Krzysztof Nyka - Publikacje - MOST Wiedzy

Wyszukiwarka

Filtry

wszystkich: 71

  • Kategoria
  • Rok
  • Opcje

wyczyść Filtry wybranego katalogu niedostępne

Katalog Publikacji

Rok 2002
Rok 2004
  • adaptive finite-element multigrid method in 3d magnetostatic analysis.
    Publikacja

    - Rok 2004

    Przedstawiono procedurę analizy magnetostatycznej obwodów mikrofalowych zawierających przewodniki o dowolnym kształcie. Zakłada się pobudzenie pola magnetostatycznego zadane w postaci wartości całkowitego prądu płynącego w przewodniku sygnałowym. Warunki brzegowe w strukturze od dowolnym kształcie, bez płaszczyzn symetrii wprowadza się za pomocą powierzchni rozdzielających. Takie sformułowanie problemu prowadzi jednak do szeregu...

  • Advances in computational electrodynamics.

    Artykuł prezentuje wybrane metody, które są rozwijane w Politechnice Gdańskiej, i które mogą być wykorzystane do przyspieszenia komputerowego projektowania układów mikrofalowych i analizy numerycznej układów niskiej i dużej częstotliwości. Przeprowadzono przegląd metod tworzenia układów zastępczych i ich wykorzystanie do automatycznego projektowania filtrów pasmowo-przepustowych. Przedstawiono różne podejścia reprezentacji pola...

Rok 2006
  • Receiver block of antenna amplifier for WLAN systems in 5 GHz band
    Publikacja

    - Rok 2006

    Dwukierunkowe wzmacniacze antenowe (BDA) są często stosowane do zwiększania zasięgu łączności w sieciach bezprzewodowych WLAN. W artykule przedstawiono teorię, procedurę projektową oraz realizację części odbiorczej dwukierunkowego wzmacniacza do systemów WLAN na pasma 5GHz w standardach 802.11a i HiperLAN-2. Analizowano tylko te bloki, które wpływają na parametry toru odbiorczego. Aby ograniczyć koszt wzmacniacza wszystkie obwody...

Rok 2008
  • Localization in wireless sensor networks based on zigbee platform
    Publikacja

    W artykule porównano dwie różne metody lokalizacji w sieciach sensorów bezprzewodowych. Jedną z metod jest implementacja sprzętowa algorytmu w układzie nadawczo odbiorczym CC2431. Drugą metodą jest implementacja programowa. Wyniki testów przeprowadzonych na otwartym terenie oraz w pomieszczeniach zamkniętych zostały przedstawione i porównane w pracy.

  • Low-cost handheld multiprobe reflectometer for the ism band
    Publikacja

    - Rok 2008

    W artykule przedstawiona została procedura oraz działający model taniego miernika współczynnika odbicia na pasmo ISM. Koncepcja modelu oparta jest o reflektometr z multi próbkowaniem oraz wykorzystanie zintegrowanego detektora mocy firmy Analog Devices. Prototypowy miernik z interfejsem został zbudowany. Wyniki symulacji oraz eksperymentu zostały przedstawione.

  • Methods of improving accuracy of indoor localization systems based on 802.11 standard infrastructure
    Publikacja

    - Rok 2008

    Artykuł dotyczy różnorodnych metod zwiększania dokładności istniejących już algorytmów lokalizacji, implementowanych w standardzie WLAN 802.11. W pracy przedstawiono nowatorskie rozwiązanie wykorzystujące elementy poprawiające dokładność, takie jak: algorytmy, adaptacja środowiska, filtrowanie sygnałów.

  • Modular wireless sensor network platform for RF transceiver evaluation
    Publikacja

    Artykuł przedstawia modułową technikę projektowania sieci sensorów bezprzewodowych. Uniwersalne połączenia występujące pomiędzy modułami pozwalają na zaprojektowanie nowej wersji sieci w przeciągu kilku dni zamiast tygodni. Na bazie wymienionej metodologii skonstruowane została platforma pozwalająca testować różnego rodzaju układy nadawczo odbiorcze pracujące na częstotliwościach RF.

Rok 2010
Rok 2011
  • A New Type of Macro-Elements for Efficient Two-Dimensional FEM Analysis

    This letter deals with a model order reduction technique applicable for driven and eigenvalue problems solved using the finite element method (FEM). It allows one to efficiently compute electromagnetic parameters of structures comprising small features that require strong local mesh refinement. The subdomains of very fine mesh are separated from the global domain as so called macro-elements that undergo model reduction. The macro-elements...

    Pełny tekst do pobrania w serwisie zewnętrznym

  • Testbed for development and verification of hybrid localization systems
    Publikacja

    - Rok 2011

    In this paper a testbed for development and verification of hybrid localization systems is presented. It allows for systematic analysis of hybrid localization methods and speed up the development of new schemes. The proposed testbed platform is composed of subsystem for sequential data collection and testing infrastructure that can be used for investigating the localization mechanisms in controllable environment.

