A Comparison of Image Reconstruction Versus Array Layout in a 24-Element 38-GHz Active Incoherent Millimeter-Wave Imaging System

Abstract

We compare the image reconstruction quality of two array layouts in a 24-element 38-GHz active incoherent millimeter-wave (AIM) imaging system. Compared to traditional passive millimeter-wave imaging systems, AIM imaging uses the transmission of spatiotemporally incoherent signals, leading to better sensitivity and enabling image reconstruction at rates exceeding 650 fps. Fast imaging of conducting objects may lead to improvements in a number of applications including non-destructive evaluation. AIM image reconstruction quality, and thus the capability to diagnose defects, is highly dependent on the physical layout of the antennas. In this work we compare a traditional Y-shaped array with a uniform circular (O-array) layout with the same number of elements. The O-array has less redundancy and thus yields more spatial frequency samples, leading to improved image quality. We investigate imaging of a set of conducting objects to show improved spurious signal reduction in the O-array.