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Observation Area Analysis, Field Distributions, dB

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(joined February 2015)
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Good evening,

Could someone explain to me what is the advantage of using decibels in the Observation Area Analysis, in DFT, for calculating the field distributions?

It would be a very good help if someone could explain this to me.

Best regards,

Miguel Simões Rosa

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Responses (12):

    • #25482

      Good evening,

      Could someone explain to me what is the advantage of using decibels in the Observation Area Analysis, in DFT, for calculating the field distributions?

      It would be a very good help if someone could explain this to me.

      Best regards,

      Miguel Simões Rosa

      Attachments:
    • #25854

      Good evening,

      Could someone help me?

      Regards,

      Miguel Simões Rosa

      Instituto Superior Técnico

    • #26690
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      Md.Adnan Riaz
      Participant

      Hi Miguel. I am sorry that I can’t help you about this.Can you please tell me what will be the units of DFT Ey for the image view and plane view that I have attached here?

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    • #26792

      Hello! It’s V/m. How did you put that scale bar?

    • #26802
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      Md.Adnan Riaz
      Participant

      Thank you Miguel. Is it V/m also for DFT Ey(first graph)? I didn’t add the scale, it came with OptiFDTD itself. Miguel I have some other questions about power calculation, can you help me?

    • #26846

      Yes ask, no problem,. If I could I will try to answer.

    • #26901
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      Damian Marek
      Participant

      Decibels allow you to see a larger range of values than a normal scale. I generally stick with the linear scale for observation areas, but say you want to see some feature which is much smaller than the main part of the graph. It will show up clearer with a dB scale.

      +1
    • #26914
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      Md.Adnan Riaz
      Participant

      Is there any way to calculate the input and output power to find the power loss during propagation? I have tried to find it using observation point but I could not understand what the Y axis indicates. Is it power (dB) VS wavelength?

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      • #27027

        Sorry for the late Adnan! I usually work with the observation areas. I think that in the Y is the power normalized and in the decibel scale, I have that idea because of the options that you have selected. Why you don’t use a observation area?

    • #27032
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      Md.Adnan Riaz
      Participant

      Its fine Miguel no problem! Ok I have just simulate one of the design using observation area. Can you tell me by selecting which option I can find the propagation loss or transmission loss? Please check the attachment.

    • #27153

      Hello! If you the field distribution select the wavelength that you desire and select update graph. For the power, go to Power Spectrum, I think that is this that you want. Write the minimum and maximum wavelengths, select the normalize with and finally calculate. Don’t choose too much sample points, it takes time.

    • #27287
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      Md.Adnan Riaz
      Participant

      Hi Miguel! Thank you so much for your reply. I have tried according to your suggestion and it worked. Miguel you explain me the graph that I have attached here? Here the observation point1 and point2 refer to starting and ending point of the waveguide (input and output) respectively.I got higher value for ouput compared to input, is this possible? If so, what is the explanation according to your point of view? Thanks in advance.

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