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Entry  Thu Jul 26 10:58:02 2012, Sarah, DailyProgress, ISS, ISS Box Transfer Function 8x
    Reply  Mon Jul 30 20:26:39 2012, Sarah, DailyProgress, ISS, ISS Box Transfer Function 13x
       Reply  Mon Aug 6 18:28:08 2012, Sarah, DailyProgress, ISS, ISS Box Transfer Function 7x
          Reply  Tue Aug 7 03:00:31 2012, rana, DailyProgress, ISS, ISS Box Transfer Function 
          Reply  Wed Aug 8 20:57:15 2012, Sarah, DailyProgress, ISS, ISS Box Transfer Function 
          Reply  Wed Aug 8 23:03:52 2012, Sarah, DailyProgress, ISS, ISS Box Transfer Function 7x
Message ID: 1037     Entry time: Wed Aug 8 23:03:52 2012     In reply to: 1033
Author: Sarah 
Type: DailyProgress 
Category: ISS 
Subject: ISS Box Transfer Function 

Today there were further modifications made to the ISS box in an attempt to get more suppression.

Modifications:

I attached the updated schematic, but several resistor values were changed in the filter stages. Additionally, we found that there were additional components between the PD input and the second page of the schematic causing problems, which are not pictured on the schematic. The link to the schematic for what goes on right after the PD input is here: PD input schematic. These additional components include an amplifier which was saturating our DC signal before it could get to the high pass filter. We removed the amplifier.

Transfer function and RIN:

The transfer function of the box plotted with that calculated in LISO is:

TF.png

 

Unfortunately, problems arose in implementing the ISS with the above transfer function. The following plot shows the resulting RIN suppression, or lack there of:

RIN_wack.png 

Using the flip sign stage in the ISS box, the transfer function becomes:

TF_wack.png

Where there is clearly positive feedback in the phase. However with this orientation, there is a clear suppression of the RIN:

RIN.png

The corresponding frequency noise suppression is:

nb.png

Cl

Attachment 2: TF.fig  307 kB
Attachment 3: D080351.pdf  1.486 MB  | Hide | Hide all
D080351.pdf D080351.pdf D080351.pdf
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