Radar imaging based on multiple non-coherent antennas

A concept for radar imaging based on multiple incoherent millimeter wave antennas is presented. The goal is to realize 3D-Imaging, where the object moves along a line and passes a linear array of antennas. In radar imaging, the resolution limit depends on the used wavelength and the maximum aperture, that can be achieved. However, the creation of a large aperture incorporates the use of many radar antennas in the line array approach, which increases the hardware costs drastically. To reduce the hardware complexity, a novel radar principle is introduced, which does not require a coherent coupling between transmitter (Tx) and receiver (Rx), but a reference reflector. The Rx performs just a RP-power measurement for each frequency step in a stepped frequency continous wave (SFCW) setup. After preprocessing the raw data, any focusing algorithm can be used to obtain the 2D image. Multiple 2D images can be combined to 3D with backprojection. The principle of operation is validated experimentally using a SFCW radar setup operating from 73 to 83 GHz and an observation scene with two metallic spheres and a metal plate acting as a reference object.