Discrepancy in Transmission coefficients using DFT monitor and s params group

- November 20, 2024 at 9:44 am
  
  ph23resch01002
  Subscriber
  
  Dear Sir/Madam,
  
  I have used the s params analysis group, to calculate the s and s polarization and transmission coefficients. When I use the transmission monitor, I get a plot as shown below
  
  Then, I have used the result S from the s_params analysis group to calculate the T for the x polarised incidence. I have done the abs(s12)^2, I got the following plot,
  
  As far as I know, if we have to measure the transmission coefficients, we must do the abs(S_12)^2. But why do I get such a discrepancy? Can you shed some light on it?
  
  Thank you.
- November 20, 2024 at 6:01 pm
  
  Amrita Pati
  Ansys Employee
  
  Hi,
  Yes, I believe the results should be the same. Is the resolution of data/number of points used to plot the graph in both cases same?
  Regards,
  Amrita
- September 30, 2025 at 4:00 pm
  
  jonathan.atkinson
  Subscriber
  
  Is there a solution to this discrepancy? I am having the same issues in a simulation. The data points are the same.