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Specifications of Band pass filter

Started by arur...@yahoo.co.in December 5, 2006
hi every body,

i am implementing a Band pass FIR filter,my centre freq is 5k and by band of interest is 2.5k to 7.5k.My doubt is how to make decission on passband freq1,passband freq2,stopbandfreq1,stopbandfreq2.
please let me know.
Obviously your passband and stopband frequencies should be
around your band edge. The filter design program tries, in
general, to make the passband response flat, and the
stopband response zero. The region in between is not
constrained. This forms the "band edge" where the response
transitions from 1 to 0.

So if you specify passband and stopband frequencies close
together, the band edge would be steep. This is usually
desirable. However, you usually pay a price with passband
ripples, phase inaccuracy, or stopband side lobes. The
tradeoff depends on the type of filter used, and the filter
length.

Therefore, how to specify passband and stopband depends on
the requirements of your problem: how steep you need on the
band edge, and how much ripple you can tolerate in passband,
etc. Once you are clear on the requirements, you can
experiment with different settings to get an optimal design.

Hope it helps.

Feng

_____

From: m... [mailto:m...]
On Behalf Of a...@yahoo.co.in
Sent: Tuesday, December 05, 2006 7:45 AM
To: m...
Subject: [matlab] Specifications of Band pass filter

hi every body,

i am implementing a Band pass FIR filter,my centre freq is
5k and by band of interest is 2.5k to 7.5k.My doubt is how
to make decission on passband freq1,passband
freq2,stopbandfreq1,stopbandfreq2.
please let me know.
refer to fdatool for graphical illustration
sivakanth

a...@yahoo.co.in wrote: hi every body,

i am implementing a Band pass FIR filter,my centre freq is 5k and by band of interest is 2.5k to 7.5k.My doubt is how to make decission on passband freq1,passband freq2,stopbandfreq1,stopbandfreq2.
please let me know.