Menu

Discussion Forum

New Discussion
Filtra

Note: This discussion is about an older version of the COMSOL Multiphysics® software. The information provided may be out of date.

Discussion Closed This discussion was created more than 6 months ago and has been closed. To start a new discussion with a link back to this one, click here.

Electric field distribution of microelectrodes

Posted 23 mag 2012, 23:11 GMT-4 Low-Frequency Electromagnetics, RF & Microwave Engineering, Modeling Tools & Definitions, Parameters, Variables, & Functions Version 4.2a 1 Reply

Bashar Yafouz
Send Private Message Flag post as spam

Please login with a confirmed email address before reporting spam

Hi everyone,

I am a new user to Comsol. I want to see the electric field distribution of a set of microelectrodes. The frequency of my AC excitation signal is in MHz.

1- I have chosen RF module to do this task. Is that the correct choice?

2- How can I input an "AC" signal? I mean, when I write "20*sin(10^6*t) " as the Vo in the terminal electric potential, it gives me an error coz "t" is undefined variable.

Thanks in advance for your help.
1 Reply Last Post 24 mag 2012, 01:09 GMT-4
Ivar KJELBERG COMSOL Multiphysics(r) fan, retired, former "Senior Expert" at CSEM SA (CH)
Send Private Message Flag post as spam

Please login with a confirmed email address before reporting spam

Posted: 1 decade ago 24 mag 2012, 01:09 GMT-4
Hi

check the doc, the decision between ACDC and RF comes from the relative size of your model compared to the EM wavelength size (which depends on the material index or epsilon_r. If the wavelength is very long compared to the model extent size it's rather ACDD, if the wavelength is much shorter than the model size its RF, when in the middle none or both it depends and you are in the grey zone ;( a good way is to compare both results and try to understand the simulitudes or differences then observed.

For the "AC" signal you have 2 approaches, time series with explicit V0*sin(2*pi*f*t) or harmonic development (frequency sweep) in omega=2*pi*freq mode, then you define amplitude and phase and the frequency or its sweep range. The latter is by far the cheapest, computationally

--
Good luck
Ivar
Hi check the doc, the decision between ACDC and RF comes from the relative size of your model compared to the EM wavelength size (which depends on the material index or epsilon_r. If the wavelength is very long compared to the model extent size it's rather ACDD, if the wavelength is much shorter than the model size its RF, when in the middle none or both it depends and you are in the grey zone ;( a good way is to compare both results and try to understand the simulitudes or differences then observed. For the "AC" signal you have 2 approaches, time series with explicit V0*sin(2*pi*f*t) or harmonic development (frequency sweep) in omega=2*pi*freq mode, then you define amplitude and phase and the frequency or its sweep range. The latter is by far the cheapest, computationally -- Good luck Ivar

Note that while COMSOL employees may participate in the discussion forum, COMSOL® software users who are on-subscription should submit their questions via the Support Center for a more comprehensive response from the Technical Support team.

Suggested Content