Publications related to Acoustic rat-race coupler and its applications in non-reciprocal systems

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

The 2024 Magnonics Roadmap

Dirk Grundler, Benedetta Flebus, Ping Che, Wei Zhang, Thomas Yu, Qi Wang

Magnonics is a research field that has gained an increasing interest in both the fundamental and applied sciences in recent years. This field aims to explore and functionalize collective spin excitations in magnetically ordered materials for modern informa ...

2024

Biomaterial devices on Arecanut palm leaf for microwave applications

Anja Skrivervik, Sujith Raman

This paper presents an investigation on the possibility of arecanut palm leaf as a biomaterial substrate for various microwave devices such as transmission lines, antenna, filter and a radio frequency identification device (RFID). The dielectric properties ...

IEEE2023

Resonators with tailored optical path by cascaded-mode conversions

Ileana-Cristina Benea-Chelmus, Marco Piccardo

Optical resonators enable the generation, manipulation, and storage of electromagnetic waves. The physics underlying their operation is determined by the interference of electromagnetic waves, giving rise to the resonance spectrum. This mechanism causes th ...

Nature Portfolio2023

Time-Domain Integration of Broadband Terahertz Pulses via Tapered Two-Wire Waveguide

Alessandro Tomasino

In this work, we report on the implementation of a time-domain integrator device operating on arbitrary broadband Terahertz (THz) pulses. This analog signal-processing functionality is implemented by employing a two-wire waveguide (TWWG) variant, based on ...

IEEE2023

Nanomechanical resonators with low dissipation for quantum optomechanics

Alberto Beccari

Fields of technology as diverse as microwave filter construction, characterization of material interfaces with atomic precision, and detection of gravitational waves from astronomical sources employ mechanical resonators at their core. The utility of mecha ...

EPFL2023

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

Numerical and experimental investigations of a microwave interferometer for the negative ion source SPIDER

Ivo Furno, Rémy Jacquier, Riccardo Agnello

The electron density close to the extraction grids and the co-extracted electrons represent a crucial issue when operating negative ion sources for fusion reactors. An excessive electron density in the plasma expansion region can indeed inhibit the negativ ...

IOP Publishing Ltd2023

4-Port Microstrip planar resonator for multiband microwave material characterization applications

Anja Skrivervik, Sujith Raman

Planar microstrip resonators suitable for material characterization application are presented in this paper. The prototype consists of three resonators fed through four ports in a planar dielectric substrate without any additional resonators. The resonator ...

IEEE2022

Inflight Microwave Drying Process of Micro-droplets for High Resolution 3D printing

Kwanghoon Choi

A new Additive-Manufacturing (AM) or 3D printing concept is proposed to improve the printing resolution for metal additive manufacturing in the frame of the SFA-AM project, Powder Focusing for Beam-Induced Laser 3D Printing. The project aims to transport s ...

EPFL2022

Effects of resonator geometry and substrate stiffness on the tunability of a deformable microwave metasurface

Taha Goudarzi, Romain Christophe Rémy Fleury, Rayehe Karimi Mahabadi

Tunable metasurfaces can shift their resonant frequency through different approaches, one of which is applying mechanical deformations. Here, we show the effects of two key factors on the tunability of deformable metasurfaces; the resonator geometry and su ...

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

Unconventional time-bandwidth performance of resonant cavities with nonreciprocal coupling

Camille Sophie Brès, Davide Grassani, Ivan Cardea, Kosmas Tsakmakidis

The time-bandwidth limit is a mathematical tenet that affects all reciprocal resonators, stating that the product of the spectral bandwidth that can couple into a resonant system and its characteristic energy decay time is always equal to 1. Here, we devel ...

2021

A Cryogenic Broadband Sub-1-dB NF CMOS Low Noise Amplifier for Quantum Applications

Edoardo Charbon, Andrea Ruffino, Yatao Peng

A cryogenic broadband low noise amplifier (LNA) for quantum applications based on a standard 40-nm CMOS technology is reported. The LNA specifications are derived from the readout of semiconductor quantum bits at 4.2 K, whose quantum information signals ar ...

2021

Probing unconventional performance of fiber resonators: light storage, generation and manipulation

Ivan Cardea

This thesis aims at investigating the performance of figure-9 (figure-of-nine) optical fiber resonators as a practical solution for light storage, light generation and manipulation. The first part of the thesis focuses on a theoretical and experimental stu ...

EPFL2021

Towards a N77 Electroacoustic Filter Using Thin Films of Crystalline Y-cut Lithium Niobate

Victor Plessky, Luis Guillermo Villanueva Torrijo, Soumya Yandrapalli

This paper presents the use of a novel type of resonators made of a thin membrane of Y-cut Lithium Niobate that has an array of interdigitated electrodes on the top, and a floating metal on the bottom. Each electrode gives rise to a quasi-independent reson ...

IEEE2021

Sommerfeld Integrals and Their Relation to the Development of Planar Microwave Devices

Krzysztof Michalski, Juan Ramon Mosig

This paper deals with the mathematical expressions called Sommerfeld integrals. Introduced by A. Sommerfeld in 1909, they are mathematically equivalent to inverse Hankel transforms. The original historical goal of these integrals was to provide an accurate ...

Ieee-Inst Electrical Electronics Engineers Inc2021

Subwavelength Metawaveguide Filters and Metaports

Maliheh Khatibi Moghaddam, Romain Christophe Rémy Fleury

This paper proposes an alternative technique for the design of miniaturized waveguide filters based on locally resonant metamaterials (LRMs). We implement ultrasmall metamaterial filters (metafilters) by exploiting a subwavelength (sub-λ) guiding mechanism ...

American Physical Society (APS)2021

Prototype mitre bends of the ex-vessel waveguide system for the ITER upper launcher: Thermal hydraulic simulations and experiments with off-center mm-wave beams

René Chavan, Timothy Goodman, Matteo Vagnoni, Anastasia Xydou, Humberto Torreblanca Quiroz

On ITER, long pulse gyrotrons are required as a power source for electron cyclotron heating (ECH) and current drive (CD). The microwaves are guided from the gyrotrons, which are placed far from the Tokamak, into the plasma by transmission lines (TLs) and a ...

2021

Integration concept of an Electron Cyclotron System in DEMO

René Chavan, Minh Quang Tran, Hartmut Zohm, Konstantinos Avramidis

The pre-conceptual layout for an electron cyclotron system (ECS) in DEMO is described. The present DEMO ECS considers only equatorial ports for both plasma heating and neoclassical tearing mode (NTM) control. This differs from ITER, where four launchers in ...

2021