Filtry
wszystkich: 839
Wyniki wyszukiwania dla: UNFOLDING CIRCUIT
-
Improved RSS-Based DoA Estimation Accuracy in Low-Profile ESPAR Antenna Using SVM Approach
PublikacjaIn this paper, we have shown how the overall performance of direction-of-arrival (DoA) estimation using lowprofile electronically steerable parasitic array radiator (ESPAR) antenna, which has been proposed for Internet of Things (IoT) applications, can significantly be improved when support vector machine (SVM) approach is applied. Because the SVM-based DoA estimation method used herein relies solely on received signal strength...
-
Multiple output CMOS current amplifier
PublikacjaIn this paper the multiple output current amplifier basic cell is proposed. The triple output current mirror and current follower circuit are described in detail. The cell consists of a split nMOS differential pair and accompanying biasing current sources. It is suitable for low voltage operation and exhibits highly linear DC response. Through cell devices scaling, not only unity, but also any current gains are achievable. As...
-
Simple Measurement Method for Resistive Sensors Based on ADCs of Microcontrollers
PublikacjaA new, complete measurement method for resistance measurement of resistive sensors for systems based on microcontrollers equipped with analog-to-digital converters (ADCs) is proposed. The interface circuit consists of only four resistors, including a resistive sensor and a reference resistor, connected directly to the microcontroller pins. It is activated only during measurements, which significantly reduces power consumption....
-
Fault-tolerant performance of the novel five-phase doubly-fed induction generator
PublikacjaThe article presents the concept of a new design of a multi-phase doubly-fed induction generator (DFIG). The innovative design approach uses a five-phase power supply from the rotor side of the generator with a three-phase classic stator power supply. Modern three-phase doubly-fed induction generators are the dominant choice for Wind Energy Conversion Systems (WECS). Solutions of this type are sensitive to the loss of at least...
-
Vehicle Detection with Self-Training for Adaptative Video Processing Embedded Platform
PublikacjaTraffic monitoring from closed-circuit television (CCTV) cameras on embedded systems is the subject of the performed experiments. Solving this problem encounters difficulties related to the hardware limitations, and possible camera placement in various positions which affects the system performance. To satisfy the hardware requirements, vehicle detection is performed using a lightweight Convolutional Neural Network (CNN), named...
-
Reducing common mode voltage and bearing currents in quasi - resonant DC - link inverter
PublikacjaIn the paper, a concept of separation of an inverter-fed induction motor drive from its mains supply by two transistor switches inserted in the dc-link circuit is reexamined based on the proposed parallel quasi-resonant dc-link inverter (PQRDCLI). The objective of the paper is to show an advantage of the proposed topology in limiting high frequency common mode voltage and bearing currents. In the laboratory setup, an induction...
-
A Simple-Topology Compact Broadband Circularly Polarized Antenna With Unidirectional Radiation Pattern
PublikacjaIn this letter, a geometrically simple, reflector-backed single-point-fed circularly polarized (CP) antenna with unidirectional radiation pattern is presented. The structure comprises a simple coplanar waveguide (CPW) feeding circuit with an open slot etched on one side of the coplanar ground. The enhanced CP bandwidth is obtained by combining the loop mode, the slot mode, and the asymmetrical configuration of the coplanar ground...
-
SIMPLY AND LOW COAST ELECTROMYOGRAPHY SIGNAL AMPLIFIER
PublikacjaRecently, there has been a noticeable increase in interest in solu tions utilizing electrical signals accompanying muscle activity. Electromyography (EMG) is a technique for recording, analysis and evaluating the electrical activity produced by striated muscle. Its great popularity is due, among other, to the ability to measure with non-invasive electrodes (calle d as sEMG surface electromyography)....
