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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),
Millimeter-wave coplanar stripline power dividers
Bart Nauwelaers, Frank E. van Vliet, François le Chevalier, Chong Li, Lai Bun Lok, Ata Khalid, Vasileios Papageorgiou, James Grant, David R. S. Cumming
We present the design, fabrication, and measurement of a 2-way modified Wilkinson divider constructed in a coplanar geometry exhibiting ultra wideband isolation, transmission, and port matching in the millimeter-wave frequency range. The proposed divider replaces the lumped resistor in the conventional Wilkinson divider with two quarter-wave length transmission lines, a phase inverter, and two 2Z
Single-layer fully-planar extended-composite right-/left-handed transmission lines based on substrate integrated waveguides for dual-band and quad-band applications
Bart Nauwelaers, Frank E. van Vliet, François le Chevalier, Miguel Durán-Sindreu, Jordi Bonache, Ferran Martín, Tatsuo Itoh
The implementation and application of single-layer fully-planar extended-composite right-/left-handed transmission lines (E-CRLH TLs) in substrate-integrated waveguide (SIW) technology are presented. The multiband CRLH behavior of these artificial lines is explained by considering the lumped element equivalent circuit model. The potential of these lines for dual-band and quad-band applications is
Numerical and experimental characterization of a button-shaped miniaturized UHF antenna on magneto-dielectric substrate
Bart Nauwelaers, Frank E. van Vliet, François le Chevalier, Martino Aldrigo, Alessandra Costanzo, Diego Masotti, Carlo Baldisserri, Ioan Dumitru, Carmen Galassi
The design and characterization of a new broadband small patch antenna, based on an innovative magneto-dielectric material and suitable for wearable applications at 868 MHz, is presented. To reduce antenna dimensions, while preserving its radiation and matching performance, a barium-strontium hexaferrite BaSrFeO has been synthesized as the antenna substrate to achieve magnetic permeability double
Digital PA with voltage-mode topology using envelope delta-sigma modulation
Bart Nauwelaers, Frank E. van Vliet, François le Chevalier, Andreas Wentzel, Shinichi Hori, Makoto Hayakawa, Kazuaki Kunihiro, Wolfgang Heinrich
This paper reports on digital transmitter architecture for the 450 MHz band using an envelope delta-sigma modulator realized in CMOS and a voltage-mode class-S (VMCS) power amplifier (PA) based on GaN monolithic microwave integrated circuits (MMICs). The class-S PA is characterized for narrowband single-tone signals and a single- as well as a four-carrier downlink wideband code division multiple a
W-band active loads and switching front-end MMICs for radiometer calibration
Bart Nauwelaers, Frank E. van Vliet, François le Chevalier, Ernst Weissbrodt, Michael Schlechtweg, Oliver Ambacher, Ingmar Kallfass
A millimeter-wave monolithic integrated circuit consisting of a W-band (75?100 GHz) single-pole-five-throw (SP5T) switch and multiple internal active and passive loads for radiometer calibration was designed and manufactured in a low noise 50 nm GaAs metamorphic high electron mobility transistor technology. This highly compact and integrated front-end device for radiometer systems is capable of ul
Dielectric contrast measurements on biological substances with resonant microwave near-field sensors
Bart Nauwelaers, Frank E. van Vliet, François le Chevalier, Nora Haase, Arne F. Jacob
Resonant substrate integrated near-field sensors are used for characterization of aqueous solutions at three different frequencies. In addition, Chinese hamster ovary (CHO) cells in a culture medium are characterized with the same sensors. Different concentrations as well as different vital states of cell suspensions are examined. The complex permittivity of the samples is evaluated using a linear
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