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Search results for: compact components
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Low-cost multi-objective design of compact microwave structures using domain patching
PublicationA good compromise between size and electrical performance is an important design consideration for compact microwave structures. Comprehensive information about size/performance trade-offs can be obtained through multi-objective optimization. Due to considerable electromagnetic (EM) cross-couplings in highly compressed layouts, the design process has to be conducted at the level of high-fidelity EM analysis which is computationally...
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Compact Dual-Polarized Corrugated Horn Antenna for Satellite Communications
PublicationIn this paper, a structure and design procedure of a novel compact dual-polarized corrugated horn antenna with high gain and a stable phase center for satellite communication is presented. The antenna incorporates an Ortho-Mode Transducer (OMT), a mode converter, and a corrugated structure. The compact OMT section is designed to be fed by standard WR-75 waveguides. The proposed compact design utilizes only ten corrugated slots...
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EM-Driven Multi-Objective Design of Impedance Transformers By Pareto Ranking Bisection Algorithm
PublicationIn the paper, the problem of fast multi-objective optimization of compact impedance matching transformers is addressed by utilizing a novel Pareto ranking bisection algorithm. It approximates the Pareto front by dividing line segments connecting the designs found in the previous iterations, and refining the obtained candidate solutions by means of poll-type search involving Pareto ranking. The final Pareto set is obtained using...
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Expedited two-objective dimension scaling of compact microwave passives using surrogate models
PublicationGeometry scaling of compact microwave structures is a challenging problem because of complex relationships between the physical dimensions and electrical characteristics, mostly caused by considerable cross-couplings in densely arranged layouts. Here, a procedure for expedited dimension scaling of compact microwave couplers with respect to two independent criteria has been presented. Our approach involves inverse surrogate models...
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Inverse modeling for fast design optimization of small-size rat-race couplers incorporating compact cells
PublicationIn the paper, a framework for computationally-efficient design optimization of compact rat-race couplers (RRCs) is discussed. A class of hybrid RRCs with variable operating conditions is investigated, whose size reduction is obtained by replacing ordinary transmission lines with compact microstrip resonant cells (CMRCs). Our approach employs a bottom-up design strategy leading to the development of compact RRCs through rapid design...
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Rheological and compressive strength (ultrasonic pulse method) properties of cement pastes containing iron oxide (Fe3O4) nanoparticles
Open Research DataRheological data of cement pastes containing different replacement levels of cement with iron oxide nanoparticles deterimined using MCR 301 (Anton Paar) stress-imposed rheometer, equipped with calibrated helicoidal geometry
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A Hopf type theorem for equivariant local maps
PublicationWe study otopy classes of equivariant local maps and prove a Hopf type theorem for such maps in the case of a real finite-dimensional orthogonal representation of a compact Lie group.
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Fast multi-criterial statistical analysis and design optimization of compact microwave couplers
Publication—A rapid statistical analysis and yield estimation of compact microwave couplers involving multiple performance parameters has been presented. The analysis is realized using a fast surrogate model representing appropriate characteristic points of the coupler response. Because of less nonlinear dependence of the characteristic points on the structure geometry (compared to the original response, i.e., S-parameters vs. frequency),...
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Ultra-Compact Self-Quadruplexing Microfluidically Frequency Reconfigurable Slot Antenna Using Half-Mode SIW
PublicationIn this brief, the design of an ultra-compact self-quadruplexing frequency reconfigurable antenna (SQFRA) utilizing a half-mode substrate-integrated waveguide (HMSIW) and microfluidic channels is discussed. Four HMSIW cavities fed by four microstrip lines and slots are used to construct a highly compact antenna. The microstrip feedings to the HMSIW cavities are applied in such a way that the proposed antenna exhibits self-quadruplexing...
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A robust design of a numerically demanding compact rat-race coupler
PublicationA fast and accurate design procedure of a computationally expensive microwave circuit has been presented step-by-step and experimentally validated on the basis of a compact rat-race coupler (RRC) comprising slow-wave resonant structures (SWRSs). The final compact RRC solution has been obtained by means of a sequential optimization scheme exploiting the implicit space mapping (ISM) algorithm. A well-suited surrogate optimization...
