The prediction of impedance using quasi-static field theory

It is demonstrated that the impedance of practical electromagnetic devices can be accurately predicted from first principles using quasi-static time-harmonic field theory. A general method for computing the impedance of electromagnetic devices is discussed. The method entails a two-step approach in which a field solution is obtained (assuming steady-state operation) and then used to compute a lumped-parameter equivalent circuit. The field solution is computed using finite element analysis. The method is demonstrated using a simple device consisting of a loop of copper wire fixed below an aluminum plate. Impedance values are computed for a frequency range of 100 kHz to 1 MHz and compared with measured data