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Topic: Noise equivalent power

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List of noise topics

Federal Standard 1037C

	LO Phase Noise Report
		Noise contributions are based on the mixer(s) having symmetrical upper and lower side-band power spectral density characteristics (additional information regarding SysCalc's SSB noise modeling can be found in Mathematical Definitions and Derivations).; therefore, the total mixer noise power is based on twice the equivalent SSB noise power in the bandwidth defined by the system.
		The equivalent SSB power due to the composite power spectral density of all contributing mixers is computed in the LO Modulation report type.
		The power is a function of the integration range and mixer(s) SSB power spectral density.
	www.ardentech.com /WebHelp/Reports/LO_Phase_Noise_Report.htm (1022 words)

	Laser Focus World - Rising above the noise
		Noise can originate in the signal itself or in the detection system, but the first step in improving measurement quality is to minimize the noise from the environment.
		The NEP is related to the total noise current by the responsivity of the detector at the wavelength being measured, R(l).
		So if the noise sources generate a current on the order of, say, tens of nanoamps at the signal wavelength, the signal will be competing with the equivalent of tens of nanowatts of noise power, in the range of many sensitive applications.
	lfw.pennnet.com /Articles/Article_Display.cfm?Section=Articles&Subsection=Display&ARTICLE_ID=147449 (1803 words)

	5.5 In-orbit Sensitivity of the LWS - Detector Performance (Site not responding. Last check: 2007-10-11)
		To obtain a noise figure 50 minutes of data were taken with the satellite pointing at a dark region of the sky and with a Fabry-Pérot in the beam with its etalons set non-parallel.
		The noise was estimated from the standard deviation of a Gaussian curve fitted to a histogram of the photocurrent values after deglitching.
		The increased NEP was also due to the decreased responsivity which many of the detectors exhibited in-orbit, some of which was due to the decrease in detector bias voltage (to reduce spontaneous spiking) and the effects of ionising radiation on the detectors.
	www.iso.vilspa.esa.es /manuals/HANDBOOK/lws_hb/node31.html (569 words)

	Noise-equivalent power (Site not responding. Last check: 2007-10-11)
		Noise-equivalent power (NEP) is the radiant power that produces a signal-to-noise ratio of unity at the output of a given optical detector at a given data-signaling rate or modulation frequency, operating wavelength, and effective noise bandwidth.
		Therefore, the term is a misnomer, because the units of power are watts.
		The NEP measurement is valid only if the dark-current noise dominates the noise level.
	publicliterature.org /en/wikipedia/n/no/noise_equivalent_power.html (131 words)

	1.6 Optical Detectors and Human Vision (B) (Site not responding. Last check: 2007-10-11)
		Define important detector response characteristics, including responsivity, noise equivalent power, quantum efficiency, detectivity, rise time, and cutoff wavelength for a photon detector.
		Given the necessary information, calculate the noise equivalent power of a detector.
		Given the necessary information, calculate the power reaching a detector after a laser beam is reflected from a Lambertian reflector.
	cord.org /step_online/st1-6/st16b.htm (229 words)

	Glossary Infrared Detectors
		NEP is a function of source temperature, chopping frequency, noise equivalent bandwidth, field of view and background temperature.
		It is expressed, for example, as NEP (500 °K, 1000 Hz, 1 Hz) where 500 °K is the flbody source temperature, 1000 Hz is the chopping frequency and 1 Hz is the noise equivalent bandwidth.
		It is primarily a function of detector area, background temperature, operating temperature, bias, noise equivalent bandwidth and field of view.
	www.calsensors.com /terms1.htm (833 words)

	ESTIMATION OF NOISE EQUIVALENT POWER AND DESIGN ANALYSIS OF AN ANDREEV REFLECTION HOT
		Methods of achievement of the best noise equivalent power of the microbolometer in such version as well as methods of the matching the microbolometer with the incident radiation flow using planar antennas and with the channel of output signal measurement using a SQUID-picoammeter are considered.
		The I-V characteristic and the dependence of the power dissipated in TES on the bias voltage V are shown at Fig.
		Using results of measurements of the current sensitivity and the noise current as well as the estimation of the NEP of the microbolometer with the TES on the basis of the said measurements in [20] and expression (3) one may estimate the NEP of the microbolometer when its demensions are decreased.
	jre.cplire.ru /alt/oct99/2/text.html (4097 words)

	Edmund Optics
		While noise is certainly a key means of characterizing detectors, it is only one of the characteristics which should be considered when selecting a detector.
		The incident light power required to produce a signal on the detector that is equal to the noise.
		In this case, the signal to noise ratio is equal to one.
	www.edmundoptics.com /techSupport/DisplayArticle.cfm?articleid=241 (581 words)

