AUTHOR=Han Jiaqi , Li Long , Tian Shuncheng , Ma Xiangjin , Feng Qiang , Liu Haixia , Zhao Yu , Liao Guisheng TITLE=Frequency-Diverse Holographic Metasurface Antenna for Near-Field Microwave Computational Imaging JOURNAL=Frontiers in Materials VOLUME=8 YEAR=2021 URL=https://www.frontiersin.org/journals/materials/articles/10.3389/fmats.2021.766889 DOI=10.3389/fmats.2021.766889 ISSN=2296-8016 ABSTRACT=

This article presents a holographic metasurface antenna with stochastically distributed surface impedance, which produces randomly frequency-diverse radiation patterns. Low mutual coherence electric field patterns generated by the holographic metasurface antenna can cover the K-band from 18 to 26 GHz with 0.1 GHz intervals. By utilizing the frequency-diverse holographic metasurface (FDHM) antenna, we build a near-field microwave computational imaging system based on reflected signals in the frequency domain. A standard horn antenna is adopted to acquire frequency domain signals radiated from the proposed FDHM antenna. A detail imaging restoration process is presented, and the desired targets are correctly reconstructed using the 81 frequency-diverse patterns through full-wave simulation studies. Compressed sensing technique and iterative shrinkage/thresholding algorithms are applied for the imaging reconstruction. The achieved compressive ratio of this computational imaging system on the physical layer is 30:1.