Application of the phase coherence method for imaging with sparse multistatic line arrays

Sparse multistatic array concepts can offer cost-effective millimeter-wave and terahertz imaging solutions, while greatly reducing the system complexity. Despite the high design flexibility of sparse arrays the imaging quality could strongly be limited by unavoidable violations of the Nyquist-Shannon sampling criterion, which lead to significant grating lobes artifacts. Within this contribution we investigate the application of the phase coherence method to enhance the imaging quality. Simulations show a significant increase of the integrated side lobe ratio along the array's axis, which holds for undersampled effective apertures. Experimental results, which have been achieved with a factor 4 undersampled sparse line array operating in the W-band, demonstrate the potential of this approach not only in reducing grating lobes but also side lobes and clutter.