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Search results for: antenna miniaturization
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On Improved-Reliability Design Optimization of High-Frequency Structures Using Local Search Algorithms
PublicationThe role of numerical optimization has been continuously growing in the design of high-frequency structures, including microwave and antenna components. At the same time, accurate evaluation of electrical characteristics necessitates full-wave electromagnetic (EM) analysis, which is CPU intensive, especially for complex systems. As rigorous optimization routines involve repetitive EM simulations, the associated cost may be significant....
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Selected properties and parameters of radio channel impulse response estimation in ISM 2.4 GHz band
PublicationThe article presents experimental research indicating that the impulse response of the communication channel, determined in practice, are not of an universal character, but only represent its approximate value for the frequency on which this measurement was made. Phases for each of the replicas of the measurement signal were determined during the analysis of the received signals in the baseband. Phase changes of individual replicas...
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Multi-objective optimization of expensive electromagnetic simulation models
PublicationVast majority of practical engineering design problems require simultaneous handling of several criteria. For the sake of simplicity and through a priori preference articulation one can turn many design tasks into single-objective problems that can be handled using conventional numerical optimization routines. However, in some situations, acquiring comprehensive knowledge about the system at hand, in particular, about possible...
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Navy sonar's modernization developed in Gdansk University of Technology
PublicationSzybki rozwój technologii elektronicznej i metod przetwarzania sygnałów powoduje szybkie starzenie moralne systemów instalowanych na okrętach. Ponieważ kadłuby, silniki i inne, drogie, mechaniczne komponenty okrętów nie starzeją się w takim tempie i wytrzymują kilkadziesiąt nawet lat eksploatacji, istnieje głęboki sens modernizacji systemów sonarowych, z ewentualnym zachowaniem istniejących anten hydroakustycznych i ich stabilizacji....
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A structure and design optimization of novel compact microscrip dual-band rat-race coupler with enhanced bandwidth
PublicationIn the letter, a topology of a novel compact wideband dual-band rat-race coupler has been presented along with its computationally efficient design optimization procedure. Reduction of the circuit size has been achieved by meandering transmission lines of the conventional circuit. At the same time, the number of independent geometry parameters has been increased so as to secure sufficient flexibility of the circuit, necessary in...
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Macromodels for Efficient Analysis of Open-Region Problems Using the Finite Element Method
PublicationThis paper presents a local model-order reduction, called macromodeling, applied to speed-up the simulations of open-region problems, analyzed by means of finite element method. This technique is illustrated by a numerical example, which deals with a dielectric resonator antenna (DRA). The obtained results show that the proposed approach is reliable and can significantly increase the standard finite element method efficiency.
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Correction of determined coordinates of railway tracks in mobile satellite measurements
PublicationThis article examines one of the basic issues related to the technique of mobile satellite measurements in railway tracks. This problem concerns the correction of the determined coordinates of the track centerline. The need to perform this operation results from the GNSS receivers positioning at a certain height above the level of the existing track axis, leading to longitudinal and lateral shifts of antennas. The key problem here...
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Recent advances in high-frequency modeling by means of domain confinement and nested kriging
PublicationDevelopment of modern high-frequency components and circuits is heavily based on full-wave electromagnetic (EM) simulation tools. Some phenomena, although important from the point of view of the system performance, e.g., EM cross-coupling effects, feed radiation in antenna arrays, substrate anisotropy, cannot be adequately accounted for using simpler means such as equivalent network representations. Consequently, the involvement...
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Recent Advances in Accelerated Multi-Objective Design of High-Frequency Structures using Knowledge-Based Constrained Modeling Approach
PublicationDesign automation, including reliable optimization of engineering systems, is of paramount importance for both academia and industry. This includes the design of high-frequency structures (antennas, microwave circuits, integrated photonic components), where the appropriate adjustment of geometry and material parameters is crucial to meet stringent performance requirements dictated by practical applications. Realistic design has...
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Applicability of arrays of microjets heat transfer correlations to design compact heat exchangers
PublicationThe article presents experimental studies on a compact heat exchanger with heat transfer intensification by means of impinging microjets. The pursuit to provide high performance of heat exchangers is a response to the demand both in economics and in the universal tendency to miniaturization of industrial equipment. This paper presents the design and tests of a prototype, microjet heat exchanger. The modular design of the heat exchanger...
