what's "prewarping technique"

[skythunder]

prewarping

Hi,

I am wondering how "prewarping technique" is used in active filter design to fix gain lossy or realize an exact filter transfer function H(z). Especially in switched capacitor filters.

Can someone please explain this technique in detail or recommend some related papers for reference ?

Thanks in advance

 

[panditabupesh]

prewarping for discrete filters

Hello
Look at the bilinear transformation- used to convert from a continuous function to a discrete transfer function. Warping is a part of this transformation, and prewarping is trying to negate like tan^-1(tan wc)) = wc.

Bupesh

 

[skythunder]

bilinear transform prewarping

Thanks for your answer, Bupesh.

Sometimes the signal gain with frequency of interest is attenuated when passing the filter, which is not desirable. Therefore some books say that prewaring technique can be used to stop this. I want to know how this technique works on this purpose ? can you please provide an example or something convincing ?

Thanks !