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Enhanced tunable performance of high -factor BaSrTiO film bulk acoustic wave resonators
Bart Nauwelaers, Frank E. van Vliet, François le Chevalier, Andrei Vorobiev, Spartak Gevorgian
Emerging intrinsically tunable film bulk acoustic wave(BAW) resonators allow the development of new generation reconfigurable and agile microwave circuits. In this paper, we demonstrate the enhancement of tunable performance of the high Q-factor BaSrTiO BAW ? solidly mounted resonators (BAW?SMR) by varying Ba concentration. The BaSrTiO BAW?SMR reveal tunability of series resonance frequency up to
Position estimation of lap joints for seam tracking applications at mm-wave frequencies
Bart Nauwelaers, Frank E. van Vliet, François le Chevalier, Jochen O. Schrattenecker, Andreas Haderer, Günther Reinthaler, Andreas Stelzer
In this paper, we present the results of using a frequency-stepped continuous-wave radar system to estimate the position of overlapping and electrically good conductive plates. We especially focus on polarimetric scattering effects caused by the step of a lap joint, which is a common welding-geometry. To model the step's contribution to the overall scattered signal, we use a two-dimensional combin
Miniature single-sideband subharmonically-pumped 60 GHz direct upconverter in a uniplanar GaAs pHEMT technology using inductive and capacitive loading techniques
Bart Nauwelaers, Frank E. van Vliet, François le Chevalier, Khelifa Hettak, Tyler N. Ross, Nazish Irfan, Gabriel Cormier, Mustapha C. E. Yagoub, Gilbert A. Morin, Jim S. Wight
This paper presents a novel, compact, single-sideband (SSB) subharmonically-pumped (SHP) direct upconverter developed in a uniplanar 0.18 ?m GaAs technology. A total of 100 MHz in-phase and quadrature signals directly modulate the second harmonic of a 30 GHz carrier signal, producing a 60.1 GHz output. Two pairs of antiparallel diodes reduce feed-through of the 30 GHz local oscillator (LO) signal
Toward highly scaled AlN/GaN-on-Silicon devices for millimeter wave applications
Bart Nauwelaers, Frank E. van Vliet, François le Chevalier, Farid Medjdoub, Yoann Tagro, Bertrand Grimbert, Damien Ducatteau, Nathalie Rolland
In this work, the possibility of achieving GaN-on-Si devices for millimeter wave applications operating at high bias is demonstrated. It is shown that highly scaled AlN/GaN-on-Si double heterostructure enables us to significantly improve electron confinement under high electric field as compared to single heterostructure while delivering high carrier density (>2 × 10 cm). Subsequently, trapping ef
Study of the noise processes in microwave oscillators based on passive optical resonators
Bart Nauwelaers, Frank E. van Vliet, François le Chevalier, Khaldoun Saleh, Pierre-Henri Merrer, Amel Ali-Slimane, Olivier Llopis, Gilles Cibiel
Two types of optoelectronic oscillators delivering high spectral purity microwave signals are presented in this paper. These oscillators use the Pound?Drever?Hall laser stabilization technique to lock the laser carrier onto two different types of passive optical resonators featuring high-quality factors: a fiber ring resonator (FRR) and a whispering gallery mode monocrystalline disk-shaped micro-r
Human motion classification using a particle filter approach: multiple model particle filtering applied to the micro-Doppler spectrum
Bart Nauwelaers, Frank E. van Vliet, François le Chevalier, Stephan Groot, Ronny Harmanny, Hans Driessen, Alexander Yarovoy
In this article, a novel motion model-based particle filter implementation is proposed to classify human motion and to estimate key state variables, such as motion type, i.e. running or walking, and the subject's height. Micro-Doppler spectrum is used as the observable information. The system and measurement models of human movements are built using three parameters (relative torso velocity, heigh
MEMS reconfigurable millimeter-wave surface for V-band rectangular-waveguide switch
Bart Nauwelaers, Frank E. van Vliet, François le Chevalier, Zargham Baghchehsaraei, Umer Shah, Jan Åberg, Göran Stemme, Joachim Oberhammer
This paper presents for the first time a novel concept of a microelectromechanical systems (MEMS) waveguide switch based on a reconfigurable surface, whose working principle is to block the wave propagation by short-circuiting the electrical field lines of the TE10 mode of a WR-12 rectangular waveguide. The reconfigurable surface is only 30 µm thick and consists of up to 1260 micromachined cantile
Multichannel interferometric SAR phase unwrapping using extended Kalman Smoother
Bart Nauwelaers, Frank E. van Vliet, François le Chevalier, Davide Chirico, Gilda Schirinzi
Phase unwrapping (PU) is one of the key processing steps in reconstructing the digital elevation model (DEM) of a scene from interferometric synthetic aperture radar (InSAR) data. The PU problem entails the estimation of an absolute phase from observation of its noisy principal (wrapped) values. Recently, PU approaches based on Kalman filtering have proved their efficacy in tackling the PU problem
A 24 GHz wideband monostatic FMCW radar system based on a single-channel SiGe bipolar transceiver chip
Bart Nauwelaers, Frank E. van Vliet, François le Chevalier, Christian Bredendiek, Nils Pohl, Timo Jaeschke, Sven Thomas, Klaus Aufinger, Attila Bilgic
In this paper a monostatic frequency-modulated continuous-wave (FMCW) radar system around a center frequency of 24 GHz with a wide tuning range of 8 GHz (?33%) is presented. It is based on a fully integrated single-channel SiGe transceiver chip. The chip architecture consists of a fundamental VCO, a receive mixer, a divider chain, and coupling/matching networks. All circuits, except for the divide
0.7?1.8 GHz multiband digital polar transmitter using watt-class current-mode class-D CMOS power amplifier and digital envelope modulation technique for reduced spurious emissions
Bart Nauwelaers, Frank E. van Vliet, François le Chevalier, Toshifumi Nakatani, Donald F. Kimball, Lawrence E. Larson, Peter M. Asbeck
A polar transmitter driven by digital input signals for envelope and phase is demonstrated, using a band-switching output resonator to achieve multiband operation. A new digital pulse width modulation algorithm is also shown to partially suppress spurious signals associated with the digital input envelope signal. The transmitter consists of a current-mode class-D (CMCD) CMOS power amplifier (PA),
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