3D imaging system based on a MIMO approach at 360GHz for security screening

An active MIMO system at 360 GHz as a part of the EU FP7 project TeraSCREEN is presented. A combination of geometric focusing in elevation and MIMO based digital beam forming in azimuth will provide real-time 3D images. The MIMO system consists of 16 transmitter and 16 receiver antennas within one single array. This configuration represents a linear array of 256 virtual antennas. This set-up allows an azimuth resolution of 0.078 degrees. To achieve an elevation resolution of 0.15 degrees, the combination of a fast moving plane reflector and a focusing elliptical mirror is used. An FMCW-Radar bandwidth of 30 GHz results in a range resolution of 5 mm. With this system high resolution 3D images can be generated with 4 frames per second. The principle of the system is presented including the functional structure and the hardware design. This is followed by the description of the 30 GHz module, providing the analogue input signal for the submillimeter wave multiplier chain to achieve a Terahertz signal at 360 GHz.