# Electrical modeling of multilayer structure

If I have a construction of layers wherein the topmost layer is conductive, followed by two different insulation materials in between, and a bottom structural layer that is a partially conductive composite, how can I model this electrically?

Considering these are huge area layers (10m2 each), would this constitute the electrical equivalent of a stackup?

Additionally, if I ground the structural material to Earth ground, do I have to worry about charge buildup at the two conductive plates?

EDIT: Adding complexity, if there's a conductive material (CM2) beneath this stackup some distance, d, away, how can I assess the impact on the CM2 in the presence of charge buildup when the structural material is left ungrounded?

how can I model this electrically?

It really depends on what you need to model and to what accuracy. If you are measuring something below 100Mhz the somethin like the model you have would be accepable. A DC model would look like the one you have. If you need to model something in the GHz, you'll also have to model the dielectric and you may have capacitance of layers/ transmittance/reflectance and absorbtion that you need to worry about, a simple circuit model might also be inadequate.

Additionally, if I ground the structural material to Earth ground, do I have to worry about charge buildup at the two conductive plates?

Whenever you have two conductive surfaces, they form a capaictor. If the structural material is grounded, then one end would be grounded which may be good or bad for your application vs a floating conductive plate that could be any potential. If you apply a voltage to the top conductor the bottom conductor will respond and change it's voltage via capacitor models.

• What would be bad about it? Also what would the model look like for GHz Jan 18 at 4:52
• Depends on the materials Jan 18 at 6:10
• CM1 and CM2 are copper, Ins 1 is polyurethane, Ins 2 is teflon. Structure is graphite-epoxy composite Jan 18 at 21:17
• The model will look simmilar, but you'll have to substitute an parallel resistance and also care about how E_r is affecting capacitance. You may also need to substitute in series inductance and resistance for any wires attached to the device. pF's will make a difference. Jan 18 at 21:47
• Sorry I don't follow, any chance you could show the corrected model? A visual would be very helpful Jan 18 at 22:21