UWB Sensor Characterization for Radar Sensing and Imaging in Superluminal Propagation Regions

This article investigates the pulse propagation in the near field of a transmitter and reflector from the perspective of radar sensing and imaging. The peaks of the radiated and reflected pulses were found to have traveled at superluminal speeds in the near field of radar. The conceptual explanation and experimental demonstration of the unique properties of the radiated and reflected pulses and their impact on near field radar imaging are presented in this article. To confirm the superluminal propagation, in this study, we considered several ultrawideband (UWB) sensors and scatterers. The physics behind the superluminal propagation and pulse shape change in the radar near field is demonstrated using the Huygens principle, and a method to improve the imaging of radar in the near field while using synthetic aperture techniques is also proposed.