Transient UWB Antenna Near-Field and Far-Field Assessment From Time Domain Planar Near-Field Characterization: Simulation and Measurement Investigations

In this paper, we present the experimental validation of time domain (TD) near-field to near-field (NFNF) and near-field to far-field (NFFF) transformations for ultrawideband (UWB) antenna transient characterization. The used computation schemes for near-field to near- or far-field transformations are based on the Green's function representation of the radiated field where NF and FF are directly calculated in the TD. The first step of the validation process comprises the electromagnetic simulation results dedicated to evaluate the accuracy of NFFF and NFNF transformations. The second step uses near-field measurement data of a Vivaldi antenna to validate the developed computation schemes, whereas the measurement and calibration procedures are fully described. The measured NF data using Supelec planar and cylindrical near-field facilities are also compared with the electromagnetic simulation transient results of the Vivaldi antenna.