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RF frequency domain scattering electric field module- normalization of scattered field Ex by the background field Ebx

Posted Mar 27, 2012, 5:32 p.m. EDT RF & Microwave Engineering, Studies & Solvers Version 4.2a 7 Replies

Brandon Demory
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I am uncertain if I am incorrect in my assumption, so I have come here hoping someone can clarify for me.

emw.Ex -displays the scattered electric field
emw.Ebx -is initial background electric field used for solving the problem
I want to normalize (emw.Ex/emw.Ebx) to see the enhancement. I am plotting on a cross section where emw.Ebx is almost a constant value at this height (~0.26 V/m).

When I plot (emw.Ex/emw.Ebx) vs when I plot (emw.Ex/0.26) where 0.26 is the value of emw.Ebx at this cross section, I get two different plots.

Is (emw.Ex/emw.Ebx) the proper way to plot this enhancement?

Maybe I am interpreting emw.Ex or emw.Ebx incorrectly.

Thank you,

Brandon

7 Replies Last Post Jul 21, 2013, 9:42 p.m. EDT
Alexander Kuznetsov
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Posted: 1 decade ago Mar 27, 2012, 5:36 p.m. EDT
emw.Ex is the total field. Scattered field is (emw.Ex-emw.Ebx)
emw.Ex is the total field. Scattered field is (emw.Ex-emw.Ebx)
Brandon Demory
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Posted: 1 decade ago Mar 27, 2012, 5:42 p.m. EDT
So to normalize to see enhancement, I would need:
(emw.Ex-emw.Ebx)/(emw.Ebx)

Based on your response is this the correct formulation
So to normalize to see enhancement, I would need: (emw.Ex-emw.Ebx)/(emw.Ebx) Based on your response is this the correct formulation
Alexander Kuznetsov
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Posted: 1 decade ago Mar 27, 2012, 6:06 p.m. EDT
It depends what you mean by "enhancement" :)
In my case, I use the following quantity integral(abs(Escattered)^2)/integral(abs(Ebackground)^2).
It depends what you mean by "enhancement" :) In my case, I use the following quantity integral(abs(Escattered)^2)/integral(abs(Ebackground)^2).
Brandon Demory
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Posted: 1 decade ago Mar 27, 2012, 6:26 p.m. EDT
Well I can clarify. I am dealing with an electric field being incident into a metal nanoantenna cavity from a substrate. So there is amplification of the electric field due to local surface plasmons, which increases the amplitude of my electric field in the cavity. I am trying to normalized the scattered field by the background incident field to get a sense of this quantity.

This is something like (|Ecav|/|Esig|)^2 which I believe is an enhancement factor.

So I was assuming Ecav/Esig was something like emw.Ex/emw.Ebx.

I am to give your expression a try.
In your expression is Escattered= (emw.Ex-emw.Ebx)
and Ebackground = emw.Ebx

I am not sure how to do the integration on my 2-D surface plot but that is a separate issue.
Well I can clarify. I am dealing with an electric field being incident into a metal nanoantenna cavity from a substrate. So there is amplification of the electric field due to local surface plasmons, which increases the amplitude of my electric field in the cavity. I am trying to normalized the scattered field by the background incident field to get a sense of this quantity. This is something like (|Ecav|/|Esig|)^2 which I believe is an enhancement factor. So I was assuming Ecav/Esig was something like emw.Ex/emw.Ebx. I am to give your expression a try. In your expression is Escattered= (emw.Ex-emw.Ebx) and Ebackground = emw.Ebx I am not sure how to do the integration on my 2-D surface plot but that is a separate issue.
Alexander Kuznetsov
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Posted: 1 decade ago Mar 27, 2012, 8:46 p.m. EDT

I am not sure how to do the integration on my 2-D surface plot but that is a separate issue.


That's an easy part. Define integration operator on your domain (Definition-Model Couplings-Integration). Then in post-processing use intop1(abs(field)) to get the value of integral.

This way you can define amplification inside the entire cavity. I don't think the amplification at particular points of the cavity has much meaning.
[QUOTE] I am not sure how to do the integration on my 2-D surface plot but that is a separate issue. [/QUOTE] That's an easy part. Define integration operator on your domain (Definition-Model Couplings-Integration). Then in post-processing use intop1(abs(field)) to get the value of integral. This way you can define amplification inside the entire cavity. I don't think the amplification at particular points of the cavity has much meaning.
Naren Viswanathan
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Posted: 1 decade ago May 16, 2013, 1:50 p.m. EDT
Could someone clarify how to specify the face where the background electric field is incident on the system?
I have an air block with spherical scatterers embedded in it. The background E field needs to be incident on one of the faces of the cube, and I need to study the fields within the block. I am using scattering boundary condition for all the faces of the block.
Could someone clarify how to specify the face where the background electric field is incident on the system? I have an air block with spherical scatterers embedded in it. The background E field needs to be incident on one of the faces of the cube, and I need to study the fields within the block. I am using scattering boundary condition for all the faces of the block.
Tianjing
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Posted: 1 decade ago Jul 21, 2013, 9:42 p.m. EDT
The same question.

Thanks in advance.
The same question. Thanks in advance.

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