Electrical Engineering Stack Exchange
Electrical Engineering Stack Exchange

Questions tagged [aliasing]

44 questions
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Why does increasing the sampling rate make implementing an anti-aliasing filter easier?

From an answer to a question regarding sampling rate and anti-aliasing filter I read the following: The closer you get to the theoretical minimum sample rate, the more difficult the analog filter become to realize practically. If I'm not…
user1245
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Divider and lowpass combined

I am using the following circuit for two purposes: As a voltage divider, to reduce DC sensor output to a range suitable for my ADC. As a lowpass filter, to remove high frequency noise from the signal. It works great, but my choice of component…
Jeremiah Rose
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Measuring low-duty-cycle supply current

I am trying to measure average current draw of low-duty cycle, low current devices. For example, a Bluetooth Low-Energy device might draw 16 mA during the radio transmissions (for a millisecond or so), and background / idle current at other times,…
markrages
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Anti-Aliasing filter design

I appreciate that different applications have different criteria, but could someone give a ball park figure of how much attenuation is needed for an anti aliasing filter at the Nyquist frequency to prevent aliasing? For example I'm building a filter…
genericpurpleturtle
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Recording aliased tones on purpose

For research purposes, I am trying to transmit a tone and record it using sub-Nyquist sampling. Via the PC microphone, for instance, I would expect to see the aliasing effect somewhere in the spectrum plot, but no matter what I try it is absent. I…
Dannynis
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How to remove aliasing effects?

I collected data in the time domain and then calculated the FFT to see how it looks in the frequency domain. Since the signal isn't band-limited, I think I have aliasing and there are features at high frequencies that don't make physical sense to…
user2561523
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what is memory aliasing?

I was reading about ARM M series and somewhere it was written that: "the flash memory area is aliased from address 0x0000 0000". what does it mean?
Brijesh
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Aliasing vs Imaging. What is imaging?

In DSP for audio, I understand what Aliasing is (fixed with an anti-aliasing filter), but there is also something called Imaging (fixed with a reconstruction filter). Aliasing is when a higher frequency mirrors DOWN about 1/2 the Nyquist frequency,…
Sajeev Ranasinghe
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Adding anti-aliasing filter to op-amp before ADC, clock frequency or sampling frequency?

I am designing an anti-aliasing filter for an MCP3202 ADC. I'm kind of confused by defining my corner frequency Fc, I'm working with a 60 Hz input signal with harmonics until around 3 kHz that comes from an air conditioner current signal, so I can…
joshua andres blanco jerez
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DAC "aliasing" of harmonics

While reading articles and application notes regarding DACs and their output spectrum, I stumbled across aliasing of higher harmonics to the first Nyquist band. For example, when generating a single test tone with a DAC, harmonics of the fundemental…
t_nogic
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Is using passive anti-aliasing filter with its transfer function instead of an active filter common or reliable?

I need to ask this general question with an example for clarity. Imagine I have to measure a signal with BW of 5kHz and I need to make a unity gain active anti-aliasing filter with a steep roll off where the stop band is required to be -60dB at…
user1245
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ADC anti-aliasing filter

I bought a 16bit, 250kSPS AD7689 ADC. The circuit I am designing will amplify voltage (from 300uV up to 300mV) across a current-sense resistor (by 13x) to match 4.096V reference and feed this into an ADC. Measured voltage will either be DC or <1kHz…
Golaž
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Nyquist frequency mirroring

I need someone to check my understanding of Nyquist frequency. I understand it in the following manner. $$F_{nyquist} = ( F_{sampling}/2 ) * n$$ where n is an integer (negative and positive). For instance: $$ F_{sampling} = 10 kHz $$ then…
Martin G
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How to measure energy distribution

I want to evaluate the energy flow in a battery powered system. So when the system runs a specific task the energy distribution between the different loads can be obtained ( similar to a Sankey diagram). For this a timescale in the range of…
Grebu
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How to design anti-aliasing filter for a non-ideal oversampled SAR

If we want to go by text-book anti-aliasing filter design for an ADC, we would have \$A(f_{samp}/2)\ge-20*log(2)*N\$ dB attenuation at the Nyquist frequency, where \$A(f)\$ is the magnitude vs frequency function, \$f_{samp}\$ is the sampling…
davidanderle
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