    Pełny tekst do pobrania w serwisie zewnętrznym

Rok 2012
  • A Review of Antennas for Indoor Positioning Systems
    Publikacja

    - International Journal of Antennas and Propagation - Rok 2012

    This paper provides a review of antennas applied for indoor positioning or localization systems. The desired requirements of thoseantennas when integrated in anchor nodes (reference nodes) are discussed, according to different localization techniques and theirperformance. The described antennas will be subdivided into the following sections according to the nature of measurements:received signal strength (RSS), time of flight (ToF),...

    Pełny tekst do pobrania w portalu

  • Efficient model order reduction for FEM analysis of waveguide structures and resonators

    An efficient model order reduction method for three-dimensional Finite Element Method (FEM) analysis of waveguide structures is proposed. The method is based on the Efficient Modal Order Reduction (ENOR) algorithm for creating macro-elements in cascaded subdomains. The resulting macro-elements are represented by very compact submatrices, leading to significant reduction of the overall number of unknowns. The efficiency of the model...

    Pełny tekst do pobrania w serwisie zewnętrznym

  • Enhancing Performance of Switched Parasitic Antenna for Localization in Wireless Sensor Networks
    Publikacja

    This paper presents an Electronically Steerable Parasitic Array Radiator (ESPAR) antenna with enhanced performance of estimating the incoming signal direction. Designed antenna is dedicated for 2.4 GHz ISM applications with emphasis on Wireless Sensor Networks (WSN). The limitations of the existing design approach are illustrated, as well as perspectives and challenges of the proposed solution in relation to the localization in...

  • Low Power Baseband Processor for M2M Reconfigurable Radio Test Platform
    Publikacja

    Software Defined Radio (SDR) is becoming more andmore frequently used technique for wireless communication. Itfacilitates as fast prototyping and is a versatile method fordeveloping new communication systems. SDR can be realizedbased on high computational capacity platform, where powerconsumption is no a primary concern like i.e. DVB or BTStransmitters. Another trend are low power systems, whereavailable power in reduced and more...

  • Macro-elements and Model Order Reduction for Efficient Three-Dimensional FEM Analysis
    Publikacja

    An efficient model order reduction (MOR) methodology for three dimensional vector finite element method (FEM) is developed to accelerate simulations of the structures containing features that cause strong variations of mesh density. As the result of presented algorithm, FEM subsystems of equations corresponding to the selected refined region are converted into a very compact sets of linear equations, called macro-elements.Numerical...

  • Reduced order models in computational electromagnetics (in memory of Ruediger Vahldieck)

    This paper reviews research of Ruediger Vahldieck's group and the group at the Gdansk University of Technology in the area of model order reduction techniques for accelerating full-wave simulations. The applications of reduced order models to filter design as well as of local and nested(multilevel) macromodels for solving 3D wave equations and wave-guiding problems using finite difference and finite element methods are discussed.

    Pełny tekst do pobrania w serwisie zewnętrznym

  • Reliable testbed for indoor positioning systems
    Publikacja

    This paper proposes a test environment for indoor localization system, based on radio wave propagation prosperities. The following sections presents variety of problems from the assessment of the existing localization system to the analysis of inconveniences which occur when comparison of different localization systems is implemented. The problem is associated with different testing environments presented in published papers is...

Rok 2013
Rok 2014
  • A 3D-FEM mesh technique for fast analysis of waveguide problems containing rotatable tuning elements
    Publikacja

    In this paper a meshing technique for 3D Finite Element Method is presented. It allows for fast analysis and optimization of the waveguide structures, which contain rotatable tuning elements. In the proposed procedure a thin layer of varying cylindrical mesh buffer is introduced in order to reuse unchanged mesh and FEM matrices in the rest of the domain.

    Pełny tekst do pobrania w serwisie zewnętrznym

  • Dual polarization antennas for UHF RFID readers
    Publikacja

    This paper presents various concepts of switching polarization in patch antenna dedicated for UHF RFID readers. Proposed designs allow for switching between linear and circular polarization. The first design does not require electronic switching as the polarization can be changed by choosing one of two available feeding terminals. Two remaining designs use PIN diode or FET SPDT switch.

    Pełny tekst do pobrania w serwisie zewnętrznym

  • Enhanced switched parasitic antenna with switched active monopoles for indoor positioning systems
    Publikacja

    This paper presents the concept of enhanced reduced-size steerable antenna array with two rows of switched active and passive elements. Designed array is similar to ESPAR antenna but it has a set of switched monopoles instead of central one. It is intended for 2.4 GHz ISM applications with emphasis on indoor positioning systems (IPS). Proposed antenna provides improved radiation parameters and reduced dimensions in comparison to...

    Pełny tekst do pobrania w serwisie zewnętrznym

Rok 2016
  • Efficient analysis of structures with rotatable elements using model order reduction
    Publikacja

    This paper presents a novel full-wave technique which allows for a fast 3D finite element analysis of waveguide structures containing rotatable tuning elements of arbitrary shapes. Rotation of these elements changes the resonant frequencies of the structure, which can be used in the tuning process to obtain the S-characteristics desired for the device. For fast commutations of the response as the tuning elements are rotated, the...