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Size Reduction of Microwave Couplers by EM-Driven Optimization
PublicationThis work addresses simulation-driven design optimization of compact microwave couplers that explicitly aims at circuit footprint area reduction. The penalty function approach allows us to minimize the area of the circuit while ensuring a proper power division between the output ports and providing a sufficient bandwidth with respect to return loss and isolation around the operating frequency. Computational cost of the optimization...
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Novel topology of compact coplanar waveguide resonant cell low-pass filter
PublicationIn this study, a novel pseudoelliptic function low-pass filter (LPF) constituted by a compact coplanar waveguide resonant cell has been designed and manufactured. The lumped-element seven-pole prototype has been adequately realized by using complementary perturbations located both in signal line and ground plane metallization. The fabricated uniplanar LPF offers a compact size of 5.6 x 9.8 mm2, return loss better than 26 dB over...
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Accurate Computation of IGBT Junction Temperature in PLECS
PublicationIn the article, a new method to improve the accuracy of the insulated-gate bipolar transistor (IGBT) junction temperature computations in the piecewise linear electrical circuit simulation (PLECS) software is proposed and described in detail. This method allows computing the IGBT junction temperature using a nonlinear compact thermal model of this device in PLECS. In the method, a nonlinear compact thermal model of the IGBT is...
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Rapid surrogate-assisted statistical analysis of compact microstrip couplers
PublicationIn this paper, a technique for low-cost statistical analysis and yield estimation of compact microwave couplers has been presented. The analysis is executed at the level of a fast surrogate model representing selected characteristic points of the coupler response that are critical to determine satisfaction/violation of the prescribed design specifications. Because of less nonlinear dependence of the characteristic points on geometry...
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Simulation-driven design of compact ultra-wideband antenna structures
PublicationPurpose–The purpose of this paper is to investigate strategies and algorithms for expedited designoptimization and explicit size reduction of compact ultra-wideband (UWB) antennas.Design/methodology/approach–Formulation of the compact antenna design problem aiming atexplicit size reduction while maintaining acceptable electrical performance is presented. Algorithmicframeworks are described suitable for handling various design situations...
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Correction of far-field measurements obtained in non-anechoic test site
Open Research DataThe dataset contains raw and processed measurements of radiation pattern characteristics performed in non-anechoic regime for two geometrically small antenna structures: a spline-parameterized Vivaldi structure and a compact spline-based monopole. The responses have been obtained at the selected frequencies of interest as a function of mentioned structures...
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Multi-objective design of miniaturized impedance transformers by domain segmentation
PublicationFast multi-objective design optimization of compact microstrip impedance transformers is discussed. Our approach exploits approximation models constructed using sampled coarse- mesh EM simulation data in a partitioned design space and response correction techniques for design refinement. Demonstra
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Inline Waveguide Filter With Compact Frequency-Dependent Coupling Producing Two Additional Poles and Three Transmission Zeros
PublicationThis work reports a compact frequency-dependent coupling (FDC) structure introduced in a rectangular waveguide, which allows to generate two additional in-band transmission poles and three transmission zeros (TZs). This serves to increase the order/selectivity of the waveguide bandpass filter in a compact inline topology, thus without the need for any additional space/volume or cross coupling. The proposed FDC consists of a partial-height...
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Fast surrogate-assisted simulation-driven design of compact microwave hybrid couplers
PublicationThis work presents a robust methodology for expedited simulation-driven design optimization of compact microwave hybrid couplers. The technique relies on problem decomposition, and a bot-tom–up design strategy, starting from the level of basic building blocks of the coupler, and finishing with a tuning procedure that exploits a fast surrogate model of the entire structure. The latter is constructed by cascading local response surface...
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The Chow Ring of flag manifolds
Open Research DataSchubert calculus is the intersection theory of 19th century. Justifying this calculus is the content of the 15th problem of Hilbert. In the course to establish the foundation of algebraic geometry, Van der Vaerden and A. Weil attributed the problem to the determination of the chow ring of flag manifolds G/P, where G is a compact Lie group and P is...
