0.46 ± 0.20% (2.3σ), which is compatible with analyses of WASP-127b transits carried out with other instruments. We can fit a Gaussian to the D2 line, but the D1 line was not detected. This indicates an unusual line ratio if sodium exists in the atmosphere. Follow-up of WASP-127 at high resolution and with high sensitivity is required to firmly establish the presence of sodium and analyse its line shape.

Image Acquisition Using Non-Pixeled Amorphous Silicon Based Sensors

2001 ◽  
Vol 685 ◽  
Author(s):  
M. Fernandes ◽  
Yu. Vygranenko ◽  
J. Martins ◽  
M. Vieira
Keyword(s):  
Amorphous Silicon ◽  
Signal To Noise Ratio ◽  
Image Acquisition ◽  
Short Circuit ◽  
Acquisition Time ◽  
Large Area ◽  
Signal To Noise ◽  
Scanning Beam ◽  
Noise Ratio ◽  
Silicon Based

AbstractWe suggest to enhance the performance of image acquisition systems based on large area amorphous silicon based sensors by optimizing the readout parameters such as the intensity and cross-section of scanner beam, acquisition time and bias conditions. The main output device characteristics as image responsivity, signal to noise ratio and spatial resolution were analyzed in open circuit, short circuit and photodiode modes. The result show that the highest signal to noise ratio and best dark to bright ratio can be achieved in short circuit mode.It was shown that the sensor resolution is related to the basic device parameters and, in practice, limited by the acquisition time and scanning beam properties. The scanning beam spot size limits the resolution due to the overlapping of dark and illuminated zones leading to a blurring effect on the final image and a consequent degradation in the resolution.

scholarly journals An Integrated Cross Layer Design to Enhance the Quality of Service of Video Streaming in Mobile Adhoc Networks

2018 ◽  
Vol 7 (2) ◽  
pp. 57
Author(s):  
N. Gomathi ◽  
M. Uvaneshwari
Keyword(s):  
Signal To Noise Ratio ◽  
Transport Layer ◽  
Application Layer ◽  
Font Size ◽  
Signal To Noise ◽  
Mapping Algorithm ◽  
Novel Technique ◽  
Dynamic Mapping ◽  
Multipath Transport ◽  
Description Coding

<span style="font-size: 9.0pt; font-family: 'Times New Roman',serif; mso-fareast-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA;">The intent of this paper is to put forth a novel technique for improvising the QoS of multimedia applications in by using Modified dynamic mapping algorithm and Multipath transport(MPT) and Multi Description Coding(MDC). The improvement is attained by applying the MDC at application layer along with UDPLite in transport layer and multipath at network layer and Modified dynamic mapping in MAC Layer.Thismethod attains an increase of 30.84% in Peak Signal to Noise Ratio (PSNR) and 18.57% decrease in delay in contrast to the conventional methods.</span><table class="MsoTableGrid" style="width: 444.85pt; border-collapse: collapse; border: none; mso-border-alt: solid windowtext .5pt; mso-yfti-tbllook: 1184; mso-padding-alt: 0in 5.4pt 0in 5.4pt;" width="593" border="1" cellspacing="0" cellpadding="0"><tbody><tr style="mso-yfti-irow: 0; mso-yfti-firstrow: yes; mso-yfti-lastrow: yes; height: 63.4pt;"><td style="width: 290.6pt; border: none; border-top: solid windowtext 1.0pt; mso-border-top-alt: solid windowtext .5pt; padding: 0in 5.4pt 0in 5.4pt; height: 63.4pt;" valign="top" width="387"><p class="MsoNormal" style="margin-top: 6.0pt; text-align: justify;"><span style="font-size: 9.0pt;">The intent of this paper is to put forth a novel technique for improvising the QoS of multimedia applications in by using Modified dynamic mapping algorithm and Multipath transport(MPT) and Multi Description Coding(MDC). The improvement is attained by applying the MDC at application layer along with UDPLite in transport layer and multipath at network layer and Modified dynamic mapping in MAC Layer.Thismethod attains an increase of 30.84% in Peak Signal to Noise Ratio (PSNR) and 18.57% decrease in delay in contrast to the conventional methods.</span></p></td></tr></tbody></table>

scholarly journals Differential Recordings of Local Field Potential:A Genuine Tool to Quantify Functional Connectivity

2018 ◽  
Author(s):  
Meyer Gabriel ◽  
Caponcy Julien ◽  
Paul A. Salin ◽  
Comte Jean-Christophe
Keyword(s):  
Functional Connectivity ◽  
Local Field ◽  
Signal To Noise Ratio ◽  
Field Potential ◽  
Low Frequency ◽  
Large Area ◽  
Signal To Noise ◽  
Cortical Areas ◽  
Electrophysiological Method ◽  
Local Field Potential Lfp

AbstractLocal field potential (LFP) recording is a very useful electrophysiological method to study brain processes. However, this method is criticized for recording low frequency activity in a large area of extracellular space potentially contaminated by distal activity. Here, we theoretically and experimentally compare ground-referenced (RR) with differential recordings (DR). We analyze electrical activity in the rat cortex with these two methods. Compared with RR, DR reveals the importance of local phasic oscillatory activities and their coherence between cortical areas. Finally, we show that DR provides a more faithful assessment of functional connectivity caused by an increase in the signal to noise ratio, and of the delay in the propagation of information between two cortical structures.

