application of active bandpass filter

H

Thread Starter

hytee

Joined Mar 31, 2009

3

Mar 31, 2009

• #1

Hi, cloud anybody tell me about the application of active bandpass filter which has lower and upper cutoff frequency at 300HZ and 3000HZ respectively in our real life?
Thank.(urgent)

 

Last edited: Mar 31, 2009

t_n_k

Joined Mar 6, 2009

5,455

Mar 31, 2009

• #2

Do you want to know about the specific application of a filter with these characteristics or do you want to gain an understanding of how to design such a filter?

Suggestions:

Google "active bandpass filter design" ...etc

If you are interested in the circuit designs & simulation then you could try this free down-loadable filter design program....

http://focus.ti.com/docs/toolsw/folders/print/filterpro.html

or this on-line design tool ....

http://www.analog.com/en/design-too...ign-sim-tool/Filter_Wizard/resources/fca.html

 

flat5

Joined Nov 13, 2008

403

Mar 31, 2009

• #3

One such use would be a radio play in which you need the sound of someone talking on the telephone.

 

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Darren Holdstock

Joined Feb 10, 2009

262

Mar 31, 2009

• #4

Sounds like something bandwidth limited for speech - most likely a telephone or an intercom. Most common bandpass filters are restricted to f_high < 2f_low (very roughly), so it would be usual to make this bandpass filter from a highpass followed by a lowpass.

 

H

Thread Starter

hytee

Joined Mar 31, 2009

3

Mar 31, 2009

• #5

Hi, Thanks a lot for your guys' suggestions. Actually i want to know about the specific application of bandpass filter (active or passive) with these kind of characteristics. Cloud u help me? thanks

 

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Darren Holdstock

Joined Feb 10, 2009

262

Apr 1, 2009

• #6

hytee, I think you need to ask the question in a different way; it's not clear what you need. It's just a language barrier - your English is better than my Malaysian. Are you asking whether a passive or active filter is best for the job, or are you looking for working circuits?

 

gotumal

Joined Mar 24, 2008

99

Apr 1, 2009

• #7

The application is in the telephony, or any voice network. Since the vocal frequencies lie between 0.3. to 3.4kHz, these filters are used to remove unwanted noise.

P.S. This question was asked for my viva, and I answered correct!

 

KL7AJ

Joined Nov 4, 2008

2,229

Apr 1, 2009

• #8

That would be the audio bandwidth of a typical single sideband transmitter as well. (Which translates to the same R.F. bandwidth, if everything is working as it should. )

 

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RAH1379

Joined Dec 13, 2005

69

Apr 14, 2009

• #9

hytee said:

Hi, cloud anybody tell me about the application of active bandpass filter which has lower and upper cutoff frequency at 300HZ and 3000HZ respectively in our real life?
Thank.(urgent)

Click to expand...

Those frequencies are where most of the information is contained in the human voice, the filter will let the voice through while stopping other noise with higher or lower frequencies. it is a common filter used in voice communications.