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Bajaj, V. (author), Van de Plas, Raf (author), Wahls, S. (author)While probabilistic constellation shaping (PCS) enables rate and reach adaption with finer granularity [1] (Cho and Winzer, 2009), it imposes signal processing challenges at the receiver. Since the distribution of PCS-quadrature amplitude modulation (QAM) signals tends to be Gaussian, conventional blind polarization demultiplexing algorithms...journal article 2024
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Beikmirza, M.R. (author)The demand for faster mobile access and higher data throughput drives the evolution of wireless cellular communication, requiring larger modulation bandwidths and higher-order modulations and necessitating more efficient and flexible transmitter systems.<br/>Simultaneously, the advancements in nano-scale CMOS technologies have made transistors...doctoral thesis 2023
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Shen, Y. (author), Hoogelander, M. (author), Bootsman, R.J. (author), Alavi, S.M. (author), de Vreede, L.C.N. (author)A current-mode direct-digital RF modulator (DDRM)-based transmitter (TX) architecture is proposed in this article for energy-efficient wireless applications. To demonstrate its key principles, a 2×13 bit demonstrator is implemented in a 40-nm CMOS technology. This DDRM can operate standalone or as a driver for a common-gate (CG)/common-base ...journal article 2023
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Igea, Felipe (author), Cicirello, A. (author)Multi-modal distributions of some physics-based model parameters are often encountered in engineering due to different situations such as a change in some environmental conditions, and the presence of some types of damage and non-linearity. In statistical model updating, for locally identifiable parameters, it can be anticipated that multi...journal article 2023
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Shen, Y. (author), Bootsman, R.J. (author), Alavi, S.M. (author), de Vreede, L.C.N. (author)This article presents a wideband 2× 12 -bit direct-digital RF modulator (DDRM) operating in a 0.5-to-3-GHz band for 5G transmitters. The proposed digital Cartesian modulator features an advanced IQ-mapping technique to boost RF power by 3 dB and suppress the I/Q image. To verify the proposed concept, a 40-nm CMOS prototype is implemented...journal article 2022
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Mulder, W.A. (author)When solving the wave equation with finite elements, mass lumping allows for explicit time stepping, avoiding the cost of a lower-upper decomposition of the large sparse mass matrix. Mass lumping on the reference element amounts to numerical quadrature. The weights should be positive for stable time stepping and preserve numerical accuracy....journal article 2022
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Pashaeifar, M. (author), de Vreede, L.C.N. (author), Alavi, S.M. (author)This article presents a wideband energy-efficient transmitter (TX) for 5G mm-wave phased-array systems. It features an advanced double-quadrature direct upconverter (DQ-DUC) to improve its in-band linearity and spectral purity. The proposed TX architecture incorporates an efficiency-enhanced balanced power amplifier (EEBPA) that mitigates...journal article 2021
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Beikmirza, M.R. (author), Shen, Y. (author), de Vreede, L.C.N. (author), Alavi, S.M. (author)We present a wideband, 12-bit four-way Doherty Cartesian digital transmitter (DTX) featuring an innovative 50%-LO signed I/Q interleaved up-conversion technique that enables close to perfect orthogonal I/Q summation. The DTX incorporates a compact four-way lumped-element Doherty power combining network to enhance its average efficiency at...journal article 2021
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van den Bos, L.M.M. (author), Sanderse, B. (author)A novel mathematical framework is derived for the addition of nodes to univariate and interpolatory quadrature rules. The framework is based on the geometrical interpretation of the Vandermonde matrix describing the relation between the nodes and the weights and can be used to determine all nodes that can be added to an interpolatory...journal article 2021
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van den Bos, L.M.M. (author), Bierbooms, W.A.A.M. (author), Alexandre, Armando (author), Sanderse, Benjamin (author), van Bussel, G.J.W. (author)A novel approach is proposed to reduce, compared with the conventional binning approach, the large number of aeroelastic code evaluations that are necessary to obtain equivalent loads acting on wind turbines. These loads describe the effect of long-term environmental variability on the fatigue loads of a horizontal-axis wind turbine. In...journal article 2020
