karthick121 wrote:
> hi all,
> i am wondering about how to sample for a high pass digital filter
> which has a high bandwidth. Because according to Nyquist theorem 
> it should be more than two times the bandwidth of the high pass filter. so
> how it can be achieved with the limited ADC resolution that practically we
> have?

You left something out of your question and out of your thought process. 
A digital signal always has an upper frequency limit of no more than 
twice the sample rate. If the signal fed to the ADC contains frequencies 
hither than that, they will be aliased below that, thereby corrupting 
the sampled signal. The usual practice places a low-pass analog filter 
just ahead of the sampler in order to avoid aliasing. The question that 
seems to trouble you doesn't actually arise.

Jerry
-- 
Engineering is the art of making what you want from things you can get.
¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯

karthick121 wrote:

> i am wondering about how to sample for a high pass digital filter
> which has a high bandwidth. Because according to Nyquist theorem 
> it should be more than two times the bandwidth of the high pass filter. so
> how it can be achieved with the limited ADC resolution that practically we
> have?

You question is a little confusing.

Consider CDs sampled at 44.1kHz.  That theoretically allows (unaliased) 
frequencies up to 22.05kHz.  That a high pass filter can't have a 
passband bandwidth higher than 22.05kHz seems sort of obvious.

Can you explain more what you are trying to do?

-- glen

hi all,
i am wondering about how to sample for a high pass digital filter
which has a high bandwidth. Because according to Nyquist theorem 
it should be more than two times the bandwidth of the high pass filter. so
how it can be achieved with the limited ADC resolution that practically we
have?
please reply 
thanks