Publications associées à Tunable radiator for small satellite application

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

Mapping drivers of tropical forest loss with satellite image time series and machine learning

Devis Tuia, Jan Pisl, Marc Conrad Russwurm, Lloyd Haydn Hughes, Gaston Jean Lenczner, Jan Dirk Wegner

The rates of tropical deforestation remain high, resulting in carbon emissions, biodiversity loss, and impacts on local communities. To design effective policies to tackle this, it is necessary to know what the drivers behind deforestation are. Since drive ...

Iop Publishing Ltd2024

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

The imprint of galaxy mergers on satellite planes in a cosmological context

Oliver Müller

Flattened and kinematically correlated planes of dwarf satellite galaxies have been observed in the Local Volume. The slinging out of satellites during host galaxy mergers has been suggested as a formation mechanism for these peculiar structures. We statis ...

2023

Radiation Patterns of RF Wireless Devices Implanted in Small Animals: Unexpected Deformations Due to Body Resonance

Anja Skrivervik, Stéphanie Lacour, James Daniel Rosenthal, Mingxiang Gao, Kangling Wu, Zvonimir Sipus, German Augusto Ramirez Arroyave

One challenge in designing RF wireless bioelectronic devices is the impact of the interaction between electromagnetic waves and host body tissues on far-field wireless performance. In this paper, we investigate a peculiar phenomenon of implantable RF wirel ...

2023

A possible dwarf galaxy satellite-of-satellite problem in ?CDM

Yves Revaz, Nick Heesters

Dark matter clusters on all scales, and it is therefore expected that even substructure should host its own substructure. Using the Extragalactic Distance Database, we searched for dwarf-galaxy satellites of dwarf galaxies, that is, satellite-of-satellite ...

EDP SCIENCES S A2023

Analytic Approximation of In-Body Path Loss for Implanted Antennas

Anja Skrivervik, Mingxiang Gao, Zvonimir Sipus

Implantable bioelectronic devices predominantly use wireless links for communication and/or power transfer. When considering transmitting implanted antennas, electromagnetic radiation through biological media is highly attenuated, and previous work has sho ...

IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC2023

Hints of the Photonic Nature of the Electromagnetic Fields in Classical Electrodynamics

Farhad Rachidi-Haeri, Marcos Rubinstein

Several recent publications show that the electromagnetic radiation generated by transmitting antennas satisfy the following universal conditions: The time domain radiation fields satisfy the condition A ≥ h/4π ⇒ q ≥ e where A is the action of the radiatio ...

2023

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

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

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

Dual-Polarized SIW Slot Antenna Using ENZ Metamaterial for 5G and mmWave Applications

Romain Christophe Rémy Fleury, Amir Jafargholi

This paper presents a broadband dual-polarized substrate integrated waveguide (SIW) slot antenna. It is analytically shown that by decreasing the permittivity of a dielectricloaded slot antenna, the resulting bandwidth increases significantly, where the wi ...

IEEE2023

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

GNSS/INS Kalman Filter Integrity Monitoring with Uncertain Time Correlated Error Processes

Omar Garcia Crespillo

Safety-critical navigation applications require that estimation errors be reliably quantified and bounded. Over the last decade, significant effort has been put to guarantee a bounded position estimation by using Global Navigation Satellite Systems (GNSS) ...

EPFL2022

Australian Bushfires (2019-2020): Aerosol Optical Properties and Radiative Forcing

Romanos Foskinis

In the present study, we present the aerosol optical properties and radiative forcing (RF) of the tropospheric and stratospheric smoke layers, observed by the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) satellite, during the ...

2022

Ion temperature spectroscopic measurements in high rotation discharges by means of X-ray diagnostic at JET

Henri Weisen

Measurement of the X-ray spectra of the He-like Ni ions (Ni26+) and their dielectronic satellites (Ni25+, Ni24+, and Ni23+) plays a crucial role in determination of electronic and ion temperature of plasma in the JET device. Because n >= 3 satellites of Ni ...

2022

Civil war hinders crop production and threatens food security in Syria

Xi Li, Li Mi

Assessing the impact of violent conflict on Syrian agriculture is challenging given data limitations and attributability issues. Using satellite data at 30 m spatial resolution, we found that the extent of productive cropland showed greater interannual var ...

NATURE PORTFOLIO2022

EMC Impact of Disturbances Generated by Multiple Sources

Farhad Rachidi-Haeri, Marcos Rubinstein, Hamidreza Karami

In this paper, the impact of an increasing number of arbitrary electrical/electronic devices on the overall radiated emissions is investigated. Understanding and quantifying such an impact are prerequisites to the proper evaluation of electromagnetic compa ...

2022

The cis-lunar ecosystem — A systems model and scenarios of the resource industry and its impact

Jean-Paul Richard Kneib

Lunar resources is one of the many new putative business models that may transform space logistics. Yet it competes with Earth-based resources, in a complex trade-off involving both tech development & socioeconomic dynamics. This study models the size vs. ...

2021

Developing a UV climatology for public health purposes using satellite data

David Vernez, Athanasios Nenes

The effects of solar ultraviolet (UV) radiation on life on Earth differ greatly. While overexposure to UV rays is harmful, small amounts of exposure are necessary for the synthesis of Vitamin D and good health. To optimize individual exposure to solar UV, ...

2021