
	Where results make sense

Topic: Thermal noise

Related Topics

Noise current

List of noise topics

Shot noise

Flicker noise

Noise level

White noise

Thermal conductivity

Ohmeter

RF shielding

Harry Nyquist

Voltage

Hardware random number generator

Audio system measurements

Atom bomb

Debye model

	Random Electrical Noise: A Literature Survey
		Thermal noise is entirely fundamental and cannot be eliminated (although the effect can be reduced by reducing or cooling the resistance).
		To verify that a noise source is indeed producing thermal noise, it may be useful to "short out" the source resistance and verify a marked reduction in resulting noise (hopefully to under 1/10 of the original value).
		Thus, the noise is identical to shot noise associated with a dc current twice as large as the reverse saturation current of the diode.
	www.ciphersbyritter.com /RES/NOISE.HTM (0 words)

	Thermal noise calculation calculator Johnson noise voltage Nyquist dBu dBV - sengpielaudio (Site not responding. Last check: )
		Thermal noise: Also called Johnson noise, is the random white noise generated by thermal agitation of electrons in a conductor or electronic device.
		It is produced by the thermal agitation of the charges in an electric conductor and is proportional to the absolute temperature of the conductor.
		The Noise factor of a transducer at a specified input frequency is the ratio of (a/b) where "a and b" are:
	www.sengpielaudio.com /calculator-noise.htm (434 words)

	Spray Acoustical and Thermal Insulation - Noise Reduction
		Spray Acoustical and Thermal Insulation - Noise Reduction
		The architectural sales team at ICC is experienced in providing effective design solutions for your thermal and acoustical requirements.
		ICC insulation and acoustical products are extremely versatile and have been installed throughout the construction industry on both new and renovation projects.
	www.spray-on.com /home (207 words)

	Resistor Types--Does It Matter?
		Thermal noise is mainly dependent on temperature, bandwidth, and resistance, while shot noise is dependent on bandwidth and average DC current, and contact noise is dependent upon average DC current, bandwidth, material geometry and type.
		Since the characteristics of thermal noise have a Gaussian probability density function, and the noise of the two separate sources is uncorrelated white noise, the total noise power is equal to the sum of the individual noise powers.
		This noise is directly proportional to both the current flowing in the resistance and a constant that depends upon the material the resistor is made of.
	www.aikenamps.com /ResistorNoise.htm (1516 words)

	Dataforth - Resistor Thermal Noise
		One common noise category is resistor thermal noise, which is the noise developed in a resistor in the absence of current flow.
		Thermal noise was modeled by Nyquest in 1928 and experimentally measured by Johnson.
		For this situation, when the thermal noise in a resistor is shunted by a non-zero capacitance (C), the mean-square voltage value is given by k*T/C. For illustration purposes, consider a resistor at 100 degrees C. with a 1 pico-farad shunt capacitance.
	www.dataforth.com /catalog/doc_1065.html (653 words)

	Digital noise
		We assume that the reason it took so long for manufacturers of consumer-grade digital still cameras to provide long exposure times and bulb settings on their cameras is that the problem of thermal noise generated in the CCD was too great.
		While thermal noise is a problem that one must deal with, it can be dealt with successfully.
		Thermal noise always exists within a CCD, and the problem increases the longer the sensor is active.
	www.hiviz.com /tools/cameras/digital/dig_noise.htm (409 words)

	Physics of thermal noise
		Although it has roots in the study of Brownian motion by Einstein in the early years of the 20th century,[3] the fundamental theoretical underpinning of our understanding of thermal noise is the Fluctuation-Dissipation Theorem.
		The thermal noise power spectrum at that point is dominated by motion in three kinds of modes: the fundamental pendulum mode, modes of the pendulum wires, and internal modes of the test mass itself.
		The smaller the dissipation, the lower the spectrum of off-resonance thermal noise.
	physics.syr.edu /~gravlab/gravity/node3.html (539 words)

