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We present a method for full spatial phase and amplitude control of a laser beam using a twisted nematic liquid crystal display combined with a spatial filter. By spatial filtering we combine four neighboring pixels into one superpixel. At…

Optics · Physics 2009-11-13 E. G. van Putten , I. M. Vellekoop , A. P. Mosk

This paper proposes a novel multiple-access framework, termed the phased ultra massive antenna array (PUMA), which exploits the distinctive spatial flexibility of fluid antenna systems (FAS) at the user equipment (UE). Building upon fluid…

Information Theory · Computer Science 2026-05-07 Hanjiang Hong , Kai-Kit Wong , Xusheng Zhu , Chenguang Rao , Dazhi He , Hyundong Shin

Atmospheric turbulence is a serious problem for ground-based interferometers. It places tight limits on both sensitivity and measurement precision. Phase referencing is a method to overcome these limitations via the use of a bright…

Astrophysics · Physics 2015-06-24 Benjamin F. Lane , Matthew W. Muterspaugh

The Segment Anything Model (SAM), introduced to the computer vision community by Meta in April 2023, is a groundbreaking tool that allows automated segmentation of objects in images based on prompts such as text, clicks, or bounding boxes.…

Computer Vision and Pattern Recognition · Computer Science 2024-08-13 Athulya Sundaresan Geetha , Muhammad Hussain

High-frequency wideband cellular communications over mmWave and sub-THz offer the opportunity for high data rates. However, it also presents high path loss, resulting in limited coverage. High-gain beamforming from the antenna array is…

Information Theory · Computer Science 2024-08-14 Ozlem Yildiz , Ahmad AlAmmouri , Jianhua Mo , Younghan Nam , Elza Erkip , Jianzhong , Zhang

We present an approach for improving spatial frequency sampling in active incoherent millimeter-wave (AIM) imaging systems using frequency diversity. AIM imaging relies on active transmission of spatio-temporally incoherent signals to…

Signal Processing · Electrical Eng. & Systems 2025-03-12 Jorge R. Colon-Berrios , Jeffrey A. Nanzer

The modular design of planar phased array antennas with hexagonal apertures is addressed by means of innovative diamond-shaped tiling techniques. Both tiling configuration and subarray coefficients are optimized to fit user-defined…

Signal Processing · Electrical Eng. & Systems 2022-01-02 P. Rocca , N. Anselmi , A. Polo , A. Massa

We use a simple setup based on an infinite planar slab gain medium with no mirrors to explore the possibility of realizing a recently discovered resonance effect related to the mathematical concept of spectral singularity. In particular we…

Optics · Physics 2010-07-13 Ali Mostafazadeh

Optical phased arrays (OPAs) which beam-steer in 2D have so far been unable to pack emitting elements at $\lambda/2$ spacing, leading to grating lobes which limit the field-of-view, introduce signal ambiguity, and reduce optical efficiency.…

Applied Physics · Physics 2020-08-25 Nathan Dostart , Bohan Zhang , Michael Brand , Daniel Feldkhun , Miloš Popović , Kelvin Wagner

Acoustic phased arrays are capable of steering and focusing a beam of sound via selective coordination of the spatial distribution of phase angles between multiple sound emitters. Constrained by the principle of reciprocity, conventional…

Applied Physics · Physics 2021-11-16 R. Adlakha , M. Moghaddaszadeh , M. A. Attarzadeh , A. Aref , M. Nouh

We propose an uplink massive MIMO system using an array of holographic metasurfaces as a sector antenna. The antenna consists of a set of rectangular waveguide-fed metasurfaces combined along the elevation direction into a planar aperture,…

Signal Processing · Electrical Eng. & Systems 2021-08-31 Insang Yoo , David R. Smith

Fluid antenna system (FAS)/movable antenna (MA) has emerged as a promising technology to fully exploit the spatial degrees of freedom (DoFs). In this paper, we propose a new rotatable antenna (RA) model, as a simplified implementation of…

Information Theory · Computer Science 2025-02-28 Qingjie Wu , Beixiong Zheng , Tiantian Ma , Rui Zhang

This paper presents key performance metrics for near-field communication and sensing systems and their scaling behavior as a function of the antenna array aperture. Analytical expressions are derived for several standard array geometries to…

Signal Processing · Electrical Eng. & Systems 2026-01-09 Marcin Wachowiak , André Bourdoux , Sofie Pollin

The effective Kerr nonlinearity of hollow-core kagome-style photonic crystal fiber (PCF) filled with argon gas increases over 100 times when the pressure is increased from 1 to 150 bar, reaching 15 % of that of bulk silica glass, while the…

The performance of holographic multiple-input multiple-output (MIMO) communications, employing two-dimensional (2-D) planar antenna arrays, is typically compromised by finite degrees-of-freedom (DOF) stemming from limited array size. The…

An innovative strategy for the design of low-profile wide-angle impedance matching (WAIM) superstrates to active return loss (ARL) stability of scanned microstrip-printed periodic phased arrays (PPAs) is presented. Towards this end, an…

Signal Processing · Electrical Eng. & Systems 2021-04-23 G. Oliveri , A. Polo , M. Salucci , G. Gottardi , A. Massa , A. Massa

Two transformation-optics inspired flat lenses are used to build up an optical system capable to transpose an area surrounding the object focal point in a magnified area surrounding the image focal point. The object and image focal points…

Optics · Physics 2018-08-10 Mircea Giloan , Robert Gutt

A design methodology for planar loaded antenna arrays is proposed to synthesize a perfect anomalous reflection into an arbitrary direction by optimizing the scattering characteristics of passively loaded array antennas. It is based on…

Applied Physics · Physics 2024-09-26 Sravan K. R. Vuyyuru , Risto Valkonen , Sergei A. Tretyakov , Do-Hoon Kwon

Metal nanowires and nanoparticles that facilitate surface plasmons are of contemporary interest in nanophotonics, thermoplasmonics and optoelectronics. They facilitate not only subwavelength light propagation and localization capabilities,…

Optics · Physics 2020-08-05 Sunny Tiwari , Chetna Taneja , G V Pavan Kumar

Large array-based transmission uses the combination of a massive number of antenna elements and clever precoder designs to achieve array gain and spatially multiplex different users. These precoders require linear front-ends, and more…

Signal Processing · Electrical Eng. & Systems 2021-10-18 François Rottenberg , Gilles Callebaut , Liesbet Van der Perre
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