	New England Photoconductor: Terminology
		The amount of required signal radiant power on the detector element area to yield a signal-to-noise ratio of one, and indicates the minimum detectable radiation level; the smaller the NEP value, the better the performance.
		The element of the electrical output (voltage or current) which is incoherent with the signal radiant power, usually measured with no signal radiation incident on the detector element and is related to the detector area.
		It is the function of frequency response, noise equivalent bandwidth, operating temperature, other circuit parameters such as the load resistor, and in some cases detector solid angle and background temperature.
	www.nepcorp.com /info/terms.htm (573 words)

	oe magazine - Test Talk (Site not responding. Last check: 2007-10-11)
		Noise signal in is also called noise equivalent power (NEP, in watts), which is the optical signal in for an output electrical signal-to-noise ratio of 1.
		Noise adds rms; in other words, when it is integrated across the spectrum, the noise is multiplied by the square root of the bandwidth.
		If noise versus frequency is flat (generally true for unbiased photovoltaic devices), then the noise in a 10-Hz bandwidth is √10 times the noise in 1 Hz, and in 100 MHz it is √108—104 times greater.
	oemagazine.com /fromthemagazine/jun04/testtalk.html (700 words)

	2.7 Characteristics of Optical Detectors (Site not responding. Last check: 2007-10-11)
		Detectivity denoted as D* (termed D star) is usually related to the sensitivity, expressed as NEP (noise equivalent power).
		NEP is defined as the signal input identical to the noise output.
		NEP depends on the type of detector, surface of detector or band of frequency.
	www.profc.udec.cl /~gabriel/tutoriales/rsnote/cp2/cp2-7.htm (288 words)

	Calibration & Certification by R. A. Electrical Services
		A unit of energy equivalent to the amount of energy absorbed by one molecule of a material undergoing a photochemical reaction as determined by the Stark-Einstein law.
		The radiant power, at a specified wavelength and band pass that will produce a an output signal from a detector that is equivalent to the inherent noise in that detector.
		An OD of 1 is equivalent to 10% transmission.
	www.raelectrical.com /about_us/light-glossary.htm (3545 words)

	Ambient noise calculator
		The method measures the change in audio output power due to input noise with a change in input attenuation, and given the equivalent noise power of the system components, calculates the external noise power.
		The technique depends on the fact that the audio output power of an SSB receiver is linearly related to the RF input power (including the equivalent internal noise power) up to the onset of AGC action, which is typically more than 20dB above the equivalent input noise power.
		Noise measurements may be entered depending on your selection of "Noise measurement units" on the input form, (consistently) in:
	www.vk1od.net /sc/anc.htm (617 words)

	Hamamatsu Photonics - Europe and America
		Spike noise is a switching noise occurring on the video line via the drain to gate capacitance of the MOS switch when an address pulse is input.
		When the fixed pattern noise is subtracted by an external circuit, random noise determines the lower limit of light detection of the image sensor, or the lower limit of dynamic range.
		Noise in photodiodes is the sum of the thermal noise (or Johnson noise) ij of a the shunt resistance and the shot noise isD and isL resulting from the dark current and the photocurrent."
	sales.hamamatsu.com /de/support/glossar.php?&item=13186785 (606 words)

	[No title]
		A detector is referred to as BLIP (background limited) when its D* is limited by the noise associated with photons from the background radiation and not by intrinsic detector noise.
		The radiant power that produces a signal-to-noise ratio of one at the output of the detector.
		RD is the slope, dV/dl, of the current-voltage curve at zero-volt bias.
	judsontechnologies.com /Glossary.htm (420 words)

	oe magazine - tutorial - photodiodes see the light (Site not responding. Last check: 2007-10-11)
		Photodiode sensitivity is very important in low-light applications and is typically quantified by noise equivalent power (NEP), defined as the optical power that produces a signal-to-noise ratio of unity at the detector output.
		NEP is usually specified at a given wavelength and over a frequency bandwidth of 1 Hz and is therefore expressed in units of W/Hz Because the various performance parameters are interrelated, device design often involves careful tradeoffs to achieve optimum performance.
		In more complex devices, the various noise sources (shot noise, Johnson noise, and 1/f noise) can be represented as additional current sources in parallel to the signal current source.
	oemagazine.com /fromTheMagazine/aug01/tutorial.html (1596 words)

	OSI Optoelectronics Technical Support FAQ Noise and lower limit of detectivity
		The Noise Equivalent Power or NEP, is the incident optical power, which generates a photocurrent equal to the noise of the photodiode.
		Pn the photovoltaic mode measurements, the limiting source of noise is the Johnson (or thermal) noise in the source or shunt resistance.
		Noise is the random electrical signal that interferes with the measurement of the signal of interest.
	www.udt.com /techsupport_faq08.html (397 words)

	ECE 397 Lab 5: Detectors
		The absorbed power affects the detecting medium by altering its chemical or physical state or by causing charge to flow through it.
		In imaging detectors, the primary noise sources are counting fluctuations or "shot" noise and dark current or "thermal" noise.
		All of the detectors we have discussed are "square law detectors." The output is not proportional to the optical electric field, rather the output is proportional to the power intensity, which is proportional to the square of the field.
	www.disp.duke.edu /~dbrady/ece371/notes/detectors (742 words)