-
On the low-cost design of abbreviated multisection planar matching transformer
PublikacjaA numerically demanding wideband matching transformer composed of three nonuniform transmission lines (NUTLs) has been designed and optimized at a low computational cost. The computational feasibility of the design has been acquired through the exploitation of low-fidelity NUTL models in most steps of the design procedure and an implicit space mapping optimization engine, providing high accuracy results with only a handful of EM...
-
CM Voltage Compensators for Power Electronic Interfaces
PublikacjaThe experimental results presented in the paper have shown that the application of the PEIs might cause EMC related problems, especially in the case of the application of a group of connected converters. The most convenient way to reduce EMI currents and prevent aggregation of EMI currents introduced by a group of converters is through passive compensation of voltage interference sources inside of the single converters. In the...
-
Using an IEEE1149.1 Test Bus for Fault Diagnosis of Analog Parts of Electronic Embedded Systems
PublikacjaThe new solution of a BIST called the JTAG BIST for self-testing of analog parts of electronic embedded systems is presented in the paper. The JTAG BIST consists of the BCT8244A and SCANSTA476 integrated circuits of Texas Instruments controlled via the IEEE 1149.1 bus. The BCT8244A is a scan test device with octal buffers, and the SCANSTA476 is a 12-bit ADC with 8 analog input channels. Self-testing approach is based on the fault...
-
Two-Rate Based Low-Complexity Variable Fractional-Delay FIR Filter Structures
PublikacjaThis paper considers two-rate based structures for variable fractional-delay (VFD) finite-length impulse response (FIR) filters. They are single-rate structures but derived through a two-rate approach. The basic structure considered hitherto utilizes a regular half-band (HB) linear-phase filter and the Farrow structure with linear-phase subfilters. Especially for wide-band specifications, this structure is computationally efficient...
-
Dynamic range comparison of voltage-mode and current-mode state-space Gm-Cbiquad filters in reciprocal structures
PublikacjaW pracy dokonano porównania zakresu dynamicznego bikwadratowych filtrówGm-C zmiennych stanu, których struktury układowe oparte są na zasadzie tran-sformacji układu dołączonego. Przeprowadzono rozważania teoretyczne w wynikuktórych określono ogóne formuły zakresu dynamicznego dla klasy filtrów Gm-Ctrybu napięciowego i prądowego. Weryfikacja rezultatów teoretycznych byłazrealizowana za pomocą symulatora SPICE.
-
Single-Slope ADC With Embedded Convolution Filter for Global-Shutter CMOS Image Sensors
PublikacjaThis brief presents an analog-to-digital converter (ADC) suitable for acquisition and processing of images in the global-shutter mode at the pixel level. The ADC consists of an analog comparator, a multi-directional shift register for the comparator states, and a 16-bit reversible binary counter with programmable step size. It works in the traditional single-slope mode. The novelty is that during each step of the reference ramp,...
-
Frequency-Reconfigurable Hybrid SIW-Based Self-Diplexing Antenna Using Solid and Liquid Dielectric Loading
PublikacjaThis paper presents a novel frequencyreconfigurable self-diplexing antenna (SDA) utilizing a hybrid substrate-integrated waveguide (SIW). The antenna comprises a radiating slot, a feeding network, and a hybrid SIW cavity featuring half-mode circular and half-mode rectangular SIW structures. The unique feature of this antenna lies in its fine-tuning capability of each resonant frequency by inserting or injecting solid and liquid...
-
A complex variable fractional-delay FIR filter structure
PublikacjaW artykule wprowadzamy strukturę zespolonego filtru o skończonej odpowiedzi impulsowej (ang. finite impulse response - FIR) ze zmiennym opóźnieniem ułamkowym (ang. fractional delay - FD). Strukturę tę otrzymujemy na podstawie przestrajanego filtru FD FIR o współczynnikach rzeczywistych. Stanowi ona połączenie zbioru liniowo-fazowych filtrów FIR o współczynnikach stałych rzeczywistych i dwóch łańcuchów mnożąco-akumulujących, zawierających...