A Carbon-Based DNA Framework Nano–Bio Interface for Biosensing with High Sensitivity and a High Signal-to-Noise Ratio

ACS Sensors ◽  
2020 ◽  
Vol 5 (12) ◽  
pp. 3979-3987
Author(s):  
Jing Su ◽  
Wenhan Liu ◽  
Shixing Chen ◽  
Wangping Deng ◽  
Yanzhi Dou ◽  
...  
Keyword(s):  
Signal To Noise Ratio ◽  
High Sensitivity ◽  
High Signal ◽  
Signal To Noise ◽  
Noise Ratio ◽  
Carbon Based

Performance Data of a New 2048 X 2048 Pixel Slow-Scan CCD Camera For TEM

2000 ◽  
Vol 6 (S2) ◽  
pp. 732-733
Author(s):  
S.A. Hiller ◽  
B. Kabius ◽  
W. Probst ◽  
H. Tröster ◽  
M. Trendelenburg ◽  
...  
Keyword(s):  
Low Dose ◽  
Signal To Noise Ratio ◽  
Ccd Camera ◽  
High Sensitivity ◽  
Signal To Noise ◽  
Ideal Image ◽  
Main Disadvantage ◽  
Ccd Arrays ◽  
Holographic Reconstruction ◽  
The Ideal

Excellent linearity and high sensitivity have made SSCs the ideal image detector for almost every TEM application. Their ability to make high quality digital images available within fraction of seconds for further evaluation and processing in a PC, have made them a non-dispensable accessory for any modern TEM. However, despite their excellent characteristics, SSCs provide a restricted number of individual image points in respect to a negative, what is considered to be the main disadvantage of this detector. To compensate for this, CCDs with 2048x2048 pixel are available since some time. SSCs using these 2kx2k CCD arrays not only provide 4 times the pixel number but also offer a lot more options people have waiting for: e. g. highly resolved low-dose or ESI images with significantly improved signal to noise ratio, or higher resolved images for diffraction analysis and holographic reconstruction.

scholarly journals Shielding of Piezoelectric Ultrasonic Probes in Hall Effect Imaging

1998 ◽  
Vol 20 (3) ◽  
pp. 206-220 ◽  
Author(s):  
Han Wen ◽  
Eric Bennett ◽  
David G. Wiesler
Keyword(s):  
Hall Effect ◽  
Electromagnetic Interference ◽  
Thermal Noise ◽  
Signal To Noise Ratio ◽  
High Sensitivity ◽  
Excitation Pulse ◽  
Signal To Noise ◽  
Coherent Noise ◽  
Electrical Pulses ◽  
Coupling Mechanisms

This paper addresses significant sources of electromagnetic noise in Hall effect imaging. Hall effect imaging employs large electrical pulses for signal generation and high sensitivity ultrasonic probes for signal reception. Coherent noise arises through various coupling mechanisms between the excitation pulse and the probe. In this paper, the coupling mechanisms are experimentally isolated and theoretically analyzed. Several methods of shielding the probe from electromagnetic interference are devised and tested. These methods are able to reduce the noise to levels below the random thermal noise, thereby improving the signal-to-noise ratio in HEI by two orders of magnitude.

scholarly journals Determination of Histamine in Tomatoes by Capillary Electrophoresis

2000 ◽  
Vol 83 (1) ◽  
pp. 89-94 ◽  
Author(s):  
Elek Bolygo ◽  
Paul A Cooper ◽  
K Michael Jessop ◽  
Frank Moffatt
Keyword(s):  
Capillary Electrophoresis ◽  
Signal To Noise Ratio ◽  
High Sensitivity ◽  
Flow Cell ◽  
Voltage Gradient ◽  
Signal To Noise ◽  
Tomato Fruits ◽  
Endogenous Level ◽  
Selection Of

Abstract An improved capillary electrophoresis assay for histamine in crude extracts was developed and used to determine histamine levels in a selection of tomato fruits and pastes. Performance in terms of reproducibility and sensitivity was optimized by use of a high sensitivity detector flow cell, sodium hydroxide rinses, and a voltage gradient. The method was linear down to 0.2 μg/mL (signal-to-noise ratio = 4:1), which was below the endogenous level in all samples.

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