Illumination of humans in active millimeter-wave multistatic imaging

The increasing demand on developing advanced imaging methods for the personnel screening applications has motivated many researchers to explore new techniques suitable to the emerging problem. Among the known methods, the active imaging using multistatic arrays in connection to digital-beamforming proofs efficient imaging with high image quality in terms of dynamic range and resolution. As any active imaging method, the illumination of the imaged object becomes an issue due to specular reflections. The human skin causes relatively strong specular reflections in the millimeter-wave range, and hence hinders the visibility of the body to some extend. Therefore, a consolidated understanding of the geometrical problem is essential for the optimization of the illumination issue. In this work, a simulation model is presented to address the problem precisely; and a measurement verification in the frequency range of 75 to 82 GHz is made to demonstrate the exactness of the proposed model. Additionally, an illumination analysis of a typical screening scenario of a human is presented.