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Wearable on-body millimeter-wave (mmWave) radars can provide obstacle detection and guidance for visually impaired individuals. The antennas, being a crucial component of these systems, must be lightweight, flexible, low-cost, and compact.…

In this article, a compact wideband circularly polarized antenna based on a miniaturized phase shifter with ultra-wideband operation is proposed. The proposed antenna is comprised of a pair of compact orthogonal ultra-wideband Vivaldi…

Optics · Physics 2025-10-21 Han-Jie Xu , Shi-Wei Qu

We demonstrate that reflectionless propagation of electromagnetic waves between two different materials can be achieved by designing an intermediate temporal medium, which can work in an ultra-wide frequency band. Such a temporal medium is…

Optics · Physics 2022-08-17 Yi Zhang , Liang Peng , Zhengjie Huang , Lixin Ran , Dexin Ye

We present a broadband and polarization-insensitive unidirectional imager that operates at the visible part of the spectrum, where image formation occurs in one direction while in the opposite direction, it is blocked. This approach is…

After decades of supremacy of the Titanium:Sapphire technology, Ytterbium-based high-order harmonic sources are emerging as an interesting alternative for experiments requiring high flux of ultrashort extreme ultraviolet (XUV) radiation. In…

Due to their large bandwidth, relatively low cost, and robust performance, UWB radio chips can be used for a wide variety of applications, including localization, communication, and radar. This article offers an exhaustive survey of recent…

This paper presents the design and fabrication of leaky-wave holograms with anisotropic properties, enabling circular polarization for single-beam radiation in desired directions. Tailored for future terrestrial networks like 5G, 6G, and…

Optics · Physics 2025-07-17 Hazhir Mohammadi , Amir Saman Nooramin , Homayoon Oraizi

Ultra-wide bandgap (UWBG) semiconductors promise to revolutionize power electronics, yet a fundamental understanding of their interfacial electronic structure has been hindered by the absence of direct experimental observation. Here, we…

An experimental investigation of sub-wavelength imaging by a wire medium slab is performed. A complex-shaped near field source is used in order to test imaging performance of the device. It is demonstrated that the ultimate bandwidth of…

Materials Science · Physics 2015-06-25 Pavel A. Belov , Yan Zhao , Sunil Sudhakaran , Akram Alomainy , Yang Hao

In this paper, we present a novel hemispherical antenna array (HAA) designed for high-altitude platform stations (HAPS). A significant limitation of traditional rectangular antenna arrays for HAPS is that their antenna elements are oriented…

Information Theory · Computer Science 2024-09-06 Omid Abbasi , Halim Yanikomeroglu , Georges Kaddoum

A simple but efficient approach for the synthesis of transmission-type wideband polarization converters is presented. The proposed configuration comprises multilayer metasurfaces including resonant particles which are progressively rotated…

Applied Physics · Physics 2020-12-11 Filippo Costa , Michele Borgese

A metamaterial composed of thin metallic strips as an efficient broadband absorber in the mid-infrared spectrum is investigated. Here the matching between dielectric and geometrical properties of the individual elements is critical to…

Optics · Physics 2022-05-24 Henrik Parsamyan , Hovhannes Haroyan , Khachatur Nerkararyan

In the medical fields, ultrasound detection is often performed with piezoelectric arrays that enable one to simultaneously map the acoustic fields at several positions. In this work, we develop a novel method for transforming a…

Signal Processing · Electrical Eng. & Systems 2020-05-26 Evgeny Hahamovich , Amir Rosenthal

A planar technology stripline-fed slot radiating element in transmission configuration is proposed. Its main advantages are the broad impedance bandwidth achieved and the property that it only radiates into half-space, which are obtained,…

Applied Physics · Physics 2018-10-09 Alberto Hernández-Escobar , Elena Abdo-Sánchez , Carlos Camacho-Peñalosa

Exploiting multi-antenna technologies for robust beamsteering to overcome the effects of blockage and beam misalignment is the key to providing seamless multi-Gbps connectivity in millimeter-wave (mm-wave) networks. In this paper, we…

Signal Processing · Electrical Eng. & Systems 2020-01-13 Lars Kuger , Aleksandar Ichkov , Petri Mähönen , Ljiljana Simić

We investigate synthesis of a large effective aperture using a sparse array of subarrays. We employ a multi-objective optimization framework for placement of subarrays within a prescribed area dictated by form factor constraints, trading…

Signal Processing · Electrical Eng. & Systems 2019-12-17 Anant Gupta , Upamanyu Madhow , Amin Arbabian , Ali Sadri

Highly ambitious initiatives aspire to propel a miniature spacecraft to a neighboring star within a human generation, leveraging the radiation pressure of lasers for propulsion. One of the main challenges to achieving this enormous feat is…

Optics · Physics 2025-01-16 Jin Chang , Wenye Ji , Xiong Yao , Arnold J. van Run , Simon Gröblacher

Dynamically switchable half-/quarter-wave plates have recently been the focus in the terahertz regime. Conventional design philosophy leads to multilayer metamaterials or narrowband metasurfaces. Here we propose a novel design philosophy…

Optics · Physics 2021-10-27 Xiaoqing Luo , Fangrong Hu , Guangyuan Li

Interference phenomena render tailoring propagation of electromagnetic waves by controlling phases of several scattering channels. Huygens element, being a representative example of this approach, allows enhancement of the scattering from…

Applied Physics · Physics 2020-09-23 Dmytro Vovchuk , Sergei Kosulnikov , Roman E. Noskov , Pavel Ginzburg

This paper presents a physics-consistent framework for bistatic sensing incorporating a 2-Dimensional (2D) waveguide-fed metasurface antenna array capable of realizing eXtremely-Large Multiple-Input Multiple-Output (XL MIMO) apertures. A…

Signal Processing · Electrical Eng. & Systems 2025-11-13 Ioannis Gavras , Panagiotis Gavriilidis , George C. Alexandropoulos