The issue of data exchange in the UHF band RFID system with an semi-passive transponder

The article discusses the specifics of data exchange in the UHF band RFID systems using semi-passive transponders. In addition to the antenna and the RFID chip, there is also an additional source of energy (eg. battery) in the structure of such transponder. The battery may be used to implement additional functions such as the ability to measure physical quantities (eg. temperature, humidity). In this regard, particular attention was paid to the discussion of phases of communication between transponder and RWD associated with additional data (measurement results). An analysis of transmitted data frames has been presented. The preliminary results of the measurements have shown that the number of memory block transmitted from transponder has an impact on the effectiveness of 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

Using the phased array antenna to increase geometric size of the interrogation zone in a UHF RFID system

An attempt to increase the geometric size of the interrogation zone in UHF RFID systems with a phased array antenna is presented in this paper. The interrogation zone should be as large as possible. However, energy can be transferred to transponders only to a limited distance. The greatest flexibility in developing RFID applications and shaping the interrogation zone can be achieved using a phased array antenna. The perceived issues have been effectively dealt with and the solution has been proposed on the basis of an elaborated model. Conducted studies have been used to develop a software tool in the Mathcad environment. The research results are analyzed in detail for different system configurations and can be implemented in practical projects to be developed in cooperation with the industry

RFID Sensors for Monitoring Glazing Units Integrating Photovoltaic Modules

The paper focuses on the synthesis of semi-passive RFID transponders-sensors that are intended to integrate with active glazing units with built-in photovoltaic cells. The main purpose of the designed construction of the UHF RFID device is to provide diagnostic information in the monitoring system of a photovoltaic micro-power plant. Furthermore, the RFID sensor is aimed at being implemented at various stages of the product life cycle: production, distribution, storage, installation, common operation, service/maintenance and disposal. In the presented research work, particular attention is paid to several aspects of the RFID sensor synthesis: use of the energy, generated periodically in the PV cells, to power the monitoring device that has to act permanently; specification of the PV module parameters that have to be monitored in the diagnostic process; implementation of data acquisition and energy management models in an electrical circuit; wireless data transfer to the master unit (monitoring host), even in the absence of power supply (e.g., module damage, blackout), using a standardized communication protocol IEC 18000-63 used in the RFID technology; and the design of the antenna system taking into consideration limitations of electronic technology and the material properties of substrates and glasses used in PV modules and RFID sensors. Based on the results of the investigations, the modular structure of the RFID sensor demonstrator is proposed. Moreover, several diagnostic scenarios are analyzed in detail. On the basis of the provided considerations, it is shown that in order to find a malfunctioning component, it is enough to compare the voltages on the photovoltaic modules that are in the close vicinity