Searched for: subject%3A%22Antennas%22
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Tadolini, Cesare (author)
The analysis of integrated front ends operated in the high-frequency regimes is addressed in this work. The analysis of these problems has been a critical bottleneck for decades due to the difficulties arising in adopting full-wave techniques. Assuming, as typical at lower frequencies, that the structures are planar leads to the inaccurate...
master thesis 2024
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Zhang, H. (author)
In recent decades, dielectric lens antennas have been more and more adopted and developed for sensing and imaging applications at sub-millimeter (sub-mm) wavelengths because they can achieve high gain while keeping their physical size and weight acceptable at these wavelengths. More recently, as low-loss and low-cost lens materials have become...
doctoral thesis 2024
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Aslan, Y. (author), Roederer, A.G. (author), Fonseca, Nelson J.G. (author), Angeletti, Piero (author), Yarovoy, Alexander (author)
An innovative reconfigurable beamforming network concept for multiple high-gain agile and mutually zero-forced beam generation is proposed. Four-port couplers and variable phase shifters are used to synthesize the network. A 2 beam by 7 element beam former is designed and fabricated as proof of concept. A static scenario with the two beams...
conference paper 2024
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Locatelli, A. (author), Alvarez-Perez, Jose Luis (author), Yarovoy, Alexander (author)
Multi-path propagation over asphalt road surfaces at automotive radar frequencies is studied. A new expression for the reflection coefficient from asphalt which takes into account asphalt surface roughness is proposed. The classic two-ray method to take into account the multi-path is improved using antenna radiation patterns and the antenna tilt...
conference paper 2024
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Hehenberger, S.P. (author), Caizzone, Stefano (author), Yarovoy, Alexander (author)
The utilization of low-cost hybrid additive manufacturing equipment for creating a fully integrated patch antenna system is demonstrated. A miniaturized stacked dual-band patch antenna for GNSS applications with integrated feed, amplifier, matching, and bias network is considered. Design and manufacturing challenges due to the peculiarities of...
conference paper 2024
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Onat, N.B. (author), Yarovoy, Alexander (author), Aslan, Y. (author)
The sunflower array topology concept is introduced, for the first time, to the constrained infinitesimal dipole modeling (IDM) technique to increase the computational efficiency and reduce the modeling errors. The concept is applied to embedded element pattern predictions via matrix inversion. A novel study on the impact of the type and...
conference paper 2024
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Hu, Weiya (author), Coco Martin, C.M. (author), Cavallo, D. (author)
A semi-analytical method is presented for the design of gradient index (GRIN) flat lenses. Closed-form expressions are derived to define the refractive index distribution of the lens, for several cases: collimating lenses with on-axis feed, collimating lenses with off-axis feed, lenses converting spherical wavefronts with different...
journal article 2024
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Hernandez-Burgos, Sergi (author), Gibert, Ferran (author), Broquetas, Antoni (author), Kleinherenbrink, M. (author), De la Cruz, Adrian Flores (author), Gomez-Olive, Adria (author), Garcia-Mondejar, Albert (author), Aparici, Monica Roca i. (author)
The 2-D frequency-based omega-K method is known to be a suitable algorithm for fully focused SAR (FF-SAR) radar altimeter processors, as its computational efficiency is much higher than equivalent time-based alternatives without much performance degradation. In this article, we provide a closed-form description of a 2-D frequency-domain omega...
journal article 2024
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Wang, Ranran (author), Zhang, Jun (author), Lu, Yijun (author), Ren, S. (author), Huang, Jiandong (author)
The design of geopolymer concrete must meet more stringent requirements for the landscape, so understanding and designing geopolymer concrete with a higher compressive strength challenging. In the performance prediction of geopolymer concrete compressive strength, machine learning models have the advantage of being more accurate and faster....
journal article 2024
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Stumpf, Martin (author), Antonini, Giulio (author), Lager, I.E. (author)
The transient electromagnetic (EM) excitation of a narrow slot in a perfectly electrically conducting (PEC) screen that separates two homogeneous dielectric halfspaces, a simplified model of a typical feeding structure of leaky lens antennas, is analyzed numerically in the time domain (TD). The problem is formulated using the TD reciprocity...
