Definition, Characteristics and Determining Parameters of Antennas in Terms of Synthesizing the Interrogation Zone in RFID Systems

The radio frequency identification (RFID) systems are gaining in popularity in automated processes of object identification in various socioeconomic areas. However, despite the existing belief, there is no universal RFID system on the commercial market that could be used in all user applications. All components of a developed solution should be carefully selected or designed according to the specification of objects being recognized and characteristics of their environment. In order to determine parameters of propagation or inductively coupled system, especially when it is dedicated to uncommon applications, a multiaspect analysis has to be taken into consideration. Due to complexity, the problem is reduced to analytical or experimental determination of RFID system operation range and a “trial and error” method is mostly used in the industry practice. In order to cope with the barriers existing in the RFID technology, the authors give the review of latest achievements in this field. They focus on the definition, comprehensive characteristics and determination of the antenna parameters. They also pay attention to the 3D interrogation zone (IZ) that is the main parameter in which multitude technical aspects of the RFID systems are gathered simultaneously, as regards the theoretical synthesis as well as market needs

The idea of enhancing directional energy radiation by a phased antenna array in UHF RFID system

The interrogation zone IZ is the most important parameter when RFID systems are considered. Its predictability is determined by the construction and parameters of antenna built in a read/write device. The IZ should be of sufficient size and appropriate to requirements established for an application of object automated identification. The method of shaping an antenna radiation pattern provides effective yet unconventional opportunities in this area. The idea and practical solution of the phased antenna array dedicated to UHF read/write devices are presented in the paper. On the basis of tests carried out, the authors pointed out the possibility of using developed devices for the synthesis of a determined IZ in anti-collision RFID system

Numerical Model of Directional Radiation Pattern Based on Primary Antenna Parameters

The new numerical model of directional radiation pattern, in which part of energy is emitted in side and back lobs, has been presented in this paper. The model input values are determined on the base of primary parameters that can be read from the datasheet of used antennas. The special software tool NmAntPat has been elaborated to carry out the described task. The elaborated model, program and output files can be easily implemented into an analysis of radio wave propagation phenomenon in any algorithms and numerical calculations. The comparison of the graphical plots that have been obtained on the base of measurements, producers’ data specification notes and modelling results confirms the model correctness

Determination of the material relative permittivity in the UHF band by using T and modified ring resonators

The complete methodology of designing T- and modified ring resonators in the UHF band are presented in the paper. On the basis of proposed algorithms, the dedicated software tool has been elaborated in order to determine material parameters of contemporary substrates. The program is implemented in the Mathcad environment and it includes the base of information on known materials used in electronic products. Also, test sample series for selected substrate materials (IS680, FR408, I-SPEED PCB ISOLA and A6-S LTCC FERRO) and operating frequencies from 1 GHz to 3 GHz are analyzed in details. The special test stand with a vector network analyzer has been applied in experiments. The obtained data of relative permittivity measurements and model calculations are described, discussed and concluded

Uwarunkowania efektywności układów antenowych w wielokrotnych systemach bezstykowej identyfikacji obiektów ze sprzężeniem indukcyjnym : rozprawa doktorska /

