Home Forums FDTD Observation Area Analysis, Field Distributions, dB

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• #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 SimĂµes Rosa

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• #25854

Good evening,

Could someone help me?

Regards,

Miguel SimĂµes Rosa

• #26690
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
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
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.

• #27025

Thanks very much Damien! It was a good help! Best regards

• #26914
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
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.

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• #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