Measurements and analysis of the noise spectral density of YBCO films

2006 ◽  
Vol 203 (11) ◽  
pp. 2944-2949
Author(s):  
A. Taoufik ◽  
M. Bghour ◽  
A. Labrag ◽  
A. Bouaaddi ◽  
A. Abaragh ◽  
...  
Keyword(s):  
Spectral Density ◽  
Noise Spectral Density ◽  
Ybco Films

scholarly journals Thermal noise limit for ultra-high vacuum noncontact atomic force microscopy

2013 ◽  
Vol 4 ◽  
pp. 32-44 ◽  
Author(s):  
Jannis Lübbe ◽  
Matthias Temmen ◽  
Sebastian Rode ◽  
Philipp Rahe ◽  
Angelika Kühnle ◽  
...  
Keyword(s):  
Atomic Force Microscopy ◽  
Signal Processing ◽  
Transfer Function ◽  
Spectral Density ◽  
Thermal Noise ◽  
Noise Spectral Density ◽  
Force Microscopy ◽  
Atomic Force ◽  
Noise Limit ◽  
Signal Processing Electronics

The noise of the frequency-shift signal Δf in noncontact atomic force microscopy (NC-AFM) consists of cantilever thermal noise, tip–surface-interaction noise and instrumental noise from the detection and signal processing systems. We investigate how the displacement-noise spectral density d z at the input of the frequency demodulator propagates to the frequency-shift-noise spectral density d Δ f at the demodulator output in dependence of cantilever properties and settings of the signal processing electronics in the limit of a negligible tip–surface interaction and a measurement under ultrahigh-vacuum conditions. For a quantification of the noise figures, we calibrate the cantilever displacement signal and determine the transfer function of the signal-processing electronics. From the transfer function and the measured d z , we predict d Δ f for specific filter settings, a given level of detection-system noise spectral density d z ds and the cantilever-thermal-noise spectral density d z th. We find an excellent agreement between the calculated and measured values for d Δ f . Furthermore, we demonstrate that thermal noise in d Δ f , defining the ultimate limit in NC-AFM signal detection, can be kept low by a proper choice of the cantilever whereby its Q-factor should be given most attention. A system with a low-noise signal detection and a suitable cantilever, operated with appropriate filter and feedback-loop settings allows room temperature NC-AFM measurements at a low thermal-noise limit with a significant bandwidth.

Extension of the frequency range of the noise spectral density in silicon p-n structures irradiated with gamma-ray quanta

2001 ◽  
Vol 35 (3) ◽  
pp. 338-342 ◽  
Author(s):  
O. K. Baranovskii ◽  
P. V. Kuchinskii ◽  
V. M. Lutkovskii ◽  
A. P. Petrunin ◽  
E. D. Savenok
Keyword(s):  
Spectral Density ◽  
Gamma Ray ◽  
Frequency Range ◽  
Noise Spectral Density

scholarly journals Origin of the Low-Frequency Noise in the Asymmetric Self-Cascode Structure Composed by Fully Depleted SOI nMOSFETs

2017 ◽  
Vol 12 (2) ◽  
pp. 62-70
Author(s):  
Rafael Assalti ◽  
Rodrigo T. Doria ◽  
Denis Flandre ◽  
Michelly De Souza
Keyword(s):  
Spectral Density ◽  
Gate Voltage ◽  
Low Frequency ◽  
Drain Current ◽  
Current Noise ◽  
Frequency Noise ◽  
Low Frequency Noise ◽  
Noise Spectral Density ◽  
Fully Depleted ◽  
Self Cascode

In this paper the origin of low-frequency noise in the Asymmetric Self-Cascode (A-SC) structure composed by Fully Depleted SOI nMOSFETs is investigated through experimental results. It is shown that the predominant noise source of the A-SC structure is linked to carrier number fluctuations, being governed by the noise generated in the transistor near the source. Larger channel doping concentrations degrade the quality of the Si-SiO2 interface and the gate oxide, which causes an increase of the normalized drain current noise spectral density, just as the reduction of the gate voltage overdrive, since there are few carriers in the channel. The A-SC structures have showed higher noise compared with single transistors. In saturation regime, the increase of the gate voltage overdrive has incremented the corner frequency, shifting the g-r noise to higher frequencies. Besides that, the normalized noise has been significantly increased when compared with the linear regime due to the rise of the drain current noise spectral density.

PHYSICAL MODEL OF THE CURRENT NOISE SPECTRAL DENSITY VERSUS DARK CURRENT IN CdTe DETECTORS

2001 ◽  
Author(s):  
Asaad Imad ◽  
Bernard Orsal ◽  
Robert Alabedra ◽  
Marc Arques ◽  
Guillaume Montémont ◽  
...  
Keyword(s):  
Spectral Density ◽  
Physical Model ◽  
Dark Current ◽  
Current Noise ◽  
Noise Spectral Density
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