W-Band Compressive Imaging System Based on the Flat Metamaterial

This paper designs a W-band compressive imaging system using a flat metamaterial aperture to perform high-resolution imaging without mechanical scanning or costly phased arrays. The proposed system employs a 2D metamaterial-based parallel plate waveguide integrated with cELC elements, excited by frequencydiverse radiation patterns. By leveraging compressive sensing principles, the system reconstructs sparse scenes through a measurement model, which is considered as a linear inverse problem and regularized using prior sparsity constraints. Key metrics, including SVD spectra, MSE, and effective sparsity, are analyzed to optimize crucial parameters such as aperture density, bandwidth, element quality factor, and spatial distribution. Trade-off studies demonstrate quasi-linear performance dependence on frequency points and bandwidth, along with minimal sensitivity to element density. An experimental validation is conducted using a synthesized aperture with 43 receiver positions and a single transceiver. The obtained results demonstrates high consistency between the simulations and measured results, though target specularity limits the full resolution. Furthermore, effective sparsity is considered as a unified metric for system evaluation, demonstrating the feasibility of W-band metamaterial-based compressive imaging. This approach provides a cost-effective solution for millimeter-scale resolution in security, aerospace, and industrial applications, allowing to balance the performance and practical implementation constraints.