Band Pass Equiripple Filter 2.

Cuthbert Nyack
Band pass FIR filters with lenghts up to 135 can be derived with the applet below.
Scrollbars 0 to 68 are used to move the frequency extrema.
Scrollbars 69, 70 and 71 set the number of extrema.
Scrollbars 72 and 74 set the pass band and stop band edges.
Scrollbars 73 and 75 set the transition band widths.
Scrollbars 76 and 77 set the ripple ratio and grid density.
Scrollbars 78 and 79 move the White and Blue frequency reference lines.
Scrollbars 80 and 81 set the dB/div and the dB of the dark red reference line.
Scrollbar 82 sets the error gain.




In the case below, the transition bandwidth is 0.05ws and the stop band attenuation is greater than 102dB.

In the case below, the transition bandwidth is 0.05ws and the stop band attenuation is greater than 100dB, this time with a narrower pass band.

In the case below, one transition bandwidth is 0.04ws and the second transition bandwidth is 0.05ws. The stop band attenuation is greater than 87dB.
In this case a 'notch' appears in the wider transition band.

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COPYRIGHT 2008 Cuthbert Nyack.