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Equivariant Morse equation
PublicationThe paper is concerned with the Morse equation for flows in a representation of a compact Lie group. As a consequence of this equation we give a relationship between the equivariant Conley index of an isolated invariant set of the flow given by x˙ = − ∇f(x) and the gradient equivariant degree of ∇f. Some multiplicity results are also presented.
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Rapid multi-objective design optimization of miniaturized impedance transformer by Pareto front exploration
PublicationFast multi-objective optimization of compact impedance transformer is discussed. A set of alternative designs representing possible trade-offs between conflicting design criteria, i.e., electrical performance (here, wideband matching) and the structure size, is obtained through Pareto front exploration by means of surrogate-assisted methods.
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Microjet technology as a perspective intensification method for high performance heat exchangers
PublicationIn the paper two oryginal designs of compact heat exchangers with intensification effect produced by microjets are presented. The technology of microjets manufacturing is an "inhouse" patented design. The idea of such heat exchanger is shown together with the flow and thermal characteristics of the prototypes. The results of performer measurements are satisfactory and encourage for further research of the original designs.
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The Hopf type theorem for equivariant gradient local maps
PublicationWe construct a degree-type otopy invariant for equivariant gradient local maps in the case of a real finite-dimensional orthogonal representation of a compact Lie group. We prove that the invariant establishes a bijection between the set of equivariant gradient otopy classes and the direct sum of countably many copies of Z.
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Karolina Lademann mgr
PeopleCurriculum vitae
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Radiation pattern measurements of geometrically small antennas performed in non-anechoic environments
Open Research DataThe dataset contains unprocessed measurements of radiation pattern characteristics performed in non-anechoic regime for three geometrically small antenna structures: a spline-parameterized Vivaldi structure, a compact spline-based monopole, and a quasi-Yagi geometry with enhanced bandwidth. The responses have been obtained over broad frequency ranges...
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Measurements of electrically small antenna radiation patterns in non-anechoic environments using TGM
Open Research DataThe dataset contains raw and processed measurements of radiation pattern characteristics performed in non-anechoic regime for four antenna structures: a spline-parameterized Vivaldi structure, a compact spline-based monopole, super-ultrawideband antenna, and a quasi-Yagi component. The responses have been obtained at the selected frequencies of interest...
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Design and Performance Evaluation of the Energy Subsystem of a Hybrid Light andWave Energy Harvester
PublicationThe paper presents the design and performance of an energy subsystem (ES) dedicated to hybrid energy harvesters (HEHs): wave energy converters (WECs) combined with photovoltaic panels (PVPs). The considered ES is intended for compact HEHs powering autonomous end-node devices in distributed IoT networks. The designed ES was tested experimentally and evaluated in relation to the mobile and wireless distributed communication use case....
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Morse inequalities via Conley index theory
PublicationThe relation known as the Morse inequalities can be extended to a more general setting of flows on a locally compact metric spaces (Conley index) as well as dynamical systems on Hilbert spaces (LS-index). This paper is a discourse around this extension. Except the part concerning the LS-index the material is self-contained and has a character of a survey.
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Quadratic stochastic operators on Banach lattices
PublicationWe study the convergence of iterates of quadratic stochastic operators that are mean monotonic. They are defined on the convex set of probability measures concentrated on a weakly compact order interval S = [0, f] of a fixed Banach lattice F. We study their regularity and identify the limits of trajectories either as the “infimum” or “supremum” of the support of initial distributions.
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Size-Reduction-Oriented Design of Compact CPW-Fed UWB Monopole Antenna
PublicationA structure and design optimization of compact CPW-fed UWB monopole antenna is presented. Explicit size reduction through constrained numerical optimization of all relevant geometry parameters of the structure leads to a very small footprint of only 321 mm2. At the same time, a very wide antenna bandwidth is achieved from 3.1 GHz to 17 GHz.
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Design considerations for compact microstrip resonant cells dedicated to efficient branch-line miniaturization
PublicationA conventional compact microstrip resonant cell (CMRC)has been thoroughly investigated to enhance its slow-wave properties and subsequently ensure an efficient miniaturization of a microstrip circuit. The geometry of a classic CMRC has been improved in terms of slowwave effect in two progressive steps: (i) a single-element topology has been replaced with a double-element one and (ii) a high-impedance section has been refined by...
