Publications associées à Code for project entitled "study on conformal antennas, proof of concept prototype for a UAV"

A mmWave Low Complexity and Low-Cost Super Wideband Dual-Polarized Aperture Coupled Antenna for 5G Applications

Advanced antenna system (AAS) is a viable option for 5G millimeter-wave (mmWave) applications. AAS single element is favored to be dual-polarized, wideband, high gain, and compact in order to be utilized for 5G antenna arrays. In this paper, a low complexi ...

Ieee-Inst Electrical Electronics Engineers Inc2024

Enabling Wide Bandwidth in Substrate-Integrated Waveguide Slot Antennas by Using Low-Index Metamaterials

Romain Christophe Rémy Fleury, Jalaledin Tayebpour, Amir Jafargholi

This paper presents a solution to overcome the inherently limited bandwidth of substrate-integrated waveguide (SIW) slot antennas. It is analytically shown that by decreasing the permittivity of a dielectric loaded slot antenna, the resulting bandwidth inc ...

American Physical Society (APS)2024

Circularly polarized planar antenna with axially symmetric beamwidth reconfigurability

Anja Skrivervik, Ismael Vico Triviño, Hannes Bartle

This contribution presents the design of a compact circularly polarized antenna featuring beamwidth reconfiguration in both the horizontal and vertical planes. The observed radiation patterns in each of the reconfigurable states present axial symmetry and ...

IEEE2023

Microstrip patch antennas with broad beamwidth

Ismael Vico Triviño

Microstrip antennas offer a broad set of advantages such as low profile, light weight, easy fabrication and low cost. As these are desirable or even critical for a broad range of applications, there has been a large interest for these antennas in the anten ...

EPFL2023

Toward Metantennas: Metamaterial-Based Antennas for Wireless Communications

Yuanyan Su

Antennas have historically been the most common electromagnetic (EM) technology for wireless communication systems. Antenna as hardware is entirely dependent on the EM properties of the materials used, mostly related to the permittivity and permeability. I ...

Ieee-Inst Electrical Electronics Engineers Inc2023

Evaluation of a New Process for the Additive Manufacturing of Metal Antennas

German Augusto Ramirez Arroyave

This paper presents a new process for additively manufacturing purely metallic antennas based on Fused Deposition Modeling (FDM), with a proprietary filament developed using a hot extrusion method and composed by a mix of rounded shape copper powders with ...

2023

Small antennas with broad beamwidth integrated on a drone enclosed in a protective structure

Anja Skrivervik, Ismael Vico Triviño

In this paper, we analyze the integration of small antennas in a drone protected by a conductive structure. They must be light and resistant to provide high collision resilience, which is critical for drones flown indoors and in complex environments. To ac ...

IEEE2023

Universal and adaptive methods for robust stochastic optimization

Ali Kavis

Within the context of contemporary machine learning problems, efficiency of optimization process depends on the properties of the model and the nature of the data available, which poses a significant problem as the complexity of either increases ad infinit ...

EPFL2023

Analysis of Non-Canonical Body-Conformal Arrays with Polarization Decomposition

Anja Skrivervik, Denys Nikolayev

Conformal phased arrays can be found in many applications due to their ability to fit tridimensional surfaces and, thanks to their scanning performance, can excel planar arrays. However, most of the previously proposed analysis methods can be applied only ...

IEEE2023

Safe Zeroth-Order Convex Optimization Using Quadratic Local Approximations

Baiwei Guo, Giancarlo Ferrari Trecate, Yuning Jiang, Maryam Kamgarpour

We address black-box convex optimization problems, where the objective and constraint functions are not explicitly known but can be sampled within the feasible set. The challenge is thus to generate a sequence of feasible points converging towards an optim ...

IEEE2023

Augmented Lagrangian Methods for Provable and Scalable Machine Learning

Mehmet Fatih Sahin

Non-convex constrained optimization problems have become a powerful framework for modeling a wide range of machine learning problems, with applications in k-means clustering, large- scale semidefinite programs (SDPs), and various other tasks. As the perfor ...

EPFL2023

A Spatial Branch and Bound Algorithm for Continuous Pricing with Advanced Discrete Choice Demand Modeling

Michel Bierlaire

In this paper, we present a spatial branch and bound algorithm to tackle the continuous pricing problem, where demand is captured by an advanced discrete choice model (DCM). Advanced DCMs, like mixed logit or latent class models, are capable of modeling de ...

2023

Multi-antenna 3D pattern design for millimeter-wave vehicular communications

German Augusto Ramirez Arroyave

The transformation of the automotive industry towards ubiquitous connection of vehicles with all kind of external agents (V2X) motivates the use of a wide range of frequencies for several applications. Millimeter-wave (mmWave) connectivity represents a par ...

2022

Enhancing the beamwidth of low profile single-fed microstrip antennas using parasitic elements

Anja Skrivervik, Ismael Vico Triviño

In this paper we present a technique to broaden the beamwidth of conventional patch microstrip antennas by using parasitic elements. This technique allows to keep the main advantages of microstrip antennas while increasing their beamwidth. We provide guide ...

IEEE2022

Estimation of Charge Transfer During Long Continuing Currents in Natural Downward Flashes Using Single‐Station E‐Field Measurements

Farhad Rachidi-Haeri, Hannes Kohlmann, Wolfgang Schulz

The amount of charge transferred to ground during long continuing currents in natural downward flashes can be obtained either through direct current measurements or using remote electromagnetic fields, if direct measurements are not feasible. In this study ...

2022

Predicting in Uncertain Environments: Methods for Robust Machine Learning

Paul Thierry Yves Rolland

One of the main goal of Artificial Intelligence is to develop models capable of providing valuable predictions in real-world environments. In particular, Machine Learning (ML) seeks to design such models by learning from examples coming from this same envi ...

EPFL2022

How to improve the efficiency of a traditional dissolution dynamic nuclear polarization (dDNP) apparatus: Design and performance of a fluid path compatible dDNP/LOD-ESR probe

Jean-Noël Hyacinthe, Andrea Capozzi, Thanh Phong Kevin Lê

Dissolution Dynamic Nuclear Polarization (dDNP) was invented almost twenty years ago. Ever since, hardware advancement has observed 2 trends: the quest for DNP at higher field and, more recently, the development of cryogen free polarizers. Despite the DNP ...

Academic Press Inc - Elsevier Science2022

Minkowski's Loop Fractal Antenna Dedicated to Sixth Generation (6G) Communication

Maria-Alexandra Paun

In this study, we will discuss the engineering construction of a special sixth generation (6G) antenna, based on the fractal called Minkowski's loop. The antenna has the shape of this known fractal, set at four iterations, to obtain maximum performance. Th ...

MDPI2022

Optical metasurfaces: synthesis, nanofabrication, and colorful applications

Hsiang-Chu Wang

In this thesis, we mainly utilize silver to construct the meta-atoms. Although suffering from easily oxidized, its excellent lossless property throughout the visible range makes it suitable for study. When preserved properly, silver-made metasurfaces can s ...

EPFL2022

An Accelerated First-Order Method for Non-convex Optimization on Manifolds

Nicolas Boumal, Christopher Arnold Criscitiello

We describe the first gradient methods on Riemannian manifolds to achieve accelerated rates in the non-convex case. Under Lipschitz assumptions on the Riemannian gradient and Hessian of the cost function, these methods find approximate first-order critical ...

SPRINGER2022