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Entry  Wed Feb 1 15:46:51 2012, tara, DailyProgress, Electronics Equipment, acav characterization inloop.pngnb_2012_02_01.pnginputrange.pngACAVOLGTF.png
    Reply  Thu Feb 2 23:51:32 2012, frank, tara, DailyProgress, Electronics Equipment, acav characterization 2012_02_02_block.png2012_02_02_pll.pngmarconi_TF.png
       Reply  Sat Feb 4 03:18:08 2012, tara, DailyProgress, Electronics Equipment, acav characterization 2012_02_03_pll.pngPLL_TF.png
          Reply  Mon Feb 6 22:35:49 2012, frank, tara, DailyProgress, Electronics Equipment, acav characterization TF.png
Message ID: 810     Entry time: Sat Feb 4 03:18:08 2012     In reply to: 809     Reply to this: 811
Author: tara 
Type: DailyProgress 
Category: Electronics Equipment 
Subject: acav characterization 

I checked the TF of the amplifier used in the ACAV loop because I did not measure that yesterday.  The amplifier's TF is flat at least up to 200 kHz. The Bode plots between the loop with and without the amplifier are pretty much the same. Thus, it is ok and won't cause a problem in the loop.

==setup==

The setup is similar to what I did in the previous entry, except the output of the marconi is connected with the amplifier. See blue arrow.

 2012_02_03_pll.png

 

==result==

PLL_TF.png

The TFs between the two cases have similar shape. So the amplifier will not be the limiting component. The magnitudes (in arbitrary unit) are slightly different because I did not attenuate the power by the same factor it was amplified.

 

The UPDH box will be modified next to see if we can increase the loop bandwidth.

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