Development of Fast Fourier-Compatible Image Reconstruction for 3D Near-Field Bistatic Microwave Imaging With Dynamic Metasurface Antennas

The emerging technology of dynamic metasurface antennas (DMAs) offers a promising solution to revolutionize future wireless communications by reducing hardware costs, physical size and power consumption. Especially in the field of radar imaging, DMAs can be used as an effective alternative platform for modern computational imaging; because they can simplify the physical hardware architecture and increase the data acquisition rate. Fourier transform (FT)-based scene image reconstruction techniques are known as cost-effective computing solutions for the imaging system processing unit. However, due to the physical layer compression in DMAs and the fact that they do not produce uniform radiation patterns, the information provided by them is not compatible with Fourier-based techniques and cannot be applied directly. In this article, we first introduce a 3D near-field bistatic imaging approach using two one-dimensional (1D) DMAs as a panel-to-panel model in a Mills Cross structure. Then, based on the introduced mathematical model, we derive a Fourier-based algorithm for the image reconstruction problem. The proposed algorithm consists of five main steps: (i) pre-processing (to transfer the data provided by the transmitter and receiver DMAs to a set of equivalent spatial measurements), (ii) applying FTs to the transferred signal, (iii) filtering in the Fourier domain, (iv) a simplified interpolation, and (v) applying a 3D inverse FT to retrieve scene information. The results of numerical simulations confirm the satisfactory performance of the proposed approach.