Author Topic: The Biquadratic filter  (Read 949 times)

0 Members and 1 Guest are viewing this topic.

Offline promachTopic starter

  • Frequent Contributor
  • **
  • Posts: 878
  • Country: us
The Biquadratic filter
« on: July 06, 2018, 02:34:03 pm »
I am reading an article on biquadratic filter. The article is attached in this post

How do we derive corner frequency equation (6) on page 2 ?

Does it have to do with equation (5) ?
 

Offline JS

  • Frequent Contributor
  • **
  • Posts: 947
  • Country: ar
Re: The Biquadratic filter
« Reply #1 on: July 06, 2018, 09:54:39 pm »
Make the |H(jw)|=-3dB or (6)=0.5, which is the same. Find for which frequencies that's true, build (6) from there.

Algebra can be quite confussing for this things, mostly because is not that you are after an answer but the shape of the equation, to be easy to read, so some variable manipulation is needed, not just moving around stuff.

JS
If I don't know how it works, I prefer not to turn it on.
 

Offline The Electrician

  • Frequent Contributor
  • **
  • Posts: 747
  • Country: us
Re: The Biquadratic filter
« Reply #2 on: July 06, 2018, 11:37:52 pm »
Set the right side of (5) equal to .5 and solve for omega:

 
The following users thanked this post: promach


Share me

Digg  Facebook  SlashDot  Delicious  Technorati  Twitter  Google  Yahoo
Smf