Range of sampling frequencies for an analog signal < 10kH

[the_jackal]

Analog signal < 10kHz

An analog signal contains frequencies up to 10kHz. What range of sampling frequencies allows exact reconstruction of this signal from its sample?

 

[arturt134]

Re: Analog signal < 10kHz

There is Nyquist law: sampling frequency should be twice signal frequency to exact rebuild sampled signal.
Practically, for better performance, for signal 10kHz use sampling frequency bigger than 20kHz, maybe 25-30kHz.

 

[picus]

Re: Analog signal < 10kHz

Ok for Nyquist but you can use a prefilter first.


i.e.
-------------------- ----------------
---- | low pass filter | ---- > --- | ADC conv. | ---->----
-------------------- ----------------

 

[Circuit_seller]

Re: Analog signal < 10kHz

Hi

It is completly depends on your dynamic range and antialiasing filter sharpness. more dynamic range( number of ADC bit) requires either shaper antialaising filter or more sampling rate.

Regards

 

[v_naren]

Re: Analog signal < 10kHz

the ideal sampling freqyency will be 20KHz if there is an ideal low pass filter

 

[IanP]

Re: Analog signal < 10kHz

Exact reconstruction will occure if you have infinite number of samples.
This business with Nyquist criterion only gives us the minimum frequency (2 x Max frequency in original) at which you will be able to "follow" the original.
In practice, if you want the reconstraction to be of good quality take as many samples as you can .. obviously be reasonable and don't exaggerate.
I think in your case of 10kHz something close to 100ks/s will give you quite good copy.

 

[machael]

Analog signal < 10kHz

Theoretically, 20kHz is enough.
However, in practical , you 'd better use a sample rate above 20kHz. 30~40kHz is enough.

 

[Circuit_seller]

Re: Analog signal < 10kHz

Hi

I think the sampling rate depends on the "tolerable aliasing", "tolerable distortion" and dynamic range of the ADC.
We can not advise him/her to take a sampling frequency and we do not know the specifications.

Regards