You Have not specified requirements for your "noise filter". Answer can be only general. Filter can be any of standard filter types, low pass, highpass, bandpass or band reject. There is no rule what type "noise filter" should be.
Some books about the filter design introduce more informations about the spec.and type abput LP,HP,BP and stop pass.Also you can use some simulator to
get the result directly.
fhl said:
ok...thanks...
then...could anyone tell me the types of the noise filter...any related info etc...tq