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RF module or Wave Optics ??

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Hi,

I am trying to simulate the wavelength/ frequency transmission and reflection of a nanoscale cross-dipole antenna on a dielectric substrate.

For this I have taken the approach of the RF module (emw) "Freq Selective Surface with a Split Ring resonator" example as a starting point. Resonance as at 4.6 GHz but I have scaled the frequency up and the geometry down for resonance at around a wavelength 6-10 um. Two ports and S parameters are used to calculate reflection and transmission. Simulations run, but I do not feel very certain about the results

A more suitable approach maybe to use the Wave Optics module (ewfd) ???
Any idea's or comments on this ?

I am not very familiar with COMSOL in RF design and I am using 4.4 at the moment.

Thanks,
Ger

3 Replies Last Post Feb 24, 2016, 10:05 p.m. EST
Jeff Hiller COMSOL Employee

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Posted: 10 years ago Mar 3, 2015, 10:48 a.m. EST
This link might help:
www.comsol.com/blogs/computational-electromagnetics-modeling-which-module-to-use/
Best,
Jeff
This link might help: http://www.comsol.com/blogs/computational-electromagnetics-modeling-which-module-to-use/ Best, Jeff

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Posted: 10 years ago Mar 31, 2015, 10:25 a.m. EDT
Thank you for the tip.
It seems that the RF module is most suitable for structures in the same order of magnitude as the wavelength.
Still the results I have , ar not as expected. The COMSOL examples are not really covering my structure (see fig)
I just need to tune the crossdipoles for optimal taransmission at 75 THz.
Probably my definitions of the E-field ( or should I use the H-field ??) are not correct
I have used emw and a wave excitation port : E= 0 (x,z) Ey = exp(-i*k_x*x)*exp(-i*k_y*y) [V/m]
Below the crossdipole is a port without power : E= 0 (x,z) Ey = exp(-i*k_x*x)*exp(-i*k_y*y) [V/m]
and i am plotting Reflection and Transmission emw.S11 and emw.S12.
Wavelength is in the mid-infrared ( 75 THz). Anyone experience with these type of simulations

I'm quite stuck so any help is very welcome

Best regards,
Thank you for the tip. It seems that the RF module is most suitable for structures in the same order of magnitude as the wavelength. Still the results I have , ar not as expected. The COMSOL examples are not really covering my structure (see fig) I just need to tune the crossdipoles for optimal taransmission at 75 THz. Probably my definitions of the E-field ( or should I use the H-field ??) are not correct I have used emw and a wave excitation port : E= 0 (x,z) Ey = exp(-i*k_x*x)*exp(-i*k_y*y) [V/m] Below the crossdipole is a port without power : E= 0 (x,z) Ey = exp(-i*k_x*x)*exp(-i*k_y*y) [V/m] and i am plotting Reflection and Transmission emw.S11 and emw.S12. Wavelength is in the mid-infrared ( 75 THz). Anyone experience with these type of simulations I'm quite stuck so any help is very welcome Best regards,


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Posted: 9 years ago Feb 24, 2016, 10:05 p.m. EST
Hey,
I wanted to ask you something. I want to simulate a nanoantenna, a gold dimer. Now I want to calculate the Near-Field enhancement of the nanoantenna. I can calculate the scattering cross-section (help from the built in model). But I still can't figure out how to calculate the near field enhancement of the antenna

How can I do this in comsol? Thanks.
Hey, I wanted to ask you something. I want to simulate a nanoantenna, a gold dimer. Now I want to calculate the Near-Field enhancement of the nanoantenna. I can calculate the scattering cross-section (help from the built in model). But I still can't figure out how to calculate the near field enhancement of the antenna How can I do this in comsol? Thanks.

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