-
A fractionally delaying complex Hilbert transform filter
PublikacjaPrzedstawiono nowy, dyskretno-czasowy, ułamkowo-opóźniający (FD od ang. fractional delayor), zespolony filtr Hilberta (HTF od ang. Hilbert transform filter) nazwany FDHTF. Filtr ten jest oparty na parze obróconych filtrów o zmiennym opóźnieniu ułamkowym (VFD od ang. variable fractional delayor). Za pomocą filtru FDHTF realizuje się jednocześnie filtrację Hilberta i wprowadzanie ułamkowego opóźnienia do przetwarzanego sygnału. Dzięki...
-
A Compact Self-Hexaplexing Antenna Implemented on Substrate-Integrated Rectangular Cavity for Hexa-Band Applications
PublikacjaThis brief introduces a novel architecture of a compact self-hexaplexing antenna (SHA) implemented on a substrate-integrated rectangular cavity (SIRC) for hexa-band applications. The proposed SHA is configured by using an SIRC resonator, two Pi-shaped slots (PSSs), and six 50Ω microstrip feedlines. The PSSs are connected back-to-back and loaded on top of the SIRC resonator to produce six patch radiators (PRs). The PRs are excited...
-
A Five-Leg Three-Level Dual-Output Inverter
PublikacjaClassical 3-level dual-output inverter, 3-L DOI, involves two similar 3-level inverters that provides a pair of 3-phase output voltages with same or different frequencies from common input voltage source. Flexibility of either operation of the constituting inverters is evident in this DOI; but total duplication of power switches is a major drawback. State of the art coupled 3-L DOIs reduce this drawback by providing series-shared...
-
RF Multi-Functional Input-Reflectionless Dispersive-Delay Structure With Sharp-Rejection Filtering Using Channelization Techniques
PublikacjaA class of RF multi-functional input-reflectionless dispersive-delay structure (DDS) with linear-type in-band groupdelay variation and sharp-rejection bandpass-filtering capability is reported. It exploits a two-branch-channelized/balanced-type circuit with similar low-order reflective DDS units inside its channels, which are connected through input/output 3-dB quadrature wideband couplers. The adopted DDS unit is based on a coupledresonator...
-
Design and Optimization of Metamaterial-Based 5G Millimeter Wave Antenna for Gain Enhancement
PublikacjaIn this brief, a low profile, broadband, high-gain antenna array based on optimized metamaterials (MMs) with dual-beam radiation is reported for 5G millimeters wave (mm-wave) applications. The design is a simple bow tie operating at a 5G band of 28 GHz. It consists of two bow ties with substrate integrated waveguide (SIW)-based power splitter. A broad impedance bandwidth of 26.3−29.8 GHz is obtained by appropriately combining the...
-
A CMOS Pixel With Embedded ADC, Digital CDS and Gain Correction Capability for Massively Parallel Imaging Array
PublikacjaIn the paper, a CMOS pixel has been proposed for imaging arrays with massively parallel image acquisition and simultaneous compensation of dark signal nonuniformity (DSNU) as well as photoresponse nonuniformity (PRNU). In our solution the pixel contains all necessary functional blocks: a photosensor and an analog-to-digital converter (ADC) with built-in correlated double sampling (CDS) integrated together. It is implemented in...
-
Compact, Order Extensible and Wide-Stopband Bandpass Filter Based on SIW Cavity with Rectangular Ring Slot
PublikacjaThis article introduces novel architectures of bandpass filters (BPFs) using a substrate integrated waveguide (SIW) cavity with a rectangular ring slot (RRS) for compact size, extensible order, and broad stopband responses. Two bandpass filters, which demonstrate a second-and a fourth-order Chebyshev response, respectively, are realized by employing identical cavities with RRS, without increasing the physical size of the circuit....
