Ye
Newbie level 3
![Newbie level 3](/styles/images/ranks/alevel3.gif)
I am trying with a linear phase bandpass filter for wideband application(about 400MHz@1.25GHz). And the group-delay turns out no longer flat because of the nonlinearity while doing the lowpass to bandpass transform(i am using Lancast's lowpass prototype). Now i've found out Rhodes developed in his paper"Cascade Synthesis of Selective Linear Phase Filters(CT-19,1972)" a so-called"hyperbolic group delay prototype" to overcome the problem.
However there is no way i can get the right values for the lowpass prototype elements by his formulars and i am not sure where is wrong.
Is there anybody ever tried that kind of filters? Or there is some other to develop the broadband bandpass filter? Please help me out...
Regards
However there is no way i can get the right values for the lowpass prototype elements by his formulars and i am not sure where is wrong.
Is there anybody ever tried that kind of filters? Or there is some other to develop the broadband bandpass filter? Please help me out...
Regards