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Realizing active metasurfaces with substantial tunability is important for many applications but remains challenging due to difficulties in dynamically tuning light-matter interactions at subwavelength scales. Here, we introduce reversible…

In conventional colocated multiple-input multiple-output (MIMO) radars, practical waveform constraints including peak-to-average power ratio, constant or bounded modulus lead to a significant performance reduction of transmit beampattern,…

Signal Processing · Electrical Eng. & Systems 2024-10-08 Shengyao Chen , Minghui He , Longyao Ran , Hongtao Li , Feng Xi , Sirui Tian , Zhong Liu

Reconfigurable Intelligent Surfaces (RISs) are promising and relatively low-cost tools for improving signal propagation in wireless communications. An RIS assists a base station in optimizing the channel and maximizing its capacity by…

Signal Processing · Electrical Eng. & Systems 2023-02-01 Andrey Sayanskiy , Andrey Belov , Ruslan Yafasov , Andrey Lyulyakin , Alexander Sherstobitov , Stanislav Glybovski , Vladimir Lyashev

We propose a new algorithm, for parameter estimation that is applicable to imaging using moving and synthetic aperture arrays. The new method results in higher resolution and more accurate estimation than commonly used methods when strong…

Instrumentation and Methods for Astrophysics · Physics 2010-08-31 Ronny Levanda , Amir Leshem

Diffraction microtomography in coherent light is foreseen as a promising technique to image transparent living samples in three dimensions without staining. Contrary to conventional microscopy with incoherent light, which gives…

Optics · Physics 2009-11-13 Stanislas Vertu , Jean-Jacques Delaunay , Olivier Haeberle

This letter attempts to design a surveillance scheme by adopting an active reconfigurable intelligent surface (RIS). Different from the conventional passive RIS, the active RIS could not only adjust the phase shift but also amplify the…

Information Theory · Computer Science 2024-10-28 Xinyue Hu , Yibo Yi , Kun Li , Hongwei Zhang , Caihong Kai

All-dielectric nanostructures have recently emerged as a promising alternative to plasmonic devices, as they also possess pronounced electric and magnetic resonances and allow effective light manipulation. In this work, we study optical…

Telescopes measuring cosmic microwave background (CMB) polarization on large angular scales require exquisite control of systematic errors to ensure the fidelity of the cosmological results. In particular, far-sidelobe contamination from…

A novel metasurface unit cell architecture is proposed to enable independent control of the reflection magnitude and phase at a desired operation frequency, while maintaining linear polarization of the incoming fields. The proposed…

Applied Physics · Physics 2020-09-29 Ahmed Z. Ashoor , Shulabh Gupta

The performance of antennas can severely deteriorate in the presence of adjacent electrically-large scatterers. In this work, we use a conducting hollow cylinder to shield the scatterer. The cylinder is shelled with single layer dielectric…

Optics · Physics 2023-08-24 Yi Zhang , Haiyan Fan , Yujie Zhang , Lixin Ran , Dexin Ye , Xudong Chen

Conventional active array radars often jointly design the transmit and receive beamforming for effectively suppressing interferences. To further promote the interference suppression performance, this paper introduces a reconfigurable…

Signal Processing · Electrical Eng. & Systems 2024-01-30 Shengyao Chen , Qi Feng , Longyao Ran , Feng Xi , Zhong Liu

We present an efficient method for the design of anomalous reflectors for acoustic waves. The approach is based on the fact that the anomalous reflector is actually a diffraction grating in which the amplitude of all the modes is negligible…

Applied Physics · Physics 2018-08-15 Daniel Torrent

We study the backward scatterings of plane waves by reciprocal scatterers and reveal that $n$-fold ($n\geq3$) rotation symmetry is sufficient to secure invariant backscattering for arbitrarily-polarized incident plane waves. It is further…

Optics · Physics 2021-01-27 Weijin Chen , Qingdong Yang , Yuntian Chen , Wei Liu

This paper provides a theoretical investigation of negative refraction and focusing of elastic guided waves in a free-standing plate with a step-like thickness change. Under certain conditions, a positive phase velocity (forward) Lamb mode…

Classical Physics · Physics 2019-01-02 François Legrand , Benoît Gérardin , Jérôme Laurent , Claire Prada , Alexandre Aubry

The smartphone, as a media device, should offer a large-size screen and fast data rates in a well-packed device. Emergent 5G technologies based on millimeter waves need efficiently radiating antennas integrated into devices whose bodies…

Applied Physics · Physics 2020-08-31 F. S. Cuesta , V. A. Lenets , A. Díaz-Rubio , A. Khripkov , S. A. Tretyakov

A spatially reconfigurable antenna arrays consists of an antenna array of finite length and fixed geometry which is displaced within a given area. Using these reconfigurable components, the performance of MIMO systems is remarkably improved…

Information Theory · Computer Science 2017-04-24 Saba Asaad , Ali Bereyhi , Mohammad Ali Sedaghat , Ralf R. Müller , Amir M. Rabiei

The existing phase shifter models adopted for reconfigurable intelligent surfaces (RISs) have ignored the electromagnetic (EM) waves propagation behavior, thus cannot reveal practical effects of RIS on wireless communication systems. Based…

Signal Processing · Electrical Eng. & Systems 2020-06-09 Weicong Chen , Lin Bai , Wankai Tang , Shi Jin , Wei Xiang Jiang , Tie Jun Cui

We present a novel antireflection approach utilizing planar metamaterials on dielectric surfaces. It consists of a split-ring resonator array and a metal mesh separated by a thin dielectric spacer. The coating dramatically reduces the…

Optics · Physics 2010-09-09 H. -T. Chen , J. Zhou , J. F. O'Hara , F. Chen , A. K. Azad , A. J. Taylor

Six-dimensional movable antenna (6DMA) is a promising solution for enhancing wireless network capacity through the adjustment of both three-dimensional (3D) positions and 3D rotations of distributed antenna surfaces. Previous works mainly…

Information Theory · Computer Science 2024-12-09 Haozhe Wang , Xiaodan Shao , Beixiong Zheng , Xiaoming Shi , Rui Zhang

Harnessing solar radiation pressure is key to transforming space exploration with multiple low cost sunlight propelled spacecraft to outer reaches of space. By controlling the direction of sunlight momentum transfer new missions and better…

Instrumentation and Methods for Astrophysics · Physics 2023-07-20 Tom Joly-Jehenne , Artur R. Davoyan
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