Computational and Experimental Analysis of Spatial Distribution and Spectral Composition of Electromagnetic Fields Inside a Vehicle Cabin

Abstract

This paper estimates the total electromagnetic load in the passenger compartment. A computational model is proposed based on the numerical solution of Maxwell’s equations and the specular reflection method for near-field emitters, accounting for the shielding properties of the metal body and attenuation through the glazing apertures. Theoretical calculations and field measurements were performed using a spectrum analyzer (Narda NBM-550) and isotropic probes over the frequency range from 10 Hz to 3 GHz during various operating modes of the power plant and auxiliary electrical equipment. The comprehensive measurement campaign utilized two complementary metrological systems to cover the entire spectrum: a dedicated Narda EHP-50F isotropic analyzer was deployed for the low-frequency domain (10 Hz–100 kHz), while high-frequency electromagnetic and radiofrequency components (100 kHz–3 GHz) were acquired using a Narda NBM-550 broadband field meter equipped with isotropic electric (EF-0391) and magnetic (HF-3061) probes. The maximum low-frequency magnetic induction (B max = 2.4 μT) was recorded near the driver’s pedal unit and the engine shield, attributable to generator field leakage and ignition-system transients. In the high-frequency range (2.4 GHz), resonant effects of the metal body caused standing-wave interference nodes, producing electric field strength peaks of 8.5–9.5 V/m. Although the recorded field parameters are within the limits specified by ICNIRP and national sanitary standards, they pose a chronic exposure risk to drivers traveling long distances. Design recommendations are proposed to optimize the wiring topology and local shielding.