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Rapid design of miniaturised branch-line couplers through concurrent cell optimisation and surrogate-assisted fine-tuning
PublicationIn this study, the authors introduce a methodology for low-cost simulation-driven design optimisation of highly miniaturised branch-line couplers (BLCs). The first stage of their design approach exploits fast concurrent optimisation of geometrically dependent, but electromagnetically isolated cells that constitute a BLC. The cross-coupling effects between the cells are taken into account in the second stage, where a surrogate-assisted...
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A Cross-Polarisation Discrimination Analysis of Off-Body Channels in Passenger Ferryboat Environments
PublicationThere is a need for investigating radio channels for Body Area Networks considering the depolarisation phenomenon and new types of environments, since these aspects are becoming very important for systems design and deployment. This paper presents an analysis of cross-polarisation discrimination for off-body channels based on a measurement campaign performed in a passenger ferryboat, i.e., where all walls, floors and ceilings are...
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Zero-Pole Electromagnetic Optimization
PublicationA fast technique for the full-wave optimization of transmission or reflection properties of general linear timeinvariant high-frequency components is proposed. The method is based on the zeros and poles of the rational function representing the scattering parameters of the device being designed and it is the generalization of the technique developed for the design by optimization of microwave filters. The performance of the proposed...
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Proposal of a System Loss Model for Body Area Network in Passenger Ferry Environment
PublicationIn the paper, proposal of an empirical off-body system loss model for Body Area Networks working in a passenger ferry environment at 2.45 GHz has been presented. The measurements were carried out for dynamic scenarios in the discotheque passenger ferry environment. The general model formula consists of three components: mean system loss, attenuation resulting from the variable antenna position on the human body, and attenuation...
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Acceleration of the DGF-FDTD method on GPU using the CUDA technology
PublicationWe present a parallel implementation of the discrete Green's function formulation of the finite-difference time-domain (DGF-FDTD) method on a graphics processing unit (GPU). The compute unified device architecture (CUDA) parallel computing platform is applied in the developed implementation. For the sake of example, arrays of Yagi-Uda antennas were simulated with the use of DGF-FDTD on GPU. The efficiency of parallel computations...
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The shallow sea experiment with usage of linear hydrophone array
PublicationPurpose of this article is to present designed and made linear hydrophone array and the results obtained during in situ trails on Gulf of Gdańsk. The measuring system allowed to localize hydrophones in the selected points and perform measurements in both the horizontal antenna positioning and vertical. Made in this way recordings allow creating accurate 3D imaging of sound intensity/propagation. During research three floating objects...
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Recent Advances in Performance-Driven Surrogate Modeling of High-Frequency Structures
PublicationDesign of high‐frequency structures, including microwave and antenna components, heavily relies on full‐wave electromagnetic (EM) simulation models. Their reliability comes at a price of a considerable computational cost. This may lead to practical issues whenever numerous EM analyses are to be executed, e.g., in the case of parametric optimization. The difficulties entailed by massive simulations may be mitigated by the use of...
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Green analytical chemistry metrics: A review
PublicationGreen analytical chemistry encourages reducing the use of toxic chemicals/reagents, using energy-efficient equipment, and generating minimal waste. The recent trends in analytical method development focus on the miniaturization of the sample preparation devices, the development of solventless or solvent-minimized extraction techniques, and the utilization of less toxic solvents. The twelve principles of GAC serve as a basic guideline...
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Interactive Application for Visualization of the Basic Phenomena in RF and Microwave Devices
PublicationAn interactive computer application visualizing the basic phenomena in RF and microwave devices is presented. Such kind of educational package can be a very helpful tool for the students as well as for the teachers (of electronics and related fields). This paper is focused on three exemplary problems only and involves: movement of electric charge, filtering of electromagnetic waves and interference phenomena in antenna arrays. The...
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Mikropaskowy promiennik prostokątny o zredukowanych wymiarach poprzecznych
PublicationW rozdziale omówiono wyniki badań nad miniaturyzacją wymiarów poprzecznych anteny mikropaskowej przeznaczonej do pracy w systemie IFF/SSR. Zastosowanie dwóch szczelin sprzęgających: prostokątnej oraz typu H pozwoliło zwiększyć pasmo pracy oraz poprawić dopasowanie anteny. Przedstawiono wyniki symulacji oraz pomiarów parametrów anteny: WFS wejściowego oraz charakterystyk promieniowania w obu płaszczyznach ortogonalnych.
