Hi...I have a setup as shown in the figure above (Setup.jpg). In this, I have two parallel plates of PEC material (the top plate is 1V, the bottom plate is grounded, i.e., 0V), and in between them is a dielectric slab (er=5.515,tand=0.0003) over which I have 30 cylindrical segments of Aluminum material having a constant separation between them. The last segment is connected to the ground plate (0V). The excitation is a double exponential signal of peak amplitude 1MV, Trise =0.4us, and Trise=70us (a standard waveform). I have the Et=0 boundary condition imposed on the top and ground plates and all others as Ht=0 to eliminate any fringe fields and have a uniform E-field directed from the top plate to the ground plate (verified the boundary conditions).
Now, when I simulate the setup using LF TDS (Low-Frequency Time domain solver), the output E-field with the top view is shown in the figure E-fieldDistribution.jpg. The E-field is directed from the top plate towards the ground plate in -ve Z-direction.
My query is:
Why is the E-field strongest near the bottom segment, which is grounded, than the top segment, which is nearer to the top positive plate with excitation of 1MV peak?
