What is the significance of 3-db bw?

[venkateshr]

what is the significance of 3-db bw. i know much about that but dont know why all insist on that rather than say 0-db bw.

is that due to consitent gain or phase diff.

plz explain me

 

[IanP]

Re: 3-db bw

The conversion for decibels is often simplified to: "+3 dB means two times the power and 1.414 times the voltage"

See section "-3dB ≈ ½power" at:
https://en.wikipedia.org/wiki/Decibel

Regards,
IanP

 

[venkateshr]

Re: 3-db bw

thanks Ian. i know how the 3db comes and what the output res. wil be and the load impedance will be equal to output reasistance. all i know but i dont know why we insist on 3-db bw.
is that bbecause we want freq. reponse devoid of any pole

 

[IanP]

Re: 3-db bw

"3dB or Knee Frequency"
https://www.freelists.org/archives/si-list/06-2002/msg00088.html
This one adds a couple of interesting oppinions on this issue ..


Regards,
IanP