Phase-Based Range-Enhanced Millimeter-Wave Imaging Technique for Multistatic Planar Array

A millimeter-wave (mmW) range enhancement imaging technique for multistatic planar arrays is presented. The echo in an active mmW imaging system that contains both amplitude and phase information, and the latter can be potentially exploited for improving imaging performance in the range direction. With the help of a two-dimensional (2-D) phase unwrapping scheme, and the multi-input–multi-output range migration algorithm (MIMO-RMA) for a multistatic planar array, along with the requisite pretreatment processes such as target extraction and phase error correction for the reconstructed image region, a reconstructed image having a finer range profile could be achieved. The underlying principle of the phase information exploitation to achieve finer range distance information is discussed, the range enhancement imaging implementation steps are outlined, and the necessary pretreatment processes in simulation and experiment are introduced. The efficiency of the proposed approach is analyzed theoretically and demonstrated experimentally. Numerical simulation and experimental results show that the reconstructed image using the new range enhancement imaging technique contains the promised finer range distance information.