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Message ID: 2389     Entry time: Mon Aug 12 14:23:24 2019
Author: ScottA 
Type: DailyProgress 
Category: RFAM 
Subject: Decrease in TF due to Bias Tee 

To determine if the loss in gain seen by the new eom driver (SN:06) was due to the driver itself or just because of the addition of the bias tee, I took the transfer function of the old eom driver with and without the bias tee. This plot shows the LTspice simulated transfer function with and without the bias tee, as well as the effect of adding the bias tee to either driver. Here are some take-aways:

  • In both cases, there is a similar reduction in the peak height and increase width of the peaks.
  • This indicates the SN06 board is not the issue and it is in fact the bias tee causing this change in gain.

It seems we cannot introduce a bias tee without facing a reduction in the gain of the driver.

Attachment 1: Transfer_EOM_drivers_Meas_vs_LTspice.pdf  33 kB  Uploaded Mon Aug 12 17:59:11 2019  | Hide | Hide all
Transfer_EOM_drivers_Meas_vs_LTspice.pdf
Attachment 2: Real_EOM_TF_ltspice_comparison.zip  2.959 MB  Uploaded Mon Aug 12 18:05:38 2019
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