HFSS capacitor simulation
时间：03-26
整理：3721RD
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hi all,
has anyone been successful in simulating parallel plate (square) capacitors in HFSS?
I created two sheets with PEC boundary cond. to represent the plates, and between them created a rectangular sheet connecting the two plates. I gave it lumped port excitation. I tried making the lumped port connecting the centers of the plates, and also moved the lumped port away from the center of the plates towards the edges.
I also tried to model the plates as PEC rectangles to give some small thickness to the plates, instead of sheets.
Compared to the simple formula for parallel plate capacitor, I have not been able to extract the right capacitance, from C = 1/(2*pi*im(Z11)). I know that there could be fringing fields at work here, but I made the plate areas really big compared to the separation distance. My extracted capacitance is wildly off what is expected from the basic model.
Can somebody offer some advice?
has anyone been successful in simulating parallel plate (square) capacitors in HFSS?
I created two sheets with PEC boundary cond. to represent the plates, and between them created a rectangular sheet connecting the two plates. I gave it lumped port excitation. I tried making the lumped port connecting the centers of the plates, and also moved the lumped port away from the center of the plates towards the edges.
I also tried to model the plates as PEC rectangles to give some small thickness to the plates, instead of sheets.
Compared to the simple formula for parallel plate capacitor, I have not been able to extract the right capacitance, from C = 1/(2*pi*im(Z11)). I know that there could be fringing fields at work here, but I made the plate areas really big compared to the separation distance. My extracted capacitance is wildly off what is expected from the basic model.
Can somebody offer some advice?
Can you show more details about structure? Size?
an example would be a two 30mm x 30mm PEC sheets with 0.5mm gap spacing, simulating at 1 GHz. With capacitor plates modelled by 3d box, I'd do 30mm x 30mm x 0.5mm with PEC material. Radiation airbox is greater than wavelength/4 (0.3m) away in all directions from my structure. Lumped port is rectangle with dimensions 0.5mm x 0.5mm, connecting the two plates. Terminal line set from lumped port's end to end.
Perhaps this frequency is not good for the dimensions of my capacitor, but if so I do not know why. In general, is there a rule of thumb of for when HFSS doesn't give accurate results for a specific frequency relative to the size of my structure?