A simplified method for predicting common mode current on dipole and monopole structures

Many unintentional radiators can be represented as monopole antennas. Key to predicting their near field emissions is the calculation of common mode current on the antenna which is difficult at low frequencies. This paper demonstrates that quasi-static techniques are sufficient for computing the behavior of monopole and dipole structures up to at least the half wave resonance. Furthermore, lumped parameter RLC equivalent circuits are developed from quasi-static means and correlated to conventional antenna theory. The simplified approach provides insight into the important contributors to low frequency emissions.