	Shot noise
		Shot noise, the time-dependent fluctuations in electrical current caused by the discreteness of the electron charge, is well known to occur in solid-state devices, such as tunnel junctions, Schottky barrier diodes and p-n junctions.
		Thermal noise is thus white noise - the spectral density is independent of frequency.
		Shot noise results from the fact that the current is not a continuous flow but the sum of discrete pulses in time, each corresponding to the transfer of an electron through the conductor.
	www.lorentz.leidenuniv.nl /beenakkr/mesoscopics/topics/noise/noise.html (1334 words)

	Capgo - Understanding Noise
		Generally the aim is to maximize the signal to noise ratio by minimizing the noise, maximizing the signal or a combination of both.
		The topic of noise is a big one, but in practice you may never need to deal with the problem because the equipment you are using is effective in removing the noise or there is no significant noise present in you measurement.
		This noise is has a number of components: thermal noise, excess current noise, flicker noise and shot noise.
	www.capgo.com /Resources/Measurement/Noise/Noise.html (1583 words)

	noise analysis and reduction
		Shot noise results from the fact that the current is not a continuous flow but the sum of discrete pulses in time, each corresponding to the transfer of an electron or hole through the conductor.
		Noise in the power-supply line, which is used to bias the substrate, injected to the substrate through the contacts.
		If we assume that the noise produced by a larger transistor is mainly injected to the substrate through the junction capacitance, it will be true that the noise peak produced by a 1 to 0 logic transition has a sign opposite to the noise peak produced by a 0 to1 transition.
	geocities.com /fudinggenoise/noise.html (2768 words)

	Receiver Thermal Noise (Communications Blockset)
		The Receiver Thermal Noise block simulates the effects of thermal noise on a complex, baseband signal.
		Noise temperature - specifies the noise in degrees Kelvin
		Noise figure - specifies the noise in decibels relative to a noise temperature of 290 degrees Kelvin
	www.technion.ac.il /guides/matlab/toolbox/commblks/ref/receiverthermalnoise.html (216 words)

	4.2 Thermal Noise
		Thermal noise associated with the mirror masses and the last stage of their suspensions is likely to be the most significant noise source at the low frequency end of the operating range of long baseline gravitational wave detectors [87
		In order to estimate the internal thermal noise of a test mass, each resonant mode of the mass can be regarded as a harmonic oscillator.
		In order to keep thermal noise as low as possible the mechanical loss factors of the masses and pendulum resonances should be as low as possible.
	relativity.livingreviews.org /Articles/lrr-2000-3/node8.html (842 words)

	TSCM 101 - Noise and Sensitivity Tutorial
		Thermal noise (or thermal agitation effect) however is based on Boltzmann's constant, the temperature, and the bandwidth of the signal.
		Thermal noise is based on the kTB formula; the only part of which is within our practical control is B (or bandwidth).
		Noise is our friend in that it presents an easily calculated or modeled level, slight variations of this "floor" indicate the presence of a potential eavesdropping device, or signal that requires further investigation.
	www.tscm.com /TSCM101noise.html (1768 words)

	diyAudio Forums Archive - Thermal noise study...
		Thermal nose: Thermal noise is associated with the Brownian Movement of electrons within a conductor (taken loosely, a conductor is resistor/transistor/tube/wire -Dan).
		Noise is best characterized by the Fourier transform of the time-varying fluctuations in electric current, which is called the noise spectral density, S. For thermal noise, the spectral density is given by 4kT/R, where k is Boltzmann's constant and T is the temperature.
		Noise is IMO more likely to be a problem in a semi-conductor since it is caused by the motion of the electrons and occurs in any conductor that has a resistance, R. Since electrons travel in a vacuum in a tube,the only noise generated is by the movement of the electrons themselves.
	www.diyaudio.com /forums/showthread/t-7910.html (4094 words)