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Broadside Coupled Stripline with Double-Side UC-PBG Structure.
PublicationPoddano analizie symetryczną linię paskową z dwustronnie umieszczoną na płaszczyznach masy strukturą typu UC-PBG (uniplanar compact-photonic bandgap).Zaprojektowano, wykonano i pomierzono sprzęgacz wykonany w oparciu o tego typu prowadnicę. Miniaturyzacja wymiarów układu potwierdziła spodziewany efekt spowolnienia fali wywołany wprowadzeniem struktury UC-PBG.
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Compact satellite hydraulic unit
PublicationThe article describes the design and operation of a prototype hydraulic unit. It is based on an inversed kinematics, satellite pump in which the body rotates around the shaft. The pump is placed inside the electric motor. Thanks to that the compact and low mass construction was achieved. Thanks to new commutation unit with enlarged channels, lower pressure losses were obtained. The article presents the construction and results...
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Novel doubly perforated broadband microstrip branch-line couplers
PublicationTwo broadband compact doubly perforated hybrid couplers have been designed, manufactured, and measured. To improve frequency characteristics and to reduce circuit dimensions, two kinds of perforations have been introduced: the defected ground structures in the ground plane metallization and photonic bandgap cells in the strip metallization. Measurement results show essential miniaturization (~39% and ~36%) and enhancement of the...
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Broadside coupled stripline with double-side UC-PBG structure
PublicationRozważono strukturę linii paskowych sprzężonych szerokim bokiem z periodycznie zaburzoną metalizacją masy typu UC-PBG (Uniplanar Compact - Photonic BandGap). W celu oceny przydatności struktury zaprojektowano, wykonano i przebadano sprzęgacz 3dB. Potwierdzono przewidywany efekt spowolnienia fali (slow wave effect), którego konsekwencją jest możliwość znacznej redukcji wymiarów układu.
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Study of the Effectiveness of Model Order Reduction Algorithms in the Finite Element Method Analysis of Multi-port Microwave Structures
PublicationThe purpose of this paper is to investigate the effectiveness of model order reduction algorithms in finite element method analysis of multi-port microwave structures. Consideration is given to state of the art algorithms, i.e. compact reduced-basis method (CRBM), second-order Arnoldi method for passive-order reduction (SAPOR), reduced-basis methods (RBM) and subspace-splitting moment-matching MOR (SSMM-MOR)
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Fast Antenna Optimization Using Gradient Monitoring and Variable-Fidelity EM Models
PublicationAccelerated simulation-driven design optimization of antenna structures is proposed. Variable-fidelity electromagnetic (EM) analysis is used as well as the trust-region framework with limited sensitivity updates. The latter are controlled by monitoring the changes of the antenna response gradients. Our methodology is verified using three compact wideband antennas. Comprehensive benchmarking demonstrates its superiority over both...
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Improved selectivity compact band-stop filter with gosper fractal-shaped defected ground structures
PublicationA novel band-stop filter using Gosper fractal-shaped defected ground structures has been designed and manufactured. The improvement in the filter selectivity has been achieved by introducing a multiresonance fractal-shaped defect leading to a higher filter order, simultaneously maintaining its compact size. The experimental results prove the validity of proposed solution and its utility in novel miniaturized and severe requirement...
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Database of the minimal sets of Lefschetz periods for Morse-Smale diffeomorphisms of a connected sum of g real projective planes.
Open Research DataMorse–Smale diffeomorphisms, structurally stable and having relatively simple dynamics, constitute an important subclass of diffeomorphisms that were carefully studied during past decades. For a given Morse–Smale diffeomorphism one can consider “Minimal set of Lefschetz periods”, which provides the information about the set of periodic points of considered...
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Long term measurements of PM1, PM2.5, PM10 and NO2 in open-air at Gdansk (Poland) area using low-cost sensors together with the reference results
Open Research DataThe measurements results of open-air measurements made using the following low-cost sensors: particulate matter (PM) sensor SPS30 from Sensirion, NO2 electrochemical sensor SGX-7NO2 from SGX Sensortech, NO2 electrochemical sensor 7E4-NO2 from SemaTech, compact MOS air quality sensor MiCS 2714 from SGX Sensortech, BME280 (Bosch) environmental sensor...
