Questions tagged [signal-to-noise]
The signal-to-noise tag has no usage guidance.
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How can I improve "SNR" in a measurement of noise power?
I'm doing an experiment where I need to use a shot-noise tunnel junction as a calibrated noise source to characterize our measurement system. This is done by sweeping the voltage across the SNTJ and ...
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Simulate different grounds with noise in LTSpice?
Is there any way to split 2 different grounds in LTSpice?
What my aim is to observe the optocoupler input side called "GND-D" and collector output side that called "GND-A"; I want ...
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How did old mobile phones amplify signals lower than the noise floor?
In the early days of GSM in around 2000 when the network was still not fully deployed, it was common for me to receive very low signal, even sometimes No Signal due to out of network.
I used to use a ...
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How can I determine the dimensions of a spiral trace on a PCB?
I was designing a circuit that contains some analog signals along with signals of relatively low frequency (2.5 kHz) and I was reading a bit about norms, standards, and good practices for the design ...
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How to calculate combined interference power from different jammers?
Let's say I have a communication system. The transmitter transmits the signal S (the wanted signal). The power of signal S at the receiver is W1 (in watt).
When we connect a spectrum analyzer at the ...
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How to extract ENOB from LTSpice simulation and see the effects of oversampling?
I have a fully differential instrumentation amplifier circuit with a gain of 536 to map a 3mVpp signal (centred around 1.65V) to +/-1.6V, as shown here.
My signal bandwidth is 250Hz, and I would like ...
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Averaging time, T, of analog lock-in amp equivalent in digital lock-in amplifier
My understanding of lock-in used to be only that of an analog lock-in amplifier.
Now, I am thinking about digital lock-in technique.
Reading this has been helpful.
However, I am having trouble ...
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Step by step calculation of noise factor does not match the overall system calculation
I know this is a very stupid question but I've been trying for a couple of days now to figure out what mistake I'm doing.
I have two cascaded blocks as following:
Block one is an amplifier with:
Gain (...
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Best way to transfer indication signal from one STM32 to another STM32 [closed]
This is the system:
I need a simple way to pass a signal from the upper controller to the lower controller.
The whole purpose is to read an analog voltage, sample it, make statistics, and transfer to ...
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Derivation of attenuator noise factor as a function of its physical temperature
I have been struggling for the past few days with the noise analysis of an attenuator of attenuation \$l\$, at a temperature \$T_A\$, connected to a source with input noise temperature \$T_0\neq T_A\$....
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How to eliminate the noise of this circuit?
I've built the following circuit on a PCB with reference to a TI's solution.
I changed the gain of the INA to 10 and the gain of the A3 stage to 40. I also changed the cut-off frequency of the A4 ...
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Does placing two optocoupler one below another in PCB design affect any signal?
I am working on a circuit where I am using multiple ultrasonic sensors which work on 24V, to read the sensor output through a microcontroller that accepts 5V. I am using optocoupler PC817 to maintain ...
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RF channel noise interference calculation
I am trying to calculate how far a co-channel or noise source has to be from the primary channel, in this case a WiFi channel, for it not to interfere with the link performance.
This question takes ...
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How to determine noise power and SNR from extinction ratio?
I have a pulse train signal with infinite extinction ratio (ER). I want to add a white gaussian noise to my signal to get ER=15 (dB). I know that ER=P1/P0, i.e., the power level with the light source ...
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ATmega analog comparator generates spurious interrupts
I'm experimenting with the comparator inside a ATmega328 to see if it can be used for zero detection of a DC 2.5V superimposed AC signal monitored on one of the ADC inputs.
I use the code as shown ...
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Potentiometer ADC noise varies based on position of wiper?
I have a potentiometer setup as a voltage divider like so, where the wiper of the potentiometer gets fed into my MCUs ADC Pin:
When I measure the noise of the incoming ADC signal, I get different ...
