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Related papers: A Model for Phased Array Feed

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Filters are key devices in optical systems and are usually applied to signal suppression or selection based on their amplitude frequency responses. Different from amplitude filtering, an all-pass filter (APF) is a unique type of filter that…

Optics · Physics 2019-05-27 Lu Xu , Yuan Yu , Xiaolong Liu , Xuewen Shu , Xinliang Zhang

In this paper, we show empirical evidence on how to construct the optimal feature selection or input representation used by the input layer of a feedforward neural network for the propose of forecasting spatial-temporal signals. The…

Neural and Evolutionary Computing · Computer Science 2019-07-24 Eurico Covas , Emmanouil Benetos

We give a probabilistic interpretation of sampling theory of graph signals. To do this, we first define a generative model for the data using a pairwise Gaussian random field (GRF) which depends on the graph. We show that, under certain…

Machine Learning · Computer Science 2015-03-24 Akshay Gadde , Antonio Ortega

A method for modeling a reflector antenna system with a wideband phased array feed is presented and used to study the effects of the number of active antenna elements and associated receiving channels on the sensitivity of the system.…

Instrumentation and Methods for Astrophysics · Physics 2011-10-21 Oleg Iupikov

We investigate the ellipticity of the point-spread function (PSF) produced by imaging an unresolved source with a telescope, subject to the effects of atmospheric turbulence. It is important to quantify these effects in order to understand…

Astrophysics · Physics 2011-02-11 W. H. de Vries , S. S. Olivier , S. J. Asztalos , L. J. Rosenberg , K. L. Baker

We present a universal and rigorous approach to study difference frequency generation in the terahertz domain, keeping the number of degrees of freedom to a minimum, through the definition of a suitable figure of merit. The proposed method…

The narrowband and far-field assumption in conventional wireless system design leads to a mismatch with the optimal beamforming required for wideband and near-field systems. This discrepancy is exacerbated for larger apertures and…

Signal Processing · Electrical Eng. & Systems 2022-07-01 Nitish Deshpande , Miguel R. Castellanos , Saeed R. Khosravirad , Jinfeng Du , Harish Viswanathan , Robert W. Heath

Most existing antenna array-based source localization methods rely on fixed-position arrays (FPAs) and strict assumptions about source field conditions (near-field or far-field), which limits their effectiveness in complex, dynamic…

Standard phase-stepping algorithms (PSAs) estimate the measuring phase of linear carrier temporal-fringes with respect to a linear-reference. Linear-carrier fringes are normally obtained using feedback, closed-loop, optical phase-shifting…

Signal Processing · Electrical Eng. & Systems 2019-03-27 Manuel Servin , Moises Padilla , Ivan Choque , Sotero Ordones

Traditional antenna pattern measurements involve minimizing the impact of multipath propagation in the measurement environment. In contrast, this work introduces a measurement approach that uses rather than mitigates multipath propagation.…

Signal Processing · Electrical Eng. & Systems 2025-07-08 Daniel D. Stancil

Millimeter-wave networks have already been successfully rolled out in many countries and now the research direction heads toward new technologies and standards to enable Tbps rates for future sixth-generation (6G) wireless communication…

Information Theory · Computer Science 2023-11-03 Leila Tlebaldiyeva , Sultangali Arzykulov , Khaled M. Rabie , Xingwang Li , Galymzhan Nauryzbayev

Holographic Metasurface Transceivers (HMTs) are emerging as cost-effective substitutes to large antenna arrays for beamforming in Millimeter and TeraHertz wave communication. However, to achieve desired channel gains through beamforming in…

Signal Processing · Electrical Eng. & Systems 2024-01-12 Debamita Ghosh , Manjesh Kumar Hanawal , Nikola Zlatanova

Dependability modeling and evaluation is aimed at investigating that a system performs its function correctly in time. A usual way to achieve a high reliability, is to design redundant systems that contain several replicas of the same…

Artificial Intelligence · Computer Science 2012-12-12 Andrea Bobbio , Stefania Montani , Luigi Portinale

In order to efficiently image a non-absorbing sample (a phase object), dedicated phase contrast optics are required. Typically, these optics are designed with the assumption that the sample is weakly scattering, implying a linear relation…

Optics · Physics 2020-10-22 Stewart Koppell , Mark Kasevich

Real-world time-series datasets often violate the assumptions of standard supervised learning for forecasting -- their distributions evolve over time, rendering the conventional training and model selection procedures suboptimal. In this…

Machine Learning · Computer Science 2022-09-27 Sercan O. Arik , Nathanael C. Yoder , Tomas Pfister

This paper demonstrates the advantages of aperiodic arrays in multi-user multiple-input multiple-output systems for future mobile communication applications. We propose a novel aperiodic array synthesis method which account for the…

Signal Processing · Electrical Eng. & Systems 2018-08-28 C. Bencivenni , A. A. Glazunov , R. Maaskant , M. V. Ivashina

Here we propose a route to the high-Q perfect absorption of light by introducing the concept of a Fano anti-laser. Based on the drastic spectral variation of the optical phase in a Fano-resonant system, a spectral singularity for…

Optics · Physics 2015-07-30 Sunkyu Yu , Xianji Piao , Jiho Hong , Namkyoo Park

Transforming the instrumental photometry of ground-based telescopes into a calibrated physical flux in a well-defined passband is a major challenge in astronomy. Along with the intrinsic instrumental difference between telescopes sharing…

Instrumentation and Methods for Astrophysics · Physics 2025-07-08 S. Garrappa , E. O. Ofek , S. Ben-Ami , D. Polishook , A. Gal-Yam , Y. Shvartzvald , A. Krassilchtchikov , R. Konno , E. Segre , Y. M. Shani , Y. Sofer-Rimalt , M. Engel , A. Blumenzweig

Accurately rendering the appearance of fabrics is challenging, due to their complex 3D microstructures and specialized optical properties. If we model the geometry and optics of fabrics down to the fiber level, we can achieve unprecedented…

Predictable Feature Analysis (PFA) (Richthofer, Wiskott, ICMLA 2015) is an algorithm that performs dimensionality reduction on high dimensional input signal. It extracts those subsignals that are most predictable according to a certain…

Machine Learning · Computer Science 2017-12-05 Stefan Richthofer , Laurenz Wiskott