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.
Adding Sheet Resistance
Posted 04.11.2025, 09:45 GMT-5 1 Reply
Please login with a confirmed email address before reporting spam
Hi, I want to add sheet resistance to my simulation. The thickness of substrate 1mm and above which there is printed ink structure having a sheet resistance value say R_s. I want to obtain the microwave reflection characteristics of the FSS. There is no option to add sheet resistance. (In impedance boundary condition or in transition boundary condition there is only option to add conductivity (S/m)) not sheet conductivity(S).) The thickness of the ink layer is unknown to me and it is very small compared to the thickness of substrate. Is there any way to add sheet resistance. (may be through some boundary condition or structure or any other way)
Please login with a confirmed email address before reporting spam
I may not be understanding your problem completely, but it seems to me that you can represent the behavior of the resistive layer by assigning it a conductivity (S/m). You can relate DC resistance to the conductivity by the usual formula, 
where 
is the length (distance along the current path), 
is the cross-sectional area to the current flow, and 
is the conductivity. Then for the RF behavior, set an impedance boundary condition and tell it to use the properties from the associated material, the latter which then does not have to meshed volumetrically. This approach should be acceptable if your layer thickness is much greater than a skin depth. If not, then either mesh the volume of the layer itself, which may be computationally intensive (and don't use the impedance boundary condition) or replace the layer by an external resistor equivalent circuit (via the .ec physics in the AC/DC module, if you have that), if that is consistent with how your resistive layer is actually behaving.
Scientific Applications & Research Associates (SARA) Inc.
www.comsol.com/partners-consultants/certified-consultants/sara