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Acceptable SNR for a Sound Level Meter
I'm designing a low power (<150mW) sound level meter (SLM) using a 24bit ADC (preliminarily using the LTC2512-24). This is for audible frequency range signals only (20Hz - 20kHz). I'm focused on ...
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Can an LNA noise figure be normalized to dBm to estimate the minimum detectable signal?
If a device claims a noise figure of 0.3 dB NF such as the Qorvo QPL9547, can you calculate the dBm value of a signal that is at the noise floor (ie, a barely detectable signal)?
Otherwise stated: I ...
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Signal to Noise Ratio Vs Signal to Distortion Ratio
I am a bit new to this field and I was reviewing some speech enhancement papers. These two terms keep popping up every once in a while so I was very confused as to what the difference between these ...
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Estimating shot noise - what's the origin?
If I have some photon detector, say a CCD, how do I estimate the error introduced by shot noise correctly? Typically, sources found on the internet say that the shot noise is the square root of the ...
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Consider Noise in Link Budgets
I want to verify the range of my RF-system for a university project.
I use two transceivers (Datasheet) and one power amplifier on the transmit side (Datasheet). The target range is 120 km over which ...
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Noise Figure of an Attenuator
it is known that the noise figure of an attenuator is equal to its attenuation coefficient L. A proof of this statement is provided here.
Basically, it uses the formula (Reference):
$$F = 1 + \frac{...
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Build a Radiated EMI Generator
I'm building a radiated noise generator. My intention is to expose my developed equipment to electromagnetic noise. I want to check the behavior of the equipment in noisy situations.
So I want to ...
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Can I connect GNDD with GND to get stable result?
I am using JY-S60 Signal conditioner (SC) (click here to see datasheet, giving amazon link, could not find specific link for datasheet) with small load cell click to see load cell datasheet. I have ...
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Amplitude Spectral Density from a Fast Fourier Transformation
I want to calculate the Noise-equivalent Power (NEP) of a photodetector.
Hereto, I have to measure the Amplitude Spectral Density (ASD) of the detector and divide the result by the Responsivity:
The ...
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S/N ratio or distortion analyzer
I'm having trouble finding an affordable low bandwidth analyzer solution for measuring audio spectrum performance (20KHz and below). Does anyone have a suggestion for buying (new / used) or building ...
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737
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Noise figure calculation in LTspice
I am a newbie in LTspice so the question can be seemed to be bit stupid, but I have build an LNA and now I want to calculate the noise figure of the system. I have run the .noise statement to ...
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What is the derivation of the Shannon-Hartley theorem? [closed]
I know by Hartley's theorem that information is proportional to bandwidth and time. The capacity corresponds to information and bandwidth is there. I don't get how the logarithmic part corresponds to ...
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In noise voltage equivalent circuit, why are the source and load resistances equal?
Yes I am aware of the maximum power transfer theorem. I don't get though what the lesson meant, especially by worst condition.
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Signal averaging CCD
I'm thinking about signal to noise ratio of CCDs and I hope this is the right location to post my question. The Hamamatsu Learning Center seems to be a good starting point to learn about CCDs. I ...
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Noise equivalent power of thermopile sensor?
I am working on the characterisation of thermopile sensor and stuck in determining the NEP of the sensor.
My thermopile sensor with AD8630 amplifier receives IR radiation coming from the blackbody at ...
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How exactly does the low-pass filtering in a lock-in amplifier correspond to a time-averaging?
In this white paper of Zurich instruments two ways of explaining a lock-in amplifier are shown: low-pass filtering and time-averaging. Whereas the explanation with time-averaging can easily be done ...
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Advice on Noise in Square Input Signal
I am reading the following signal from an open drain output, and trying to read the signal frequency. However, I am getting short spikes in the wave as seen below, and this is messing with the reading ...
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Maximizing signal to noise ratio for very small radiation detector
I have a very small radiation detector that outputs signal of small amplitude. Requires preamplification before going to an actual amplifier. When constructing the system prior to the preamp, would I ...
