Electrical model simulation for a UHF RFID system in near and far fields

Radio Frequency IDentification (RFID) deployment is needed for efficient item identification. A simulation environment in HP-ADS (Advanced Design System of Agilent Technologies) of Ultra High Frequency RFID systems is constructed in this paper. This paper simulates the system through an electrical model. The tag is represented by a simple empirical model representing the antenna and the chip. The chip is modeled by its impedance which varies with the code. The tag’s model is suitable for near and far field applications. A wireless channel with path loss and variable distance factors establishes the reader-tag link. The reader has a mono-static architecture. Performance of the whole system can be evaluated by changing the operating distance. Modeling improvement can be obtained by modifying the parameters of the building blocks. Finally, some simulation results are also included in this paper where data recovery is achieved.Peer ReviewedPostprint (published version

Detecting range and coupling coefficient tradeoff with a multiple loops reader antenna for small size RFID LF tags

International audienceThis paper summarizes some tests with Low Frequency (LF, 125 kHz) RFID tags of two types: Card and Token. These tests were done in order to evaluate the feasibility of an identification/traceability of tags which size is constrained and supposed to be detected inside a delimited volume of 40×40×10 cm 3 . As the size of the antenna tag is supposed to be very small, we improve the detection range and volume of definition by designing different reader antennas. Reader antennas presented are of two types whether they are based on single (SL) or multiple loops (ML). Detection range was evaluated for planar antennas (3 SL and one ML). Volume of definition for the detection was estimated by designing two-level prototypes of ML antennas. Results are discussed about the optimization possibility of detection range and volume thanks to ML

La Boucle Locale Radio et la Démodulation directe de signaux larges bandes à 26GHz.

The Wireless Local Loop (WLL) is a system using radio signals as a substitute for copper, to complete the "last mile" between the subscriber and the Public Switched Telephone Network (PSTN). The WLL must offer the following services: the phone voice, data in and digital services. In France, the frequency bands allocated to the WLL are around 26 and 3.5 GHz. The 26 GHz WLL characteristics are defined by the standard IEEE 802.16c. Within the framework of this thesis, a loop made up of two transceivers functioning in the 26 GHz band was studied. The system was initially made up of components commercially available. It was simulated with ADS software of Agilent Technologies, and then implemented at the RFM laboratory. The receivers employed in this platform were heterodyne receivers. Their structure was thus complex and the transmission deteriorated by the amplitude and phase I and Q imbalance. In order to reduce its complexity while keeping the same performances of the system, we chose to propose a new homodyne receiver by introducing the "five-port" reflectometer. The five-port reflectometer is a linear passive circuit having two inputs and three outputs. It consists of an interferometric circuit with five accesses and three power detectors. A five-port demodulator in coaxial technology was thus introduced into the 26 GHz transmission system. The demodulation being validated with this circuit, a five-port demodulator in MHIC technology was carried out. In order to regenerate the I and Q signals from the output voltages of the five-port demodulator, a particular digital algorithm processes these three signals. This digital signal processing carries out frame and symbol synchronisation simultaneously as well as carrier synchronization on each data frame. It also includes an adaptive self-calibration procedure which makes it possible to regenerate I and Q signals while compensating all the transmission chain defaults. The same digital signal processing performs also compensation of the I and Q imbalance for a classical squared demodulator. The complete transmission system was validated by carrying out the demodulation of signals modulated in QPSK and 16QAM with bit rates reaching 40 Mbit/s. The obtained phase constellation diagrams were well normalised and the bit error rates were very close of those defined by the WLL standard.La Boucle Locale Radio (BLR) ou Wireless Local Loop (WLL) est un système qui connecte les abonnés du réseau téléphonique commuté public (PSTN) grâce à une liaison radio. La BLR doit offrir les services suivants: la voix téléphonique, les données dans la bande du son et les services numériques. En France, les bandes de fréquence allouées à la BLR sont autour de 26 et 3,5 GHz. Les caractéristiques de la BLR à 26 GHz sont définies par la norme IEEE 802.16c. Dans le cadre de cette thèse, une boucle constituée de deux émetteurs/récepteurs fonctionnant dans la bande de 26 GHz a été étudiée. Le système était constitué dans un premier temps de composants disponibles commercialement. Il a été simulé avec le logiciel ADS de Agilent Technologies, et ensuite mis en œuvre au laboratoire RFM. Les récepteurs employés dans cette plate-forme étaient des récepteurs hétérodynes. Leur structure était donc complexe et la transmission altérée par les non-appariements en gain et en phase entre les voies I et Q des démodulateurs en quadrature. Afin de réduire sa complexité tout en gardant les mêmes performances du système, nous avons choisi de proposer une architecture homodyne du récepteur en introduisant le réflectomètre "cinq-port". Le réflectomètre cinq-port est un circuit passif linéaire ayant deux entrées et trois sorties. Il est constitué d'un circuit interféromètrique à cinq accès et de trois détecteurs de puissance. Un démodulateur cinq-port en technologie coaxiale a donc été introduit dans le système de transmission à 26 GHz. La démodulation étant validée avec ce circuit, un démodulateur cinq-port en technologie MHIC était réalisé. Afin de régénérer les signaux I et Q à partir des tensions de sortie du démodulateur cinq-port, un algorithme numérique particulier traite ces trois signaux. Ce traitement effectue simultanément la synchronisation trame et symbole ainsi que la synchronisation porteuse sur chaque trame de donnée transmise. Il inclut aussi une procédure adaptative d'auto-calibrage qui permet de régénérer les signaux I et Q tout en corrigeant tous les défauts de la chaîne de transmission contenant le cinq-port. Ce même traitement permet de corriger les non-appariements entre les deux voies d'un démodulateur classique en quadrature. Le système de transmission complet a été validé en réalisant la démodulation de signaux modulés en QPSK et en 16QAM avec des débits binaires atteignant 40 Mbit/s. Les diagrammes de constellation de phase obtenus étaient bien normalisés et les taux d'erreurs binaires étaient très proches que ceux définis par la norme de la BLR

