Publications related to Radio-frequency engineering

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

Integrated Wireless Power, Data Communication, and Thermal Sensing System for Autonomous Multisite Brain Implants

Implanted medical devices (IMDs) have been widely developed to support the monitoring and recording of biological data inside the body or brain. Wirelessly powered IMDs, a subset of implantable electronics, have been proposed to eliminate the limitations r ...

EPFL2024

Architecture for integrated RF photonic downconversion of electronic signals

Tobias Kippenberg, Junqiu Liu

Electronic analog to digital converters (ADCs) are run-ning up against the well-known bit depth versus bandwidth trade off. Towards this end, radio frequency (RF) photonic-enhanced ADCs have been the subject of interest for some time. Optical frequency com ...

Optica Publishing Group2023

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

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

Plasma sputtering of biased electrodes in an oblique magnetic field

Stefano Alberti, Ivo Furno, Alessandro Geraldini

The surface erosion of biased electrodes immersed in a radio frequency (RF) plasma was investigated in oblique magnetic fields ranging from 0.1 T to 3.5 T. The plasma potential and density in the vicinity of the biased electrode have been measured using an ...

IOP Publishing Ltd2023

H I constraints from the cross-correlation of eBOSS galaxies and Green Bank Telescope intensity maps

Jean-Paul Richard Kneib

We present the joint analysis of Neutral Hydrogen (H I) Intensity Mapping observations with three galaxy samples: the Luminous Red Galaxy (LRG) and Emission Line Galaxy (ELG) samples from the eBOSS survey, and the WiggleZ Dark Energy Survey sample. The H I ...

OXFORD UNIV PRESS2022

Wireless Powering Efficiency of Deep-Body Implantable Devices

Anja Skrivervik, Denys Nikolayev, Zvonimir Sipus, Mingxiang Gao, Erdem Cil

The wireless power transfer (WPT) efficiency to implanted bioelectronic devices is constrained by several frequency-dependent physical mechanisms. Recent works have developed several mathematical formulations to understand these mechanisms and predict the ...

Institute of Electrical and Electronics Engineers2022

Time-Varying Components for Enhancing Wireless Transfer of Power and Information

Romain Christophe Rémy Fleury, Mohammad Sajjad Mirmoosa, Xuchen Wang

Temporal modulation of components of electromagnetic systems provides an exceptional opportunity to engineer the response of those systems in a desired fashion, both in the time and frequency domains. For engineering time-modulated systems, one needs to th ...

American Physical Society (APS)2021

ICRF modelling in 2D and 3D magnetic configurations using a hot plasma model

Wilfred Anthony Cooper, Jonathan Graves, Mike Machielsen

The generation of energetic trapped ions is important for experiments investigating their confinement in 3D magnetic fields, for plasma heating, for studies into unwanted drive of instabilities, and improved transport regimes. An effective way to generate ...

2021

Dipole-Fed Rectangular Dielectric Resonator Antennas for Magnetic Resonance Imaging at 7 T: The Impact of Quasi-Transverse Electric Modes on Transmit Field Distribution

Rolf Gruetter, Daniel Wenz

Shortened dipole antennas based on rectangular dielectric blocks play an important role in ultrahigh field magnetic resonance imaging (UHF-MRI) radio frequency (RF) coil design. However, the generally assumed direct contact with the subject is difficult to ...

2021

Improving Railway Track Coverage with mmWave Bridges: A Measurement Campaign

Andreas Peter Burg, Ruben Merz, Adrian Schumacher

Bringing cellular capacity into modern trains is challenging because they act as Faraday cages. Building a radio frequency (RF) corridor along the railway tracks ensures a high signal-to-noise ratio and limits handovers. However, building such RF corridors ...

ASSOC COMPUTING MACHINERY2021

Physics and applications of three-ion ICRF scenarios for fusion research

Henri Weisen, Mikhail Maslov, Javier García Hernández, Samuele Mazzi

This paper summarizes the physical principles behind the novel three-ion scenarios using radio frequency waves in the ion cyclotron range of frequencies (ICRF). We discuss how to transform mode conversion electron heating into a new flexible ICRF technique ...

2021

Blind as a bat: spatial perception without sight

Frederike Dümbgen

Among our five senses, we rely mostly on audition and vision to perceive an environment. Our ears are able to detect stimuli from all directions, especially from obstructed and far-away objects. Even in smoke, harsh weather conditions, or at night â situ ...

EPFL2021

Heterostructure design and field management in III-N high-electron mobility electronic devices

Catherine Erine

III-N family of materials has offered multiple groundbreaking technologies in the field of optoelectronics and high-power radio-frequency (RF) devices. Blue light-emitting diodes (LEDs) have revolutionized low-energy lighting. Gallium nitride (GaN) RF mark ...

EPFL2021

Opportunities and challenges of 2D materials in back-end-of-line interconnect scaling

Benjamin Aaron Helfrecht, Alejandro Strachan

As the challenges in continued scaling of the integrated circuit technology escalate every generation, there is an urgent need to find viable solutions for both the front-end-of-line (transistors) and the back-end-of-line (interconnects). For the interconn ...

AMER INST PHYSICS2020

Advanced Monitoring Systems Based on Battery-Less Asset Tracking Modules Energized through RF Wireless Power Transfer

Catherine Dehollain, Roberto La Rosa

Asset tracking involving accurate location and transportation data is highly suited to wireless sensor networks (WSNs) featuring battery-less nodes that can be deployed in virtually any environment and require little or no maintenance. In response to the g ...

2020

Optimal Frequency of Operation and Radiation Efficiency Limitations of Implantable Antennas

Anja Skrivervik, Denys Nikolayev, Zvonimir Sipus

Fundamental limits on radiation performance of implantable antennas serve as the design quality gauge, facilitate the choice of the antenna type, and provide simple design rules to maximize the radiation performance. This study obtains the limits using two ...

IEEE2020

Photonic microwave generation in the X- and K-band using integrated soliton microcombs

Tobias Kippenberg, Rui Ning Wang, Junqiu Liu, Maxim Karpov, Hairun Guo, Erwan Guillaume Albert Lucas, Arslan Sajid Raja, Jijun He

Microwave photonic technologies, which upshift the carrier into the optical domain, have facilitated the generation and processing of ultra-wideband electronic signals at vastly reduced fractional bandwidths. For microwave photonic applications such as rad ...

Nature Publishing Group2020

Temperature dependence of reconfigurable bandstop filters using vanadium dioxide switches

Mihai Adrian Ionescu, Matteo Cavalieri, Andrei Müller

In this Letter, we report and investigate the temperature dependency of various radio frequency (RF) parameters for a fabricated reconfigurable bandstop filter with vanadium dioxide (VO2) switches measured up to 55 GHz. Here, the insulator-to-metal (ITM) a ...

AIP American Institute of Physics2020