Spatial-domain technique to overcome grating lobes in sparse monostatic mm-wave imaging systems

In this work, a spatial-domain technique is introduced to mitigate grating lobes in sparse monostatic arrays targeting applications such as low-cost real-time mm-wave imaging systems. Standard algorithms, such as synthetic aperture radar (SAR) techniques, are susceptible to grating lobes and result in images with significantly degraded quality. In order to suppress artifacts due to the grating lobes, a new spatial aggregation technique is introduced, which replaces point-scatterer based basis function by a new set of spatially extended basis functions. The efficacy of the proposed method is demonstrated using experimental data. Our hardware testbed is a 60 GHz continuous-wave radar transceiver, equipped with a movable mechanical platform to emulate a 2-dimensional array of sensors.