-
A Power-Efficient Digital Technique for Gain and Offset Correction in Slope ADCs
PublikacjaIn this brief, a power-efficient digital technique for gain and offset correction in slope analog-to-digital converters (ADCs) has been proposed. The technique is especially useful for imaging arrays with massively parallel image acquisition where simultaneous compensation of dark signal non-uniformity (DSNU) as well as photo-response non-uniformity (PRNU) is critical. The presented approach is based on stopping the ADC clock by...
-
Low-Power Receivers for Wireless Capacitive Coupling Transmission in 3-D-Integrated Massively Parallel CMOS Imager
PublikacjaThe paper presents pixel receivers for massively parallel transmission of video signal between capacitive coupled integrated circuits (ICs). The receivers meet the key requirements for massively parallel transmission, namely low-power consumption below a single μW, small area of less than 205 μm2, high sensitivity better than 160 mV, and good immunity to crosstalk. The receivers were implemented and measured in a 3-D IC (two face-to-face...
-
Modernization of historic healthcare buildings
PublikacjaThe practice of transforming and adapting the existing healthcare facilities to meet the growing demands of modern medicine applies not only to buildings of historical value. Of course, one can set a time point from which hospitals, erected mostly with industrialized technologies, undergo upgrades for better or worse effect. Existing healthcare buildings or facilities, including historic ones, have to be refurbished and adapted...
-
Two bacterial small heat shock proteins, IbpA and IbpB, form a functional heterodimer
PublikacjaSmall heat shock proteins (sHsps) are a conserved class of ATP-independent chaperones which in stress conditions bind to unfolded protein substrates and prevent their irreversible aggregation. Substrates trapped in sHsps-containing aggregates are efficiently refolded into native structures by ATP-dependent Hsp70 and Hsp100 chaperones. Most γ-proteobacteria possess a single sHsp (IbpA), while in a subset of Enterobacterales, as...
-
Refinement of the Hardening Soil model within the small strain range
PublikacjaThe popularity of the elasto-plastic Hardening Soil (HS) model is based on simple parameter identification from standard testing and empirical formulas. The HS model is implemented in many commercial FE codes designed to analyse geotechnical problems. In its basic version, the stress–strain behaviour within the elastic range is subject to the hypoelastic power law, which assures the barotropy of the elastic stiffness. However,...
-
The Use of the Language of Mathematics as an Inspiration for Contemporary Architectural Design
PublikacjaThe purpose of the article is to present the evolution of the use of mathematical language as an inspiration for creating spatial, three-dimensional forms in art and architecture. The article focuses on the possibilities for art and architectural design ideas gained by contemporary mathematics, algorithms and computational parametric approach. The analysis of various examples represents the relationships between the composition...
-
Detection of inter-turn faults in transformer winding using the capacitor discharge method
PublikacjaThe paper presents results of an analysis of inter-turn fault effects on the voltage and current waveforms of a capacitor discharge through transformer windings. The research was conducted in the frame of the Facility of Antiproton and Ion Research project which goal is to build a new international accelerator facility that utilizes superconducting magnets. For the sake of electrical quality assurance of the superconducting magnet...
-
The contactless method of chip-to-chip high-speed data transmission monitoring
PublikacjaThis paper presents a technique of decoupling differential signals transmitted in a pair of microstrip lines on a printed circuit board (PCB), using dedicated coupler for high speed data transmission monitoring in chip-to-chip interconnections. The coupler used for signal probing is overlayed on the pair of microstrip lines under test, and provides a signal to the next blocks of the measurement system without disturbing transmission...
-
Low-cost and reliable geometry scaling of compact microstrip couplers with respect to operating frequency, power split ratio, and dielectric substrate parameters
PublikacjaA technique for rapid re-design of miniaturised microstrip couplers with respect to operating conditions as well as material parameters of the dielectric substrate is proposed. The dimension scaling process is based on a set of pre-optimised reference designs, obtained for an equivalent circuit model of the coupler at hand. The reference designs are utilised to construct an inverse surrogate model which – upon suitable correction...
