Capacitance and Conductance Solution

The capacitance (C) and conductance (G) matrices for a system of conductors and dielectric objects are calculated together in the field solver.

Q3D takes the following steps:

• Divides the surfaces of conductors and dielectric objects into a triangular mesh (It is not necessary to mesh the interior of objects for this solution).
• Applies a 1 Volt excitation to one of the signal nets, and 0 volts to the others.
• Uses the fast multipole solver to compute the distribution of charges on the conductor surfaces, and bound charges on the dielectric surfaces. These charges are constrained by certain boundary conditions described below.
• Sums up the free charges on the conductor surfaces to evaluate one column of the capacitance and conductance matrices. These charges are in general complex quantities. The real part determines the capacitance and imaginary part determines the conductance.
• The above process is repeated, with each signal net being set to 1 Volt in turn while the other nets are maintained at 0 volts, until solutions have been obtained for each net.