Calculation of the time domain z-component of the EM-near-field from the x- and y-components

This paper presents a time-frequency computation method for extracting the vertical component of magnetic near- field H_z(t) from the horizontal components H_x,y(t) by using the Plane Wave Spectrum (PWS) method. As PWS applies to frequency-domain quantities, a Fourier transform is used to convert between time and frequency-domain fields. The method is validated on the example derived from the time-domain EMC radiated emission modeling, in which a set of electric dipoles is excited by current pulses of ultra-short duration. A good agreement has been found between magnetic near-field H_z(t) extracted by the proposed method and that directly calculated from analytical formulae.