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.
Open boundary condition for time-dependent EM simulations
Posted Jan 26, 2015, 8:12 p.m. EST RF & Microwave Engineering, Studies & Solvers Version 5.0 3 Replies
Please login with a confirmed email address before reporting spam
Well, as the title indicates, I would like to know how to model in COMSOL an open boundary condition for EM simulations, using the transient solver.
An open boundary condition is the one which absorbs all EM radiation, with very little reflections going back to the analysis domain. What I am looking for is a boundary condition that performs the same as the PML, but in time domain simulations.
I am asking this because I am working on GPR (Ground Penetrating Radar). For that application I need to model the soil as infinite (so radiation that gets into the soil is not reflected back, as it happens in practice), and this could be accomplished by adding an open boundary condition underneath the soil.
Any help is highly appreciated.
Best Regards,
Ramon Araujo
An open boundary condition is the one which absorbs all EM radiation, with very little reflections going back to the analysis domain. What I am looking for is a boundary condition that performs the same as the PML, but in time domain simulations.
I am asking this because I am working on GPR (Ground Penetrating Radar). For that application I need to model the soil as infinite (so radiation that gets into the soil is not reflected back, as it happens in practice), and this could be accomplished by adding an open boundary condition underneath the soil.
Any help is highly appreciated.
Best Regards,
Ramon Araujo
3 Replies Last Post Jan 27, 2015, 8:30 a.m. EST
Please login with a confirmed email address before reporting spam
Posted:
9 years ago
Ramon,
Use Scattering Boundary Condition to minimize back reflection in time domain analysis.
Regards,
Sergei
Use Scattering Boundary Condition to minimize back reflection in time domain analysis.
Regards,
Sergei
Please login with a confirmed email address before reporting spam
Posted:
9 years ago
Hello Sergei, thanks for the quick reply.
So the scattering BC is sufficient for my purpose or does it make sense to place a PEC boundary after the scattering BC? People do that for the FDTD method, for example.
Thank you.
So the scattering BC is sufficient for my purpose or does it make sense to place a PEC boundary after the scattering BC? People do that for the FDTD method, for example.
Thank you.
Please login with a confirmed email address before reporting spam
Posted:
9 years ago
Ramon,
No, you don't need PEC after SBC.
Make sure you use appropriate Scattered wave type - I guess it would be Spherical wave in your case.
Regards,
Sergei
No, you don't need PEC after SBC.
Make sure you use appropriate Scattered wave type - I guess it would be Spherical wave in your case.
Regards,
Sergei