Sharif Digital Repository

This article focuses on analyzing the aliasing artifact in millimeter-wave imaging systems, with a special focus on multistatic arrays. The current framework to analyze the behavior of multistatic structures is based on the effective aperture concept. Based on this framework, an equivalent monostatic array, approximating the position of each transmitter-receiver pair by its midpoint, is used to quantify the response and efficiency of the system. Although this framework helps to simplify the study of the complex characteristics of multistatic arrays, it suffers from vital deficiencies. Especially, it fails to describe the aliasing artifacts, seen in the image of some sparse multistatic... 

In this brief, an imaging methodology for mono-static millimeter-wave systems is introduced. When the measured object hologram is piece-wise smooth with sharp boundaries, both low-pass and high-pass components are present in a transform domain. Nevertheless, the edges are sparse in transform domain with respect to the image dimensions. It is shown that the down-sampling of the hologram with an appropriate rate determined by the sparsity level, includes the adequate information of all components for image reconstruction. Using random samples, an algorithm is proposed to recover all the sparse components, iteratively. Simulation results illustrate that a high-resolution recovery can be... 

In this article, we propose a software-hardware system to improve the quality of image recovery in millimeter-wave (MMW) imaging systems, which aims to benefit from copolarization and cross-polarization scatterings from the target. The proposed dual-polarized antenna array structures consist of two orthogonal subarrays with the same phase center, where each subarray is comprised of 2 imes 1 or 4 imes 1 rectangular edge fed patches and the optimized ground defects. These compact structures, which support radiation of two orthogonal linear polarizations, are designed on a single-layer board using crossover technique. The dual-polarized scattering from the target is captured by the orthogonal...