Metasurfaces have huge potentials to develop new type imaging systems due to their abilities of controlling electromagnetic waves. Here, we propose a new method for dual-sensor imaging based on cross-like holographic leaky-wave metasurfaces which are composed of hybrid isotropic and anisotropic surface impedance textures. The holographic leaky-wave radiations are generated by special impedance modulations of surface waves excited by the sensor ports. For one independent sensor, the main leaky-wave radiation beam can be scanned by frequency in one-dimensional space, while the frequency scanning in the orthogonal spatial dimension is accomplished by the other sensor. Thus, for a probed object, the imaging plane can be illuminated adequately to obtain the two-dimensional backward scattered fields by the dual-sensor for reconstructing the object. The relativity of beams under different frequencies is very low due to the frequency-scanning beam performance rather than the random beam radiations operated by frequency, and the multi-illuminations with low relativity are very appropriate for multi-mode imaging method with high resolution and anti- noise. Good reconstruction results are given to validate the proposed imaging method.
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http://dx.doi.org/10.1038/srep18170 | DOI Listing |
Sci Rep
January 2025
Department of Electrical Engineering, Iran University of Science and Technology, Tehran, 16846-1314, Iran.
The holographic technique is one of the simplest methods for designing antennas based on metasurface. This paper presents a spoof surface plasmon polariton (SSPP) leaky-wave antenna (LWA) based on the concept of impedance modulated metasurfaces by the anisotropic holographic technique. Instead of parasitic elements, anisotropic SSPP elements are exploited to achieve radiation with circular polarization.
View Article and Find Full Text PDFIn this paper, we present and design a tensor holographic metasurface (THMS) capable of radiating multiple beams with different polarizations in both forward and backward directions. The proposed THMS manipulates the fundamental TE mode surface waves (SWs) to produce bidirectional leaky-wave radiation using bilayer anisotropic metal patches. To achieve the independent control of the direction and polarization of bidirectional beams, the nature of the capacitive impedance element supporting TE mode SWs is exploited.
View Article and Find Full Text PDFSensors (Basel)
April 2024
Institute of Communications Engineering, National Yang Ming Chiao Tung University, Hsinchu 300093, Taiwan.
Recently, the community has seen a rise in interest and development regarding holographic antennas. The planar hologram is made of subwavelength metal patches printed on a grounded dielectric board, constituting flat metasurfaces. When a known reference wave is launched, the hologram produces a pencil beam towards a prescribed direction.
View Article and Find Full Text PDFSci Rep
May 2022
School of Electrical Engineering, Iran University of Science and Technology, Tehran, 1684613114, Iran.
Spatio-temporally modulated impedance surfaces can be good candidates for generation of radiating waves with arbitrary eigenstates by breaking momentum and energy conservations. Here, we present a theoretical framework based on the holographic technique and generalized Floquet-wave expansion to analyze spatio-temporally modulated impedance surfaces. The holographic technique estimates the required impedance distribution to achieve the desired momentum.
View Article and Find Full Text PDFSci Rep
May 2020
Institute of Communications Engineering, College of Electrical and Computer Engineering, National Chiao Tung University, Hsinchu, 30050, Taiwan.
This research reports a design method for synthesizing the binary meta-hologram pattern implemented in a leaky waveguide that can radiate the feeding signal toward a prescribed direction. In fact, the obtained pattern is not always a uniform array; it is an almost-periodic one. Statistical analysis of the radiation pattern for imperfect array is then conducted to demonstrate that radiating main-beam angle (ensemble average) is dominated by the average period of a non-uniform array subject to a small perturbation.
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