Publications associées à Radiodiffusion

Magnetism of Single Surface Adsorbed Atoms Studied with Radio-Frequency STM

This thesis investigates the magnetic properties of single atoms and molecules adsorbed on thin magnesium oxide decoupling layers, grown on a silver single crystal. To address these systems experimentally, we use a low temperature scanning tunneling micros ...

EPFL2024

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

Fast ion generation with ICRF waves and beams in the Wendelstein 7-X stellarator

Mike Machielsen

The largest operating stellarator, Wendelstein 7-X, is of the quasi-isodynamic type. For this design to scale up to a fusion reactor, several criteria must be met, one of them being good fast ion confinement. The latter still has to be tested experimentall ...

EPFL2023

Biodegradable materials as sensitive coatings for humidity sensing in S-band microwave frequencies

Danick Briand, Nicolas Francis Fumeaux, James Alec Pierce Bourely, Leticia de Sousa, Oleksandr Vorobyov

Worldwide, electronic waste represents the fastest-growing stream of waste. With an increasing number of connected devices, passive and eco-friendly environmental sensing solutions need to be developed. Wireless passive devices for RFID and sensing exist, ...

2023

Intelligent RF System for Ultra Low Power Spectrum Sensing with Machine Learning

Naci Pekçokgüler

The crowdedness of the RF spectrum constitutes problems in communication, however it also accommodates large amount of useful information. This information can be used to determine existing signals and operating contexts. However, spectrum condition varies ...

EPFL2024

A KL Divergence-Based Loss for In Vivo Ultrafast Ultrasound Image Enhancement with Deep Learning

Jean-Philippe Thiran, Roser Vinals Terres

Ultrafast ultrasound imaging, characterized by high frame rates, generates low-quality images. Convolutional neural networks (CNNs) have demonstrated great potential to enhance image quality without compromising the frame rate. However, CNNs have been most ...

2023

A New Analytical Approximation of the Fluid Antenna System Channel

Malek Khammassi

Fluid antenna systems (FAS) are an emerging technology that promises a significant diversity gain even in the smallest spaces. It consists of a freely moving antenna in a small linear space to pick up the strongest received signal. Previous works in the li ...

Ieee-Inst Electrical Electronics Engineers Inc2023

Microwave Metalens Antennas

Yuanyan Su, Teng Li

Recently, there has been growing interest in the use of metamaterial (MTM)-based lenses, also known as metalenses, as innovative antenna technology. Increasingly widespread applications of metalenses in modern microwave communication and sensing systems ha ...

IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC2023

Frontiers in the Application of RF Vacuum Electronics

Timothy Goodman

The application of radio frequency (RF) vacuum electronics for the betterment of the human condition began soon after the invention of the first vacuum tubes in the 1920s and has not stopped since. Today, microwave vacuum devices are powering important app ...

2023

Data Downloaded via Parachute from a NASA Super-Pressure Balloon

David Richard Harvey, Mathilde Jauzac, Richard Massey, Lun Li

In April 2023, the superBIT telescope was lifted to the Earth's stratosphere by a helium-filled super-pressure balloon to acquire astronomical imaging from above (99.5% of) the Earth's atmosphere. It was launched from New Zealand and then, for 40 days, cir ...

MDPI2023

Radiation Performance of Antennas Implanted in Small Animals for Neuroengineering

Anja Skrivervik, Stéphanie Lacour, Mingxiang Gao, Zvonimir Sipus, Kangling Wu, James Daniel Rosenthal

Wireless data communication could improve the performance and reliability of biomedical implants used in fundamental neuroscience research by removing infection-prone transcutaneous cabling. The small size of common research animals like mice and rodents, ...

IEEE2023

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

Reduced material loss in thin-film lithium niobate waveguides

Tobias Kippenberg, Mikhail Churaev, Zihan Li, Guanhao Huang, Di Zhu

Thin-film lithium niobate has shown promise for scalable applications ranging from single-photon sources to high-bandwidth data communication systems. Realization of the next generation high-performance classical and quantum devices, however, requires much ...

AIP Publishing2022

Cellular Fronthauling for Data Capacity Increase in Underserved Spaces

Adrian Schumacher

The increase in wireless data traffic continues and is a product of several factors. First, new technologies and capabilities enable new use cases for which new products emerge. Then, with the growing user adoption over time, the data traffic is further in ...

EPFL2022

Subthreshold VO2 vertical switches for large-bandwidth millimeter-wave and sub-terahertz detection

Mihai Adrian Ionescu, Ali Gilani, Daesung Park, Fatemeh Qaderi Rahaqi

n-linear impedance characteristics of VO2 offer solutions to highly sensitive radio-frequency (RF), millimeterwave (mm-wave), and terahertz (THz) detectors. We demonstrate high-speed broadband sensibility of miniaturized VO2 switches by utilizing the nonli ...

IEEE2022

Nanoplasma-based Millimiter-wave Modulators on a Single Metal Layer

Elison de Nazareth Matioli, Mohammad Samizadeh Nikooytabalvandani

Fundamental constraints imposing power-frequency trade-offs in conventional electronics have stimulated research on alternative technologies for millimeter-wave and sub-millimeter-wave applications. In this work, we use the picosecond threshold firing of n ...

Institute of Electrical and Electronics Engineers2022

Enhanced radio-frequency performance of niobium films on copper substrates deposited by high power impulse magnetron sputtering

Fabio Avino

We present a study of radio frequency properties of niobium films deposited on copper by two different approaches based on High Power Impulse Magnetron Sputtering, namely with a DC voltage biased substrate and with bipolar target voltage. Such approaches e ...

2022

Millimeter-wave to near-terahertz sensors based on reversible insulator-to-metal phase transition in Vanadium dioxide

Fatemeh Qaderi Rahaqi

Millimeter-wave (mm-wave) and terahertz (THz) detection has opened a significant research direction in imaging, sensing, spectroscopy, and ultrafast wireless communication. The sensitivity of the phase transition to electromagnetic waves in Vanadium dioxid ...

EPFL2022

Increasing Cellular Network Energy Efficiency for Railway Corridors

Andreas Peter Burg, Ruben Merz, Adrian Schumacher

Modern trains act as Faraday cages making it challenging to provide high cellular data capacities to passengers. A solution is the deployment of linear cells along railway tracks, forming a cellular corridor. To provide a sufficiently high data capacity, m ...

IEEE2022

New Technologies to Enhance the Figures-of-Merit of GaN Power Devices

Luca Nela

Gallium Nitride (GaN) has enabled groundbreaking developments in the field of optoelectronics and radio frequency communication. More recently, GaN devices for power conversion applications have demonstrated excellent potential. Thanks to Gallium Nitride w ...

EPFL2022