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van den Bos, L.M.M. (author), Sanderse, B. (author), Bierbooms, W.A.A.M. (author)A novel method is proposed to infer Bayesian predictions of computationally expensive models. The method is based on the construction of quadrature rules, which are well-suited for approximating the weighted integrals occurring in Bayesian prediction. The novel idea is to construct a sequence of nested quadrature rules with positive weights...journal article 2020
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van den Bos, L.M.M. (author), Sanderse, Benjamin (author), Bierbooms, W.A.A.M. (author), van Bussel, G.J.W. (author)For the purpose of uncertainty propagation a new quadrature rule technique is proposed that has positive weights, has high degree, and is constructed using only samples that describe the probability distribution of the uncertain parameters. Moreover, nodes can be added to the quadrature rule, resulting in a sequence of nested rules. The rule...journal article 2020
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Moghadasi Barazandeh, Mohsen (author)Particle-laden internal turbulent flows are very commonplace, for example, in petrochemical flow lines, oil wells and so on. From an engineering view point, modelling such flows in a 3D or even 2D fashion may not be reasonable in terms of computational cost, especially when the flow domain is sufficiently long, and a large number of grid cells...master thesis 2019
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Gao, Z. (author), Hu, Yizhe (author), Siriburanon, Teerachot (author), Staszewski, R.B. (author)This paper proposes a mm-wave quadrature frequency generator using injection-locked harmonic extractors (HEs) incorporated with quadrature class-F oscillators. While maintaining high output levels at 28 GHz, the utilization of injection locking technique improves the effective quality ($Q$)-factor and helps to achieve a fundamental harmonic...conference paper 2019
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Geevers, S. (author), Mulder, W.A. (author), van der Vegt, J.J.W. (author)We present new and efficient quadrature rules for computing the stiffness matrices of mass-lumped tetrahedral elements for wave propagation modeling. These quadrature rules allow for a more efficient implementation of the mass-lumped finite element method and can handle materials that are heterogeneous within the element without loss of the...journal article 2019
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van Nieuwpoort, Ruben (author)The finite element method (FEM) is an ubiquitous method for the analysis of boundary value problems. Specifically, it can be used to find approximations to solutions of boundary value problems on a specific domain...master thesis 2017
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Madadi, I. (author)There are nowadays strong business and technical demands to integrate radio- frequency (RF) receivers (RX) into a complete system-on-chip (SoC) realized in scaled digital processes technology. As a consequence, the RF circuitry has to function well in face of reduced power supply ( V DD ) while the CMOS device threshold voltage ( V th ) stays...doctoral thesis 2015
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Tohidian, M. (author)In a radio-frequency (RF) system-on-chip (SoC), a digital baseband/application processor, which occupies most of the silicon area, determines the SoC fabrication process technology and voltage supply. The rest of the circuitry, including RF front-end and frequency synthesizer, must then adopt the chosen process technology, i.e., presently low...doctoral thesis 2015
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Tohidian, M. (author), Ahmadi-Mehr, S.A.R. (author), Staszewski, R.B. (author)A new quadrature oscillator topology is proposed, which arranges four low-Q series LC tanks in a ring structure driven by inverters operating in class-D. With a very small area of 0.007 mm^2 that is comparable to conventional ring oscillators, this oscillator has 7–20 dB better phase noise FoM of 177 dB. It is widely tunable for nearly an octave...journal article 2015
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Alavi, S.M. (author)Due to the severe cost pressure of consumer electronics, a migration to an advanced nanoscale CMOS processes, which is primarily developed for fast and low-power digital circuits operating at low supply voltages, is necessary, but it forces wireless RF transceivers to exploit more and more digital circuitry. These basic CMOS properties tend to...doctoral thesis 2014
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