-
Portable exhaled breath analyzer employing fluctuation-enhanced gas sensing method in resistive gas sensors
PublikacjaThis paper presents a portable exhaled breath analyser, developed to detect selected diseases. The set-up employs resistive gas sensors: commercial MEMS sensors and prototype gas sensors made of WO3 gas sensing layers doped with various metal ingredients. The set-up can modulate the gas sensors by applying UV light to induce physical changes of the gas sensing layers. The sensors are placed in a tiny gas chamber of a volume...
-
In-situ and ex-situ resistance measurements of polypyrrole film using double-band electrode
PublikacjaMany in-situ techniques are performed in order to determine the resistance of conducting polymer film. However, the resistance measured in solution can be the combination of polymer resistance and that of other components, such as resistance of supporting electrolyte. Therefore, in this work, the influence of the solution on the resistance of polypyrrole (PPy) film has been studied. PPy film was electrchemically synthesized onto...
-
Photovoltaic Maximum Power Point Technique based on Incremental Conductance (INCON) control algorithm
PublikacjaMaximum output power status can significantly improve the deployment rate of solar energy system. In order to get the maximum power output, issue of tracking maximum power point (MPP), reduced harmonics around MPP and improve efficiency of the solar power energy system, this paper presents the improved maximum power point tracking (MPPT) control...
-
Highly stable CsFAPbIBr perovskite solar cells with dominant bulk recombination at real operating temperatures
PublikacjaMixed-cation mixed-halide perovskite solar cells have been characterized in DC at different temperatures (from −20 °C up to 50 °C) and the time evolution of the device efficiency has been assessed using different degradation protocols (indoors and outdoors). The completely planar p–i–n structure is ITO/CuNiOx/PTAA/CsFAPbIBr/PCBM/PEI/Ag. Pristine current–voltage characteristics barely show hysteresis, at any temperature. Open circuit...
-
Design of an Autonomous IoT Node Powered by a Perovskite-Based Wave Energy Converter
PublikacjaThis paper presents the results of experimental research focused on wave energy harvesting and its conversion to power Internet of Things (IoT) devices. The harvesting and conversion process was performed using a wave energy converter (WEC) consisting of a lead zirconate titanate piezoelectric ceramic perovskite material and a prototype power electronic circuit. The designed WEC was considered as a power supply for an end node...
-
Innovative Bidirectional Isolated High-Power Density On-Board Charge for Vehicle-to-Grid
PublikacjaThis paper deals with developing and implementing a bidirectional galvanically isolated on-board charger of a high-power density. The power density of the new charger was 4 kW/kg and 2.46 kW/dm3, and the maximum efficiency was 96.4% at 3.4 kW. Due to the requirement to achieve a high-power density, a single-stage inverter topology was used. Regarding switching losses, due to the topology of the circuit with so-called hard switching,...
-
Asynchronous Charge Carrier Injection in Perovskite Light-Emitting Transistors
PublikacjaUnbalanced mobility and injection of charge carriers in metal-halide perovskite light-emitting devices pose severe limitations to the efficiency and response time of the electroluminescence. Modulation of gate bias in methylammonium lead iodide light-emitting transistors has proven effective in increasing the brightness of light emission up to MHz frequencies. In this work, a new approach is developed to improve charge carrier...
-
Diagnostics of induction motor bearings - possibility of measurements
PublikacjaIn induction motors damage in the elements of electromagnetic system, for example in the wiring of stator, rotor or in the magnetic circuit can appear as well as damage of mechanical parts (bearings, rotor, shaft). Bearing diagnostics is so important in supervision of motor condition, because extensive research shows that the bearings arethe elements most susceptible to damage. This paper presents the research which the author...
-
Design of Frequency-Reconfigurable Branch-Line Crossover Using Rectangular Dielectric Channels
PublikacjaThis paper presents an efficient yet straightforward passive reconfiguration technique to tune the operating frequency of a branch-line crossover (BLCO). The underlying principle is to fill rectangular dielectric channels (RDCs) prepared beforehand with either air or materials of different relative permittivity. Two configurations (one RDC and three RDCs in each arm) of the branch-line crossover are employed to estimate the tunability...