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Impact of Spatial Noise Correlation on Bearing Accuracy in DIFAR Systems
PublicationDIFAR type underwater passive systems are one of the more commonly used tools for detecting submarines. At the design stage, which usually uses computer simulations, it is necessary to generate acoustic noise of the sea. It has been shown that correlating noise significantly reduces these errors compared to the assumption that noise is uncorrelated. In addition, bearing errors have been shown to be the same in systems with a commonly...
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The computational methods in the development of a novel multianalyte calibration technique for potentiometric integrated sensors systems
PublicationIn recent years, integration and miniaturization of ion-selective electrodes (ISEs) have brought many benefits resulting in the possibility of simultaneous determination of the ions concentration in small volume samples. One of the key problems related to the preparation of potentiometric integrated sensors systems (PISSs) is a calibration procedure due to the necessity to calibrate each particular sensor separately. The main aim...
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Thermostability and photophysical properties of mixed-ligand carboxylate/benzimidazole Zn(II)-coordination polymers
PublicationThe reaction between Zn(NO3)2*6H2O or Zn(CH3COO)2*2H2O and isophthalic acid (1,3-H2bdc) in the presence of benzimidazole (Hbzim) in dimethylformamide (DMF)/ethanol (EtOH)/H2O solvent mixture at room temperature yielded two structurally different coordination polymers: [Zn2(1,3-bdc)2(Hbzim)2] (1) and [Zn2(1,3-bdc)(bzim)2] (2). (1) is a 2D-layered framework with a molecule of benzimidazole coordinated to the Zn center, whereas (2)...
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Design and Experimental Validation of a Metamaterial-Based Sensor for Microwave Imaging in Breast, Lung, and Brain Cancer Detection
PublicationThis study proposes an innovative geometry of a microstrip sensor for high-resolution microwave imaging (MWI). The main intended application of the sensor is early detection of breast, lung, and brain cancer. The proposed design consists of a microstrip patch antenna fed by a coplanar waveguide with a metamaterial layer-based lens implemented on the back side, and an artificial magnetic conductor (AMC) realized on as a separate...
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Reliable data-driven modeling of high-frequency structures by means of nested kriging with enhanced design of experiments
PublicationData-driven (or approximation) surrogate models have been gaining popularity in many areas of engineering and science, including high-frequency electronics. They are attractive as a way of alleviating the difficulties pertinent to high computational cost of evaluating full-wave electromagnetic (EM) simulation models of microwave, antenna, and integrated photonic components and devices. Carrying out design tasks that involve massive...
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COMPARISON OF SYSTEM ON CHIP TECHNOLOGIES FOR SPACE APPLICATIONS
PublicationThe paper presents a review of technologies available for the implementation of digital and mixed signal systems, particularly the system on a chip (SoC) for space applications. The phenomena encountered in the space environment are briefly presented, together with the known solutions, regarding the design of complex electronic systems. The most important norms regarding single die integrated circuits designed for space are also...
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An Improvement of Global Complex Roots and Poles Finding Algorithm for Propagation and Radiation Problems
PublicationAn improvement of the recently developed global roots finding algorithm has been proposed. The modification allows to shorten the computational time by reducing the number of function calls. Moreover, both versions of the algorithms (standard and modified) have been tested for numerically defined functions obtained from spectral domain approach and field matching method. The tests have been performed for three simple microwave...
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Green aspects, developments and perspectives of liquid phase microextraction techniques
PublicationDetermination of analytes at trace levels in complex samples (e.g. biological or contaminated water or soils) are often required for the environmental assessment and monitoring as well as for scientific research in the field of environmental pollution. A limited number of analytical techniques are sensitive enough for the direct determination of trace components in samples and, because of that, a preliminary step of the analyte...
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Application of gpr method in diagnostics of reinforced concrete structures
PublicationThis paper presents an application of the ground penetration method (GPR) for diagnostics of reinforced concrete structures. In situ measurements were conducted for three civil engineering structures: the ground floor structure, the abutment of the railway viaduct and the concrete well. The dual polarized ground penetrating radar with the antenna operating at a center frequency of 2 GHz was used for GPR surveys. Three different...
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Jacobi and gauss-seidel preconditioned complex conjugate gradient method with GPU acceleration for finite element method
PublicationIn this paper two implementations of iterative solvers for solving complex symmetric and sparse systems resulting from finite element method applied to wave equation are discussed. The problem under investigation is a dielectric resonator antenna (DRA) discretized by FEM with vector elements of the second order (LT/QN). The solvers use the preconditioned conjugate gradient (pcg) method implemented on Graphics Processing Unit (GPU)...
