Multistatic Short Range Ka-Band Imaging System

This paper presents the concept of a Ka-Band (26.5 - 40 GHz) multistatic active short range imaging system. The motivation for this work was the development of a fast scanning imaging system for non destructive testing (NDT) or security scenarios. The goal was to derive a 3D reconstruction of the device under test (DUT). The imaging system consists of a linear receive array and spatially distributed transmitters with non focussing antenna elements. This transmit/receive array is moved perpendicular to the array dimension. By switching between each transmitter and simultaneous reception of the scattered field by each receiver, a fast sampling of the 2D aperture plane is achieved. Due to unfocussed antenna elements numerical reconstruction algorithms have to be applied for a highT lateral resolution. An aperture synthesis concept is presented to reconstruct the raw data. It is based on the separation of the reconstruction kernel into a horizontal and a vertical part. Range resolution is achieved by a broadband stepped frequency continuous wave (SFCW) radar. In order demonstrate the efficiency of the new reconstruction kernel first results are demonstrated with simulated and measured data.