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Message ID: 11421     Entry time: Thu Jul 16 16:33:56 2015
Author: Jessica 
Type: Update 
Category: General 
Subject: Added Bode Plots of Bandpass Filter 

I updated the bandpass filter I was using, finding that having different stopband attenuations before and after the passband better emphasized the area from 3 Hz to 20 Hz. I chose a low passband ripple but high stopband attenuation to do this. My passband ripple was 2 dB, the first stopband was 25 dB, and the second stopband attenuation was 40 dB. As can be seen in the filter Magnitude plot, this resulted in a fairly smooth passband and a fairly step dropoff to the stopband, which will better emphasize the region I am trying to isolate. My goal was to emphasize the 3-20 Hz region 10-30 times more than the outside regions. I think I accomplished this by looking at the Bode plot, but I may have chosen the second stopband attenuation to be slightly too high for this. 

Attachment 1: acc1_update.png  175 kB  | Hide | Hide all
Attachment 2: acc2_update.png  180 kB  | Hide | Hide all
Attachment 3: acc3_update.png  171 kB  | Hide | Hide all
Attachment 4: bp_BodeMag.png  100 kB  | Hide | Hide all
Attachment 5: bp_BodePhase.png  70 kB  | Hide | Hide all
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