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Wideband Off-Body Channel Characteristics with Dynamic User
PublicationThis paper presents the preliminary results of a dynamic off-body channel characterisation study, based on wideband measurements at 5.8 GHz in an indoor environment. The Channel Impulse Response (CIR) was measured for a scenario with the user approaching and departing from the off-body antenna. A CIR deconvolution procedure was performed jointly in two polarisations, and the received signal power, Cross-Polarisation Discrimination...
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Development of a compact microstrip resonant cell aimed at efficient microwave component size reduction
PublicationA comprehensive comparison of a wide collection of compact microstrip resonant cells (CMRCs) found in the extensive body of literature has been presented. The evaluation of different CMRC designs has led to the selection of the most promising CMRC geometry for the efficient miniaturisation of modern microwave components. In order to showcase the vital effectiveness of the approach, the initially selected CMRC has been notably...
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Magnetic field mapping along a NV-rich nanodiamond-doped fiber
PublicationIntegration of NV−-rich diamond with optical fibers enables guiding quantum information on the spin state of the NV− color center. Diamond-functionalized optical fiber sensors have been demonstrated with impressive sub-nanotesla magnetic field sensitivities over localized magnetic field sources, but their potential for distributed sensing remains unexplored. The volumetric incorporation of diamonds into the optical fiber core allows...
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Reduced-Cost Design Optimization of High-Frequency Structures Using Adaptive Jacobian Updates
PublicationElectromagnetic (EM) analysis is the primary tool utilized in the design of high-frequency structures. In vast majority of cases, simpler models (e.g., equivalent networks or analytical ones) are either not available or lack accuracy: they can only be used to yield initial designs that need to be further tuned. Consequently, EM-driven adjustment of geometry and/or material parameters of microwave and antenna components is a necessary...
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Vehicular Communication Environments
PublicationCommunication to and between road vehicles (cars, truck, buses, trains, etc.) are of growing interest. This is partly due to the attractive services that cooperative intelligent transport systems (C-ITSs) provides, mainly in the areas of traffic safety and traffic efficiency. An enabler for C-ITS is wireless vehicle-to-vehicle (V2V) and vehicle-to-infrastructure (V2I) communication, collectively referred to as vehicle-to-X (V2X)...
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Zastosowanie georadaru do badań muru ceglanego
PublicationPostęp technologiczny w dziedzinie diagnostyki konstrukcji badaniami nieniszczącymi NDT (z ang. nondestructive testing) pozwala na coraz dokładniejsze określenie stanu technicznego danej konstrukcji. Jedną z tego rodzaju technik jest metoda georadarowa należąca do grupy metod elektromagnetycznych. Wykorzystuje ona zjawisko odbicia fali elektromagnetycznej na granicy ośrodków o różnych właściwościach elektrycznych. Metoda znalazła...
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Diver Observations by Means of Acoustic Methods
PublicationSearching for objects, especially small ones, moving under water near its the free surface, is always not an easy task. Designing tools for the detection of such targets is a real challenge when the possibility of a terrorist attack is a real threat. This paper presents some aspects of diver detection by means of acoustics methods, both active (side scan sonar) and passive ones (linear receiving antenna). This approach is quite...
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UNDERWATER NOISE GENERATED BY A SMALL SHIP IN THE SHALLOW SEA
PublicationStudy of the sea noise has been a subject of interest for years. The first work of this scope were published at the turn of the twentieth century by Knudsen (KNUDSEN et al., 1948) and G. Wenz (WENZ, 1962). Disturbances called "shipping noise" are one of the important components of the sea noise. In this work the results of an experimental research of underwater noise produced by a small ship of a classic propulsion are...
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Recent Advances in Loop Heat Pipes with Flat Evaporator
PublicationThe focus of this review is to present the current advances in Loop Heat Pipes (LHP) with flat evaporators, which address the current challenges to the wide implementation of the technology. A recent advance in LHP is the design of flat-shaped evaporators, which is better suited to the geometry of discretely mounted electronics components (microprocessors) and therefore negate the need for an additional transfer surface (saddle)...
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Expedited Optimization of Passive Microwave Devices Using Gradient Search and Principal Directions
PublicationOver the recent years, utilization of numerical optimization techniques has become ubiquitous in the design of high-frequency systems, including microwave passive components. The primary reason is that the circuits become increasingly complex to meet ever growing performance demands concerning their electrical performance, additional functionalities, as well as miniaturization. Nonetheless, as reliable evaluation of microwave device...