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A Geometrically Simple Compact Wideband Circularly Polarized Antenna
PublicationA compact broadband wide-slot circular polarization (CP) antenna is proposed. An inverted L-shape parasitic strip at the open end of a microstrip line extension and a slot modification is applied to attain wideband CP. The advantage of this technique is simplicity which makes it readily re-designable for different frequency bands. To demonstrate the concept, three designs working at different frequencies are obtained. The redesign...
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Comprehensive comparison of compact UWB antenna performance by means of multi-objective optimization
PublicationAn optimization-based procedure for comprehensive performance comparison of alternative compact UWB antenna topologies is discussed. The assessment of the antenna performance is conducted with respect to the structure size and its reflection response. More specifically, the best possible tradeoffs between these two figures of merit are identified through multiobjective optimization at the level...
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Optimizing FSO networks resilient to adverse weather conditions by means of enhanced uncertainty sets
PublicationThis work deals with dimensioning of wireless mesh networks (WMN) composed of FSO (free space optics) links. Although FSO links realize broadband transmission at low cost, their drawback is sensitivity to adverse weather conditions causing transmission degradation on multiple links. Hence, designing such FSO networks requires an optimization model to find the cheapest configuration of link capacities that will be able to carry...
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Working in harmony with nature. Green office buildings in a present-day city
PublicationMetropolis - as main point of people's migration, mostly because of work, have to face sustainable development as a strategy for the near future. This article describes possible ways leading to the best office building concepts in the design process. Searching for a workspace in harmony with nature is one of the aspects of a balanced development. The challenge is to create functional, compact, environmentally friendly and healthy...
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Application of the laser diode with central wavelength 975 nm for the therapy of neurofibroma and hemangiomas
PublicationThis paper presents newly developed dermatological laser (with central wavelength 975 nm) for application in therapies requiring deep penetration of tissue, e.g. cutaneous (dermal) neurofibroma (Recklinghausen disease) and hemangiomas. This laser can work either in pulse or continues wave mode. Laser radiation is transmitted toward the application region by optical fiber with a diameter of 0.6 mm. The compact design of the laser...
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Minimal Sets of Lefschetz Periods for Morse-Smale Diffeomorphisms of a Connected Sum of g Real Projective Planes
PublicationThe dataset titled Database of the minimal sets of Lefschetz periods for Morse-Smale diffeomorphisms of a connected sum of g real projective planes contains all of the values of the topological invariant called the minimal set of Lefschetz periods, computed for Morse-Smale diffeomorphisms of a non-orientable compact surface without boundary of genus g (i.e. a connected sum of g real projective planes), where g varies from 1 to...
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Generalized Gradient Equivariant Multivalued Maps, Approximation and Degree
PublicationConsider the Euclidean space Rn with the orthogonal action of a compact Lie group G. We prove that a locally Lipschitz G-invariant mapping f from Rn to R can be uniformly approximated by G-invariant smooth mappings g in such a way that the gradient of g is a graph approximation of Clarke’s generalized gradient of f . This result enables a proper development of equivariant gradient degree theory for a class of set-valued gradient...
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A CMRC-based compact rat-race coupler with harmonic suppression
PublicationIn this paper, an eective miniaturization technique exploiting compact microstrip resonant cells has been discussed and experimentally validated on the basis of a 3-dB microstrip rat-race coupler. The application of the method proposed has resulted in 91 % circuit area reduction in comparison to a conventional rat-race coupler. Experimental results show good agreement with theoretical characteristics, as well as an additional eect,...
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Rapid Simulation-Driven Multiobjective Design Optimization of Decomposable Compact Microwave Passives
PublicationIn this paper, a methodology for fast multiobjective optimization of the miniaturized microwave passives has been presented. Our approach is applicable to circuits that can be decomposed into individual cells [e.g., compact microstrip resonant cells (CMRCs)]. The structures are individually modeled using their corresponding equivalent circuits and aligned with their accurate, EM simulated...