Compact UWB Probe for Near-Field Microwave Target Detection and Imaging

The numerical analysis and experimental characterization of an ultra-wideband (UWB) probe designed for near-field target detection and imaging are reported. The configuration, based on transverse electromagnetic (TEM) horn, has two curved launching planes terminated with resistively loaded feedback loop and a U-shaped plane serving as the reflector. Resistive loads have been added to improve the performance at low frequencies in the UWB band. Numerical simulations and experimental measurements have been analyzed to assist with the characterization of the probe. It is demonstrated that the antenna exhibits a low return loss over a wide frequency range from 1 to 12 GHz. The spatial distribution of radiated energy is characterized in the frequency domain, using single-frequency radiation patterns in numerical simulations. A study of the target detection capability of the UWB probe is also included. The probe can be especially applied as the element in UWB radar-based detection and imaging systems.