Performance of wavefront migration imaging in the near field of the antennas

The performance of an ultra wideband (UWB) imaging system has been studied for targets placed in the near field of the antennas. The targets in the proximity of antennas are causing additional coupling between the antennas and thus the distortion of transmitted pulses. As the most algorithms for UWB imaging utilize the information about the shape and delay of the received pulses the distortions may influence the quality of the image. The degree of pulse distortion depends on the size of the target, its material properties and distance to the antennas. It is shown that it is possible to obtain the image of the target already at small distances even if some signal distortion due to the coupling occurs.