Analytical Prediction of EMC Properties of an Automotive Horn

THE DC TO HIGH FREQUENCY impedance of an automobile horn is calculated from detailed drawings for frequencies from zero to 200 MHZ. The calculations are made using the finite element method which accounts for magnetic skin and proximity effects due to eddy currents. Measurements with a high frequency network analyzer confirm the calculated complex impedance at various frequencies. This calculation method will enable the design engineer to know the EMC (Electromagnetic Compatibility) properties of any passive noise generator before prototype construction of components.