Time-Domain Distortion Analysis of Wideband Electromagnetic-Field Sensors Using Hermite–Gauss Orthogonal Functions

A time-domain distortion characterization of electromagnetic-field sensors is performed using Hermite-Gauss functions. For every electromagnetic-field sensor, a transformation matrix is calculated in the spanned Hermite-Gauss signal subspace. The calculated matrix is then compared to a reference transformation matrix to give a measure of distortion. Distortion characteristics for different frequency ranges are calculated to obtain a spectral interpretation. Unique properties of Hermite-Gauss functions under the Fourier transform are used to calculate the distortion characteristics from a single set of time-domain measurements. Distortion characteristics of an asymptotic conical dipole are compared to three wire monopoles of different lengths. A time-domain simulation based on solving an electric-field integral equation using the method of moments is performed. Distortion characteristics resulted from the simulation and those obtained using measurement data are compared to each other. Finally, the sensitivity of the sensors is taken into account in the distortion analysis.