	Graduate Physics Laboratory Handbook: Thermal Noise
		From measurements of the thermal noise as a function of resistance and the shot noise as a function of diode current, values of Boltzmann's constant and the electronic charge may be calculated.
		Thermal noise may also be measured a as a function of temperature, and a value of absolute zero obtained.
		The theoretical basis for 1/f noise (so-called because its magnitude increases inversely with the frequency, f) is still a matter of active resea rch.
	www.physics.umd.edu /studinfo/courses/gradlab/glhb/noise.html (665 words)

	Rupert Neve Designs - Microphone Impedance and Noise (Site not responding. Last check: )
		Noise is heard, ideally, at an extremely low level, as a “hiss” accompanying the music signal.
		This output noise is relatively easy to measure but, as we’ve seen, it consists of the microphone source resistance noise plus the amplifier noise.
		Thermal, or pure resistor noise is a straight line whilst amplifier noise is a curve that depends upon the optimum source resistance for that particular amplifier.
	www.rupertneve.com /notes_noise.html (1213 words)

	Understanding ADC Noise for Small and Large Signal Inputs for Receiver Applications - マキシム/ダラス
		The acceptable level of ADC noise power in any particular application is calculated for the case when both a blocker and smaller signal are applied to the receiver terminal simultaneously.
		As the input level is increased further and approaches full-scale, the noise floor increases an additional 1.3dB due to ADC clock jitter to a value of -69.7dBm resulting in an effective noise figure of 28.3dB (per procedure outlined in Figure 2).
		This noise figure value should provide sufficient margin to the air-interface requirements, which is also dependent on the final detector's Eb/No (bit energy to noise power spectral density ratio) requirement.
	japan.maxim-ic.com /appnotes.cfm?an_pk=1929 (1661 words)

	Satellite Footprints by Dish Size - Noise Discussion, Terrestrial Interference (TI), Rain Fade, Free Space Loss, Earth ...
		Signal can always be amplified above the noise floor but once it gets buried in background noise (falls into the signal floor) it can not be retrieved; this is why the LNB amplifies the weak satellite signals as soon as they are received before passing them on into the cable and to your receiver.
		Interference is noise that comes in on the same frequency(ies) as signal and masks (overwhelms) parts or all of the desired signal (see diagram).
		noise from the earth in addition to signals from space, this random noise is often called earth thermal noise.
	www.geo-orbit.org /sizepgs/Noise.html (4779 words)

	Peavey.com :: Noise and Stuff in Consoles
		Thermal noise is caused by (you guessed it) heat.
		Electronic noise is usually referenced to the input of a circuit or device and stated as a noise voltage in series with the input of a perfect noiseless amplifier and a noise current in parallel with the input dumping into the input and feedback network's impedance.
		In the "backgrounded" system, the noise gain and thus the noise floor is constant; backgrounding facilitates a balanced bus for minimum crosstalk and hum pickup.
	www.peavey.com /support/technotes/mixers/noise_consoles.cfm (1446 words)

	Noise in Audio Amplifiers
		Thermal noise is "white" in character (has a constant energy per unit bandwidth) and is generated by the thermal agitation of electrons in a conductor.
		This is the equivalent of 80dB Signal to Noise ratio (S/N) relative to 0dBu.
		A common technique for low noise is to select transistors based on their noise data, which will indicate the optimum collector current for a given source impedance.
	sound.westhost.com /noise.htm (2366 words)

	Understanding ADC Noise for Small and Large Signal Inputs for Receiver Applications - Maxim/Dallas
		The acceptable level of ADC noise power in any particular application is calculated for the case when both a blocker and smaller signal are applied to the receiver terminal simultaneously.
		As the input level is increased further and approaches full-scale, the noise floor increases an additional 1.3dB due to ADC clock jitter to a value of -69.7dBm resulting in an effective noise figure of 28.3dB (per procedure outlined in Figure 2).
		This noise figure value should provide sufficient margin to the air-interface requirements, which is also dependent on the final detector's Eb/No (bit energy to noise power spectral density ratio) requirement.
	www.maxim-ic.com /appnotes.cfm/appnote_number/1929 (1708 words)