La boucle locale radio et la démodulation directe de signaux larges bandes à 26 GHz

La Boucle Locale Radio (BLR) est un système qui connecte les abonnés du réseau téléphonique commuté public avec une liaison radio. En France, les bandes de fréquence allouées à la BLR sont autour de 3,5 et 26 GHz. Une boucle constituée de deux liaisons à 26 GHz a été simulée avec le logiciel ADS et ensuite mise en œuvre au laboratoire RFM à l'ENST. Les récepteurs employés dans ce système utilisaient une architecture superhétérodyne. Afin de réduire la complexité de ces récepteurs, tout en gardant les mêmes performances du système, une architecture homodyne a été proposée en introduisant le réflectomètre cinq-port. Le démodulateur cinq-port est un composant constitué d'un circuit interférométrique à deux entrées RF suivi par trois détecteurs de puissance délivrant trois tensions de sortie. Un circuit permettant la démodulation directe de signaux larges bandes à 26 GHz a ainsi été réalisé en technologie MHIC. La régénération des signaux I&Q à partir des trois tensions de sortie du démodulateur cinq-port nécessite une procédure de calibrage. Par conséquent, une méthode adaptative d'auto-calibrage, intégrant toutes les procédures de synchronisation nécessaires, a été conçue afin de corriger toutes les distorsions du système et de régénérer les signaux en bande de base. La transmission de signaux modulés en QPSK et en 16QAM avec des débits binaires atteignant 40 Mbit/s a validé le fonctionnement du système complet. Les performances obtenues en termes de taux d'erreurs binaires et de sensibilité étaient très proches de celles définies par la norme IEEE 802.16c de la BLR.The Wireless Local Loop (WLL) is a system that uses radio signals to complete the "last mile" between the subscribers and the Public Switched Telephone Network. The frequency bands allocated to the WLL in France are around 3.5 and 26 GHz. A loop constitued of two transcievers working at 26 GHz was simulated with the ADS software, and then implemented in the RFM laboratory at ENST. This platform receivers were using a superheterodyne architecture. In order to reduce the receiver complexity while keeping the same system performances, a homodyne receiver architecture was proposed by introducing the five-port reflectometer. The five-port demodulator is a component constitued of an interferometric circuit with two RF inputs followed by three power detectors delivering three output voltages. A circuit performing broadband direct demodulation at 26 GHz was then designed in MHIC technology. The regeneration of the I&Q signals from the three output voltages of the five-port demodulator requires a calibration procedure. Thus, an adaptative self-calibration method, including all needed synchronisation procedures, was defined in order to compensate all system distorsions and regenerate the baseband signals. The transmission of modulated signals by QPSK or 16QAM with bit rates reaching 40 Mbit/s validated the complete system. The obtained performance in term of bit error rate or sensitivity were very similar to those defined in the IEEE Standard 802.16c of the WLL.PARIS-Télécom ParisTech (751132302) / SudocSudocFranceF

