| DC motors are known sources of radio frequency electromagnetic noise produced by arcing at the motor brushes. A simplified model of electromagnetic radiation from a DC motor and associated wiring harness is desired to guide engineers in the design process. Of particular interest is their behavior at low frequencies in a reverberation chamber. Different methods are used to devise a voltage transfer function between a device under test (DUT) and a monopole antenna for near field low frequency testing in a reverberation chamber. A simple scaling factor is used to transform low frequency monopole antenna data between different reverberation chamber configurations. Further refinement in the modeling is based on common mode current. Test data indicated that a simple equivalent RLC circuit could represent the common mode current. The validity of the approach is shown using the Electric Field Integral Equation. Various quasi-static and static models were used to compute the circuit parameters. Furthermore, a second circuit was shown to relate the common mode current to the receiving antenna voltage. Moment method models and test data demonstrate this relationship. |