	Support - FAQs (Site not responding. Last check: 2007-10-11)
		The minimum detectable optical power (Pmin) is a function of wavelength (l), measurement bandwidth (B), and noise-equivalent power (NEP).
		For these models, the output voltage versus input laser power is calculated from the equation Vout=Pin·G·R, where Vout is the output voltage, Pin is the input optical power in mW, G is the gain factor (determined by the setting of the gain knobs and switches), and R is the response factor in volts/mW.
		Common-mode noise that is present on both the reference and signal beams (such as laser-intensity noise) is cancelled out and thus doesn't appear as part of the signal.
	www.newfocus.com /support/faqs/detectors_faqs.cfm (5331 words)

	TIFT (Site not responding. Last check: 2007-10-11)
		The size, weight, and electrical power requirements will be consistent with portability.
		The Phase I effort will be focused on the demonstration of revolutionary component and integration technologies necessary for the development of a diffraction-limited, video-rate THz frequency imaging imager.
		One objective will be the demonstration of a compact THz source achieving at least 10 mW of average power and 1% wallplug efficiency, as required for active illumination and/or for local oscillators in heterodyne or homodyne detection schemes.
	www.darpa.mil /mto/tift (197 words)

	Pyroelectric Power and Energy Meter
		To measure CW (Continuous Wave) power, the P-444 Probe is used in conjunction with the PH-30 Power Head.
		The PH-30 power head serves to convert the incoming beam into a series of precisely timed pulses that are subsequently measured by the P-444 Probe and computed in terms of power.
		The vast majority of the input power is channelled into a beam dump in the power head and does not contribute to detector heating.
	www.laser2000.co.uk /lasers/measure/radio.htm (554 words)

	Germanium Detectors
		J16Si Series detectors are ideal for optic power measurements that need to differentiate between 800 nm and either 1300 nm or 1550 nm.
		When used in environments where vibration is present, the microphonic noise from the dewar leads may dominate the detector noise.
		Care must be taken with external connections to avoid noise from vibrations outside the dewar.
	www.judsontechnologies.com /germanium.htm (1914 words)

	Radar Systems
		This directly equates the noise to a detected power level so that it may be compared to the return.
		Random events like noise will not occur in every pulse and therefore, when averaged, will have a reduced effect as compared to actual targets that will be in every pulse.
		The peak power and the average power are related by the quantity called duty cycle, DC.
	www.fas.org /man/dod-101/navy/docs/es310/radarsys/radarsys.htm (3042 words)

	1. Calorimeters with Resistive Thermometers
		This negative electrothermal feedback tends to return the calorimeter to the base temperature as the thermal energy deposited by the X-ray photon is compensated for by a drop in Joule heating.
		If noise from the amplifier and load resistor are neglected the square of the noise equivalent power has two parts:
		is due to Johnson noise and P is the dc power dissipated in the thermometer.
	lheawww.gsfc.nasa.gov /users/audley/diss/node33.html (700 words)

	RADAR BASICS
		The transmitted power Pt, at a range R from the transmitter, is homogeneously spread over the surface of a sphere of radius R, with a power density:
		A target having 1m^2 cross-section reflects toward the radar a power equivalent to all the power impinging on a surface of 1m^2 radiated isotropically (the physical area of the target may be smaller than its cross-section if it re-radiates preferentially toward the radar).
		It is important to remark that the receiver noise is proportionally to its bandwidth: this is also intuitive, being the thermal noise "white", i.e.
	www.alphalpha.org /radar/intro_e.html (2396 words)

	Stereophile: Halcro dm88 Reference monoblock power amplifier
		Output power: >270W into 8 ohms, >500W into 4 ohms.
		Intermodulation products: all <–126dB relative to power output for sum of 19+20kHz tones, each delivering 100W into 4 ohms, or at peak power.
		Noise: equivalent input noise at the input is 5nV/sqrt(Hz) in voltage mode, 6pV(Hz) in current mode.
	www.stereophile.com /solidpoweramps/806halcro/index2.html (334 words)

	SDL / Conferences / Calibration Conference
		However, if the noise-equivalent power or the noise-equivalent irradiance of the sensors can be decreased, then short-wave infrared (SWIR) detectors can be used for such applications, leading to numerous advantages in the laboratory and in the field.
		Since the SWIR sensors do not operate in a background-noise-limited mode, the dominating sensor noise originates from the 1/f noise of the preamplifier and the resistor noise, which is dominated by the detector shunt resistance.
		Ribbon sources are lightweight and draw power only for only a few seconds as needed, and they can be quickly switched from one radiometric level to another to cover the sensor's dynamic range.
	www.sdl.usu.edu /conferences/calcon/abstracts/critical-calibrations (1445 words)

	ISOPHOT_OBSERVER's_MANUAL: Photometric Sensitivities (Site not responding. Last check: 2007-10-11)
		P is the power illuminated on the detector and depends on the measurement mode and the flux of the source.
		is the noise equivalent power determined as the total of all noise source contributions along the signal chain.
		In the individual AOT sections in Chapter 6 the total power P and the different noise sources contributing to
	www.ipac.caltech.edu /iso/isomirror/manuals/iso_pht/node31.html (209 words)

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