-
Two-Row ESPAR Antenna with Simple Elevation and Azimuth Beam Switching
PublikacjaIn this letter, we propose a two-row electronically steerable parasitic array radiator (ESPAR) antenna designed for direction of arrival (DoA) estimation in Internet of Things (IoT) applications relying on simple microcontrollers. The antenna is capable of elevation and azimuth beam switching using a simple microcontroller-oriented steering circuit and provides 18 directional radiation patterns, which can be grouped in 3 distinctive...
-
Recent advances in high-frequency modeling by means of domain confinement and nested kriging
PublikacjaDevelopment 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...
-
Układy napędowe pojazdów elektrycznych
PublikacjaW artykule omówiono nowe technologie stosowane w układach napędowych pojazdów elektrycznych. Praca zawiera zależności teorii ruchu pojazdu, nowe rozwiązania w konstrukcji silników trakcyjnych. Przedstawiono również zagadnienia układów zasilania bateryjnego i magazynów energii z superkondensatorami. Pokazano metody sterowania zapewniające optymalizacje rozdziału energii pomiędzy akumulatorami a magazynem energii. Zaprezentowano...
-
Low-frequency tripping characteristics of residual current devices
PublikacjaFast development of various types of converters makes their utilization in industry and in domestic installations very common. Due to converters, an earth fault current waveform in modern circuits can be distorted or its frequency can be different than 50/60 Hz. Frequency of earth fault (residual) current influences tripping of residual current devices which are widely used in low voltage systems. This paper presents the behaviour...
-
Koncepcja, modelowanie i symulacja układu napędowego prototypu samochodu elektrycznego "ELV001"
PublikacjaAbstract: In this paper a conception, modelling and simulation tool for drive system of the prototype electric vehicle ''ELV001'' have been presented. The design and building of this vehicle have been carried out in frame of the project: ''Building a market of electric vehicle and charging infrastructure - fundamentals of energy safety''. The simulation tools are of great assistance to engineers and researchers to reduce product-development...
-
Imaging of ferroelectric properties of sinter by means of Piezoresponse Force Microscopy
Dane BadawczeFerroelectricity is a property of certain materials [1], characterized by a spontaneous electrical polarization that can be reversed by applying an external electric field. Ferroelectric properties can be used to make capacitors with adjustable capacity. The permeability of ferroelectrics is not only regulated, but usually also very high, especially...
-
Composition of fatty acids in selected sorts of biscuits, offered for children
PublikacjaThe fatty acid (FA) composition, especially total trans-fatty acids (TFA) content in 12 assortments of biscuits offered for children, produced by four different companies, were determined by gas chromatography. Total fat content of the biscuit samples ranged from 2.2 to 22.8 g/100 g of product. The major FAs were palmitic C16:0, oleic C18:1, and linoleic C18:2 acids. Depending on the biscuit type, the total saturated fatty acids...
-
Modelling and analysis of medium frequency transformers for power converters
PublikacjaThe evolutions in power systems and electric vehicles, related to the economic opportunities and the environmental issues, bring the need of high power galvanically isolated DC-DC converter. The medium frequency transformer (MFT) is one of its key components, enabled by the increasing switching frequency of modern power semiconductors like silicon carbide transistors or diodes. The increased operating frequency offers small...
-
Fabrication and Study of BiNbO4 Ceramics
PublikacjaAim of the present research was to fabricate and study crystalline structure as well as dielectric properties of BiNbO4 ceramics. In the present study BiNbO4 ceramics was fabricated by solid state reaction from the mixture of simple oxides viz. Bi2O3, and Nb2O5. Stoichiometric mixture of the powders was thermally analyzed so parameters of the thermal treatment were determined. The EDS measurements proved conservation of the chemical...