	Glossary of PA Terms - T
		In such cases a front-panel indication is usually provided to warn the user when the thermal cut-out has operated − this is usually due to prolonged overload or to connection of an inappropriately low load impedance at the speaker output(s).
		The noise that is generated in a resistance by virtue of the random motion of the atoms that make up the material.
		For example, the thermal noise level in a bandwidth of 20 kHz from a 600 ohm resistor at 20°C equates to −125 dBu unweighted (approximately −130 dBu A-weighted).
	www.btinternet.com /~paformusic/gl_t.htm (3049 words)

	Waveform Noise - School for Champions: Succeed in Physical Science
		It is called white noise because it consists of a full spectrum of waveform frequencies, similar to how white light is a combination of a full spectrum of visible colors.
		One example of electrical noise that is added to your home current can be caused by a nearby electric motor that may create an additional regular signal, which can add to your normal AC signal.
		Typically the noise is not regular, thus you take its average to determine the effect on the listener.
	www.school-for-champions.com /science/noise.htm (1019 words)

	Noise, Noise, Noise
		The various sources of noise that exist in CCD imagers will be discussed, along with an explanation of the causes of each type of noise and a description of the methods used to correct for each example.
		In this manner, thermal noise produced by the heat generated by the device’s electronics and contributions of light to the exposure are at a minimum, thereby isolating the effect of read noise.
		The electrons generated by thermal noise exists even when light does not hit the detector surface, and is referred to as dark current.
	www.astrophys-assist.com /educate/noise/noise.htm (4329 words)

	Quasi-thermal Noise
		The intensity and frequency spectrum of the quasi-thermal noise depends on plasma parameters such as the density and temperature, so those parameters can be deduced by measuring the quasi-thermal noise signal.
		The interplanetary medium is not in thermal equilibrium and thus cannot be described by a single temperature.
		The quasi-thermal noise can, under ideal conditions, yield values for the density and temperature of these components, and for the solar wind velocity.
	urap.gsfc.nasa.gov /www/quasi_thermal_noise.html (291 words)

	PRISM - Radar - Subnoise Signal Recovery
		Coherent noise, mainly arising from within the radar system itself, is immune to the noise suppression benefits of stacking and dithering.
		The coherent noise, on the other hand, does not experience the alternating 0/π phase shift so that when it is received and it experiences the compensating phase shift of the odd-numbered pulses, it adds destructively with the sample of coherent noise that accompanied the even-numbered pulse.
		Overall, the total noise power between 10 and 50 MHz after 1 million average is about -106 dBm, a reduction of about 25 dB compared to the previous case that did not employ 0/π phase modulation.
	ku-prism.org /update/radarteam/subnoise.html (1436 words)

	linrad support: A low noise, four phase crystal oscillator.
		The flat noise floor at the collector side may be a good deal better than this even if the amplifier impedance is matched to, or lower than the resistive part of the crystal impedance.
		This is because the voltage gain for the thermal noise produced within the crystal drops quickly with the frequency separation since the reactive part of the crystal impedance comes in series with the noisy 4 ohm resistive part.
		The flat noise floor can be made much lower than one would expect from comparing noise power to signal power using the noise figure and feed impedance at the resonance frequency of the crystal.
	www.nitehawk.com /sm5bsz/linuxdsp/rxiq/osc.htm (1722 words)

	Thermal noise Details, Meaning Thermal noise Article and Explanation Guide
		The noise power, P, in watts, is given by P = 4kT Δf, where k is Boltzmann's constant in joules per kelvin, T is the conductor temperature in kelvins, and Δf is the bandwidth in hertz.
		Thermal noise power, per hertz, is equal throughout the frequency spectrum, depending only on k and T.
		Thermal noise is intrinsic to all resistors and is not a sign of poor design or manufacture, although resistors may also have excess noise.
	www.e-paranoids.com /t/th/thermal_noise.html (180 words)

Try your search on: Qwika (all wikis)