    Pełny tekst do pobrania w portalu

  • Measurement of distance, velocity and angle of arrival using FMCW-CW combined waveform

    A procedure of tacking small flying object based on a general principle of FMCW and Doppler radar is presented. In order to increase measurement range, this technique uses active signal source on the moving object. For simultaneous measurements of distance, radial velocity and direction (AoA) as well as simplified synchronization a combined FMCW-CW waveform is proposed. The presented measurement system was realized and verified...

    Pełny tekst do pobrania w serwisie zewnętrznym

  • UHF ESPAR antenna for simple Angle of Arrival estimation in UHF RFID applications

    An electronically switched beam antenna for localization of passive UHF RFID tags based on a simple Angle of Arrival (AoA) technique is proposed‥ Detailed antenna design and realization are presented together with corresponding simulations and measurement results. Experimental tests with passive UHF RFID tag show the validity of theoretical assumptions for application of the antenna in UHF RFID based localization systems.

    Pełny tekst do pobrania w serwisie zewnętrznym

  • Wideband Model Order Reduction for Macromodels in Finite Element Method
    Publikacja

    - Rok 2016

    Abstract: This paper presents a novel algorithm for accelerating 3D Finite Element Method simulations by introducing macromodels created in local model order reduction in the selected subdomains of the computational domain. It generates the projection basis for a compact system of equations associated with a separate subdomain. Due to non-linear frequency dependency in the Right Hand Side (RHS), the standard reduction methods do...

    Pełny tekst do pobrania w serwisie zewnętrznym

  • Wireless multimodal localization sensor for industrial applications

    This paper presents the concept and design of a wireless multimodal localization sensor for hybrid localization systems combining vision-based, radio-based and inertial techniques in order to alleviate problems in harsh and complex industrial environments. It supports two radio technologies, 868 MHz UHF RFID and 2.4 GHz WSN, for positioning purposes and communications. The sensor includes LED light transmitters for vision-based...

    Pełny tekst do pobrania w serwisie zewnętrznym

Rok 2017
  • An algorithm for enhancing macromodeling in finite element analysis of waveguide components
    Publikacja

    - Rok 2017

    An algorithm for enhancing the finite element method with local model order reduction is presented. The proposed technique can be used in fast frequency domain simulation of waveguide components and resonators. The local reduction process applied to cylindrical subregions is preceded by compression of the number of variables on its boundary. As a result,the finite element large system is converted into a very compact set of linear...

    Pełny tekst do pobrania w portalu

  • Improved jamming resistance using electronically steerable parasitic antenna radiator
    Publikacja

    This paper presents an idea of using an Electronically Steerable Parasitic Antenna Radiator (ESPAR) for jamming suppression in IEEE 802.11b networks. Jamming (intentional interference) attacks are known to be effective and easy to perform, which may impose connectivity problems in applications concerning Internet of Things (IoT). In our paper, theoretical considerations are presented and the results of experiments performed in...

    Pełny tekst do pobrania w portalu

Rok 2018
  • A novel calibration method for RSS-based DoA estimation using ESPAR antennas
    Publikacja

    In this paper, we introduce a new calibration method that can successfully be used in direction of arrival (DoA) estimation using electronically steerable parasitic array radiator (ESPAR) antennas and employing power-pattern cross-correlation (PPCC) algorithm, which relies on received signal strength (RSS) values recorded at the antenna output port. Instead of the commonly used two-step approach, during which ESPAR antenna calibration...

    Pełny tekst do pobrania w serwisie zewnętrznym

  • Investigation of continuous wave jamming in an IEEE 802.15.4 network
    Publikacja

    This paper presents how continuous wave jamming affects IEEE 802.15.4 network. To this end, an office-based measurement setup has been proposed. Within the measurement area, 25 nodes have been set up in order to create a IEEE 802.15.4 tree-based test network structure. A dedicated jamming device that generates and transmits a continuous wave signal has been developed. Several tests have been conducted and presented to demonstrate...

    Pełny tekst do pobrania w serwisie zewnętrznym

  • Investigation of Continuous Wave Jamming in an IEEE 802.15.4 Network
    Publikacja

    This paper presents how continuous wave jamming affects IEEE 802.15.4 network. To this end, an office-based measurement setup has been proposed. Within the measurement area, 25 nodes have been set up in order to create a IEEE 802.15.4 tree-based test network structure. A dedicated jamming device that generates and transmits a continuous wave signal has been developed. Several tests have been conducted and presented to demonstrate...

    Pełny tekst do pobrania w portalu

  • RSS-Based DoA Estimation Using ESPAR Antenna Radiation Patterns Spline Interpolation
    Publikacja

    In this paper, it is shown how power pattern crosscorrelation (PPCC) algorithm, which relies on received signal strength (RSS) values recorded at electronically steerable parasitic array radiator (ESPAR) antenna output port, used for direction-of-arrival (DoA) estimation, can easily be improved by applying spline interpolation to radiation patterns recorded in the calibration phase of the DoA estimation process. The proposed method...

    Pełny tekst do pobrania w serwisie zewnętrznym

Rok 2019
Rok 2020

wyświetlono 3388 razy