Electrical model simulation for a UHF RFID system

Radio Frequency IDentification (RFID) deployment is needed for efficient item identification. A simulation environment in HP-ADS (Advanced Design System of Agilent Technologies) of Ultra High Frequency RFID systems is constructed in this paper. This paper simulates the system through an electrical model. The tag is represented by a simple empirical model representing the antenna by an amplifier and the chip. The chip is modeled by its impedance which varies with the code. A wireless channel with path loss and variable distance factors establishes the reader-tag link. The reader has a mono-static architecture. Performance of the whole system can be evaluated by changing the operating distance. Modeling improvement can be obtained by modifying the parameters of the building blocks. Finally, some simulation results are also included in this paper where data recovery is achieved.Peer Reviewe

Electrical model simulation for a UHF RFID system in near and far fields

Radio Frequency IDentification (RFID) deployment is needed for efficient item identification. A simulation environment in HP-ADS (Advanced Design System of Agilent Technologies) of Ultra High Frequency RFID systems is constructed in this paper. This paper simulates the system through an electrical model. The tag is represented by a simple empirical model representing the antenna and the chip. The chip is modeled by its impedance which varies with the code. The tag’s model is suitable for near and far field applications. A wireless channel with path loss and variable distance factors establishes the reader-tag link. The reader has a mono-static architecture. Performance of the whole system can be evaluated by changing the operating distance. Modeling improvement can be obtained by modifying the parameters of the building blocks. Finally, some simulation results are also included in this paper where data recovery is achieved.Peer Reviewe

Electrical model simulation for a UHF RFID system in near and far fields

Radio Frequency IDentification (RFID) deployment is needed for efficient item identification. A simulation environment in HP-ADS (Advanced Design System of Agilent Technologies) of Ultra High Frequency RFID systems is constructed in this paper. This paper simulates the system through an electrical model. The tag is represented by a simple empirical model representing the antenna and the chip. The chip is modeled by its impedance which varies with the code. The tag’s model is suitable for near and far field applications. A wireless channel with path loss and variable distance factors establishes the reader-tag link. The reader has a mono-static architecture. Performance of the whole system can be evaluated by changing the operating distance. Modeling improvement can be obtained by modifying the parameters of the building blocks. Finally, some simulation results are also included in this paper where data recovery is achieved.Peer Reviewe

Electrical model simulation for a UHF RFID system

Radio Frequency IDentification (RFID) deployment is needed for efficient item identification. A simulation environment in HP-ADS (Advanced Design System of Agilent Technologies) of Ultra High Frequency RFID systems is constructed in this paper. This paper simulates the system through an electrical model. The tag is represented by a simple empirical model representing the antenna by an amplifier and the chip. The chip is modeled by its impedance which varies with the code. A wireless channel with path loss and variable distance factors establishes the reader-tag link. The reader has a mono-static architecture. Performance of the whole system can be evaluated by changing the operating distance. Modeling improvement can be obtained by modifying the parameters of the building blocks. Finally, some simulation results are also included in this paper where data recovery is achieved.Peer Reviewe

Estimating Daily Evaporation from Poorly – Monitored Lakes using limited Meteorological Data

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