Ultra-Wide Band Near-Field Imaging System

An experimental ultra-wideband radar system prototype is presented for imaging objects located in the near field of the radar antennas. The system is primarily intended for through-matter, e.g. through-wall, target detection and imaging. The radar hardware is based on several novel technical solutions in the design of its electromagnetic (EM) and circuit components including a new antenna element with wide impedance and gain bandwidth. The same elements are employed for the transmit channel and the two-element receive array. The signal processing and target imaging algorithms are presented. Some results of indoor tests to image in 2-D the spatial position of a cylindrical object are reported. In particular, a brightest-spot recognition technique is demonstrated that uses a number of special radar calibration routines to set properly the time/range scale required for precise target localization and imaging while avoiding appearance of false target responses.