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Does "a signal is buried in noise" mean that the noise amplitude is still smaller than the signal amplitude? (Special case: Lock-in amplification)
I heard that Lock-in amplifiers (LIAs) especially play to their strengths when the signals are weak compared to the noise level. But then I talked with someone about it, who understands the principles ...
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Producing simulated thermal noise
I’m trying to simulate thermal (Johnson) noise. As I understand it, thermal noise follows a Gaussian distribution, power at the receiver is given by:
$$
P = 4kTB
$$
And the RMS voltage is given by:
$$
...
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How to calculate noise voltage after amplification?
I'm simulating the thermal noise experienced by some instrument, outputted as a voltage vs time plot. To calculate the "power" of this noise, I'm using:
P = 4kTB (k = Boltzmann's constant, T ...
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How to calculate thermal noise contributed by an LNA?
I've written a thermal noise simulation for a piece of equipment which produces the oscilloscope trace one would expect to see coming out of the instrument.
Now, I'd like to take into consideration ...
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How to plot thermal noise in the time domain?
The power of this thermal noise is given by:
P = 4kT (k = Boltzmann’s constant, T = temperature (Kelvins))
And, thus, the voltage by:
V^2 / R = 4kT (R = resistance)
Finally, we must take into account ...
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Do parallel LNAs at 90-degrees to eachother reduce the noise floor more than side-by-side?
Wiring amplifiers in parallel in a summing configuration improves the signal to noise ratio because amplifier noise in each LNA is uncorrulated. However, external noise sources will still be a factor ...
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How does wiring two LNAs in parallel affect charactaristic impedance?
It appears that wiring amplifiers in parallel improves the signal to noise ratio. I thought I would experiment with two SAV-541+ LNAs in parallel and see how they perform:
How does wiring an LNA in ...
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Charge, Voltage, or Current? What can be measured with the highest SNR?
Suppose I have a Faraday cup and a certain number of ions hit the detector. What is the highest signal to noise ratio way / circuit to measure this... does one measure the charge (coulombmeter), ...
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Signal to noise in relationship with limit of detection and/or signal strength
I wonder about the following:
The limit of detection is given as being 3 sigma of the blank peak away from the blank signal (which is noise finally, I think?).
What struggles me is: In my head this is ...
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Regarding signal to noise ratio
I had set up multiple receivers and I was recording the same signal on all of them. I then stacked all of these signals. I have read that to improve the signal to noise ratio, mean and median of this ...
user251498
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Noisy output on voltage reference and correct probing
I'm building a circuit that has a 2.5V Voltage reference for use on the internal ADC of a STM32F7 in 12 bit mode. As each bit corresponds to 610uV I'd like to have as little noise in the signal as ...
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Would submerging a 100% waterproof hotspot device increase network connectivity?
I have this portable hotspot device (9cm*6cm*1cm*) in which I insert a simcard and keep it within 10m when I am using it. Let us consider that it is water cannot damage it even if I submerge it. Would ...
user247445
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Detection of signals buried in noise
This is more of a general question to see which methods are the most common to improve the detection of a signal which is buried in noise. Currently, we are building an optical system for medical ...
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Noise Floor of ADC using PWELCH
While using MATLAB's Pwelch function, I am not able to match the noise floor of the "Modelled" ADC to (Delta)^2/6 {1 sided Spectrum}.
...
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What is the math behind high FM frequency components being more noise prone? [closed]
what is the math behind the phenomena that higher frequencies are more prone to noise?
The use of pre-emphasis to boost the higher frequency components to get a better S/N ratio.
Can you provide ...
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Problem in deriving Noise Figure for Cascaded systems
I am trying to derive Noise Figure of Cascaded System. I am making some conceptual mistake somewhere in derivation and getting wrong answer. Can any one please help me figure out where I am going ...
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