Recenzenci pracy: Andrzej Karwowski, Wiesław Ludwin.Praca doktorska. Akademia Górniczo-Hutnicza im. Stanisława Staszica (Kraków), 2007.Bibliogr. s. 161-174.Problematyka efektywności układów antenowych w wielokrotnych systemach RFID ze sprzężeniem indukcyjnym, uwarunkowania funkcjonowania wielokrotnego systemu bezstykowej identyfikacji obiektów, zakres funkcjonowania indukcyjnie sprzężonych systemów, system identyfikacji wielokrotnej, ograniczenia natężenia pola magnetycznego w indukcyjnie sprzężonych systemach, transmisja energii, wartość indukcji magnetycznej w otoczeniu pętli antenowej RWD, orientacja identyfikatora w polu magnetycznym, uwarunkowania kształtu pętli, identyfikacji prowadzonej w pobliżu obiektów zakłócających transmisje danych, komunikacja w systemie identyfikacji wielokrotnej, wielodostęp do kanału radiowego, kodowanie informacji, algorytm komunikacji w procesie identyfikacji, układ zespołów antenowych, identyfikatory, sprzężenie indukcyjne w układzie zespołów antenowych, strumień indukcji magnetycznej, indukcyjność wzajemna, zjawisko samoindukcji, identyfikator, pętla antenowa identyfikatora, układ poza polem magnetycznym, układ w polu magnetycznym, elementy zespołu antenowego, zewnętrzna pojemność rezonansowa, układ stabilizacji napięcia identyfikatora, modulatora amplitudy w identyfikatorze, minimalna wartość indukcji magnetycznej, efektywność, energetyczne, komunikacyjne uwarunkowania efektywności, czytnik/programator w układzie zespołów antenowych, pętla antenowa czytnika/programatora, zewnętrzna pojemność rezonansowa, przewód doprowadzający sygnał do anteny, układ dopasowania impedancyjnego, wpływ funkcjonującego identyfikatora na układ, model, algorytm syntezy, schemat algorytmu, dobór identyfikatora do procesu automatycznej identyfikacji, wybór typu chipu, dostępnej konstrukcji, synteza, maksymalna dobroć funkcjonującego identyfikatora, próbki, podstawowe parametry elektryczne, czułość, dobroć własna, całkowita, minimalna wartość indukcji magnetycznej, dobroć obciążonej anteny, spełnienie energetycznych uwarunkowań efektywności, metoda badania efektywności funkcjonowania układu zespołów antenowych czytnik/programator-identyfikatory, warunki, kolejność obliczeń przy wyznaczaniu obszaru poprawnej pracy wielokrotnego systemu RFID, zastosowanie metody Monte Carlo do wyznaczania, badania eksperymentalne, budowa stanowiska pomiarowego, komora pomiarowa, laboratoryjne systemy, charakterystyka, pomiar składowych wektora indukcji magnetycznej, wyznaczanie obszaru, niepewność pomiarów parametrów konstrukcyjnych, pomiaru podstawowych parametrów elektrycznych, czułości, składowych pola magnetycznego, problem niepewności wyznaczania obszaru, model MES układu bezstykowej identyfikacji obiektu ferromagnetycznego, listing programu dla ANSYS, zestawy pętli, typy chipów w pasywnych identyfikatorach, charakterystyki obszaru poprawnej pracy wielokrotnego systemy RFID ze sprzężeniem indukcyjnym dla laboratoryjnego procesu automatycznej identyfikacji obiektó

Synthesis of Antennas for Active Glazing Unit with Photovoltaic Modules

The problem considered in the paper concerns the synthesis process of antennas for autonomous semi-passive RFID transponder/sensors dedicated to active glazing units. Glazing units are frequently used in modern multi-storey buildings to create amazing facades. When they are integrated with photovoltaic (PV) modules, active units are obtained. It is desirable, mainly for economic reasons and in order to ensure the high efficiency of a micro-photovoltaic power plant, that active glazing units are equipped with a system for monitoring their operating parameters. In connection with this, design problems occur that fall within the fields of sensor technology and radio communications. The main purpose of the presented study was to prepare appropriate input data for design tools used in the synthesis of antenna systems in the UHF band. Many important issues are considered including: proximity to structural elements of the building facade and PV cells, which disturbs the shape of the radiation pattern and affects the impedance parameters of the antenna system; the need to ensure easy integration of the RFID sensor and the specified object, without significant interference in the production of glazing units; appropriate shaping of the radiation pattern in order to enable reading and writing of the RFID tag from both inside and outside the building; impedance matching to the selected RFID chip in the broadest possible frequency range, etc

Interrogation zone determination in HF RFID systems with multiplexed antennas*

The operation of an anti-collision RFID system is characterized by the interrogation zone which should be estimated in any direction of 3D space for a group of electronic transponders. The interrogation zone should be as large as possible. However, the many problems in this area are due to the fact that energy can be transferred to transponders only on a limited distance. The greatest flexibility in developing RFID applications and shaping the interrogation zone can be achieved using the system with an antenna multiplexer. Therefore the problem of the interrogation zone determination in HF RFID systems with two orthogonal RWD antennas is presented in the paper. The perceived issues have been effectively dealt with and the solution has been proposed on the basis of the elaborated model. Conducted studies have been used to develop the software tool JankoRFIDmuxHF in the Mathcad environment. The research results are analysed in an example system configuration. The specialized measuring stand has been used for experimental verification of the identification efficiency. The convergence of the measurements and calculations confirms a practical usefulness of the presented concept of interrogation zone determination in anti-collision systems. It also shows the practical utility of the developed model and software tools

A Method for Measuring the Radiation Pattern of UHF RFID Transponders

The operating principles of RFID antennas should be considered differently than it is applied in the classical theory of radio communication systems. The procedure of measuring the radiation pattern of antennas that could be applied to RFID transponders operating in the UHF band is seldom discussed correctly in the scientific literature. The problem consists in the variability of the RFID chip impedance that strongly influences measurement results. The authors propose the proper methodology for determining the radiation pattern with respect to an individual transponder as well as an electronically tagged object. The advantage of the solution consists in the possibility of using components of different measuring systems that are available in typical antenna laboratories. The proposed procedure is particularly important in terms of parameter validation - the identification efficiency and costs of an RFID system implementation can be evaluated properly only on the basis of real values of considered parameters