journal article 2024
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Ozzola, R. (author), Neto, A. (author), Imberg, Ulrik (author), Cavallo, D. (author)
We present a dual-polarized connected array of slots with an artificial dielectric layer (ADL) radome for mobile communication applications operating in the sub-6 GHz and the upper 6 GHz bands of 5G. The radiating slots are combined with two interchangeable ADL radomes with different thicknesses, targeting the bands 6-8 and 2-8 GHz,...
journal article 2024
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Zhang, H. (author), Llombart, Nuria (author), Bueno Lopez, J. (author), Freni, Angelo (author)
Photoconductive antennas (PCAs) are promising candidates for sensing and imaging applications. In recent years, our group has investigated their properties under pulsed laser illumination in transmission using a time-domain (TD) Norton equivalent circuit. Here, we extend this analysis to the link between a photoconductive source and a...
journal article 2024
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Gu, Junhong (author), Stumpf, Martin (author), Neto, A. (author), Lager, I.E. (author)
A strictly causal numerical study of the pulsed operation of a weakly dispersive, leaky wave (LW) antenna is presented. The intricacies at the forefront of the electromagnetic (EM) field radiated from a gap-fed slot in a perfectly electrically conducting (PEC) sheet are evidenced for the first time. The radical effect of a free-space gap...
journal article 2024
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Mohammadkarimi, M. (author), Leus, G.J.T. (author), Rajan, R.T. (author)
A new method for joint ranging and Phase Offset (PO) estimation of multiple drones/aircrafts is proposed in this paper. The proposed method employs the superimposed uncoordinated Automatic Dependent Surveillance-Broadcast (ADS-B) packets broadcasted by drones/aircrafts for joint range and PO estimation. It jointly estimates range and PO prior...
journal article 2024
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Dabironezare, Shahab Oddin (author), Nair, A. (author), Neto, A. (author), Llombart, Nuria (author)
The use of lens arrays in (sub)-millimeter sensing and communication applications will enable the development of integrated antenna front-ends with multiple independent beams as well as dynamic scanning capabilities. In applications such as MIMO communications, interferometric arrays, and Tx/Rx duplexing capabilities, a key parameter is the...
journal article 2024
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Aslan, Y. (author), Roederer, A.G. (author)
This paper in the roadmap presents the research trends on antenna systems for Satellite Communication terminals. To address the challenges posed by this application in terms of wide fractional bandwidth and large field-of-view, several antenna concepts and architectures are being investigated, which can be grouped in three main technology areas:...
conference paper 2024
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Tan, Junyao (author)
This master thesis explores the capacity of MIMO arrays for communication in the radiative near field through antenna design. This research applies an in-house MATLAB model based on free space Green’s function to calculate the channel matrix, revealing the potential increase of capacity through the use of incoherent arrays with directive...
master thesis 2023
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Beijnen, Laurens (author)
Distributed feeding in photo-conducting antennas (PCAs) leads to simple optical designs, less prone to overheating, as well to terahertz (THz) antennas that can operate non-dispersively over wide bandwidths. However, the efficient analysis of pulsed PCAs was so far limited to architectures characterized by feeds small with respect to the THz...
master thesis 2023
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Zhang, Muhan (author)
Recently, there has been an increasing demand for security in public places. As a result, non-destructive and fast millimetre-wave and submillimetre-wave imaging systems have gained more and more attention.<br/>This project is based on Concealed Objects Stand-off Real-Time Imaging for Security (CONSORTIS), which is a European next-generation...
master thesis 2023
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Kooij, Roeland (author)
As the world is getting used to 5G technology, 6G is already on the horizon. With the ultimate goal of very low latency communication and Tbps data rates, 6G supports new wireless technologies such as virtual and augmented reality and autonomous driving. In this new generation of wireless communication, high frequencies up to 100 GHz are used...
master thesis 2023
Searched for: subject%3A%22Antennas%22
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