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Evaluation of Green Sample Preparation Techniques for Organic Compounds
PublicationNowadays, Green Analytical Chemistry (GAC) idea is of high importance, with impact on the rapid growth in the sample preparation area with special emphasis on sample preparation simplification, miniaturization and automation. Due to the fact that GAC is of high importance today, this study is focused on the evaluation of green sample preparation techniques for organic compounds. It is well known that sample preparation is considered...
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Low-Cost Automated Design of Compact Branch-Line Couplers
PublicationBranch-line couplers (BLCs) are important components of wireless communication systems. Conventional BLCs are often characterized by large footprints which make miniaturization an important prerequisite for their application in modern devices. State-of-the-art approaches to design of compact BLCs are largely based on the use of high-permittivity substrates and multi-layer topologies. Alternative methods involve replacement of transmission-line...
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Microextraction Techniques Used in the Procedures for Determining Organomercury and Organotin Compounds in Environmental Samples
PublicationDue to human activities, the concentrations of organometallic compounds in all parts of the environment have increased in recent decades. The toxicity and some biochemical properties of mercury and tin present in the environment depend on the concentration and chemical form of these two elements. The ever-increasing demand for determining compounds at very low concentration levels in samples with complex matrices requires...
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Bandwidth-size design trade-offs for compact spline-parameterised patch couplers by means of electromagnetic-driven multi-objective optimisation
PublicationBroad bandwidth and small size are the key performance figures for contemporary microwave couplers. These requirements are conflicting, i.e. improvement of one generally leads to degradation of the other assuming fixed topology of the circuit at hand. From a designer's perspective, the knowledge about available design trade-offs is indispensable as it permits for tailoring the circuit for particular applications as well as comparing...
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An Analysis of Elliptical-Rectangular Multipatch Structure on Dielectric-Coated Confocal and Nonconfocal Elliptic Cylinders
PublicationA rigorous analysis of the resonance frequency problem of an elliptical-rectangular microstrip structure mounted on dielectric-coated elliptic conducting cylinder, with electrically small radius, is investigated in this paper. A full-wave analysis and a moment-method calculation are employed. The analysis is carried out considering the expansion of the field as a series of Mathieu functions. The complex resonance frequencies of...
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[Komentarz do artykułu] Yin, W.-Y., Wu, B., Miao, M., Doi, L.B., Li, L.-W., and Kooi, P.-S.: Experimental characterisation and modelling of on-chip capacitors and resistors on GaAs substrates.
PublicationDokonano krytycznej oceny wartości elementów schematu zastępczego rezystorów monolitycznych wykonanych na podłożu GaAs przedstawionych w pracy: Yin, W.-Y., Wu, B., Miao, M., Doi, L.B., Li, L.-W., and Kooi, P.-S.: Experimental characterisation and modelling of on-chip capacitors and resistors on GaAs substrates, IEE Proc. Microw. Antennas and Propag., 2002,149, (1), pp.50-52.
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Resonance Frequency Calculation of a Multilayer and Multipatch Spherical Microstrip Structure Using a Hybrid Technique
PublicationThis communication offers a rigorous analysis of the resonance frequency problem of a spherical microstrip structure mounted on a multilayer, dielectric-coated metallic sphere, with an electrically small radius. The structure consists of single or multiple metallic patches with arbitrary shapes. A full-wave analysis is employed with the use of proposed hybrid approach, combining the finite-difference technique with a spectral domain...
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Reduced graphene oxide/iron(II) porphyrazine hybrids on glassy carbon electrode for amperometric detection of NADH and L-cysteine
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Global Design Optimization of Microwave Circuits Using Response Feature Inverse Surrogates
PublicationModern microwave design has become heavily reliant on full-wave electromagnetic (EM) simulation tools, which are necessary for accurate evaluation of microwave components. Consequently, it is also indispensable for their development, especially the adjustment of geometry parameters, oriented towards performance improvement. However, EM-driven optimization procedures incur considerable computational expenses, which may become impractical...
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Geospatial Coverage and Signal Quality Measurements of Terrestrial DAB+ Network in Northern Poland
PublicationModern signal coverage maps are prepared based on industry-standard radio propagation models, which take into account a number of parameters, including: type of antenna, distance from the transmitter, type of terrain, etc. However, such simulations are prone to location-specific inaccuracies, and should be verified with in-situ measurements. This paper presents results of a field test of a terrestrial DAB+ (Digital Audio Broadcasting...