A Review of Implementing ADC in RFID Sensor

The general considerations to design a sensor interface for passive RFID tags are discussed. This way, power and timing constraints imposed by ISO/IEC 15693 and ISO/IEC 14443 standards to HF RFID tags are explored. A generic multisensor interface is proposed and a survey analysis on the most suitable analog-to-digital converters for passive RFID sensing applications is reported. The most appropriate converter type and architecture are suggested. At the end, a specific sensor interface for carbon nanotube gas sensors is proposed and a brief discussion about its implemented circuits and preliminary results is made

RF and THz Identification Using a New Generation of Chipless RFID Tags

This article presents two chipless RFID approaches where data are reading using electromagnetic waves and where the medium encoding the data is completely passive. The former approach rests on the use of RF waves (more precisely the ultra-wide band UWB). The tags developed for this application are comparable with very specific, planar, conductive, radar targets where the relation between the tag geometry and its electromagnetic signature is perfectly known and is used to encode the data. The principle of operation as well as the realization process of the RF tags presented in this paper is similar to those already reported in the literature. However, contrary to the majority of chipless RFID tags, these labels do not present an antenna function dissociated from the circuit part where the data are stored. Here, functions such as the receiver, the treatment and the emitter of the signal are closely dependent. The data storage capacity of the RF chipless tags is proportional to of the used frequency bandwidth. As radio spectrum is regulated, the number of possible encoding bits is thus strongly limited with this technology. This is the reason why we introduce a new family of tags radically different from the preceding one, where data is encoded in volume thanks to a multilayer structure operating in the THz domain. These two approaches although different are complementary and allow to increase significantly the data storage capacity of the chipless tags. Simulation and experimental results are reported in this paper for both configurations. We demonstrate a coding capacity of 3.3 bit/cm2 for RFID chipless tags and a potential 10 bits coding capacity in the THz domain

Designing UHF RFID tag antennas with Barcode shape for dual-technology identification

In this paper, a novel methodology to design Ultra High Frequency Radio-Frequency IDentification (UHF RFID) tag antennas with Barcode layout is proposed with the challenging goal of "fusing" both technologies in a single device. Specifically, after a brief recall of the well-known barcode standard, a procedure to design meandered barcode-shaped UHF RFID tags is introduced and discussed leveraging on electromagnetic evidence. The main steps of the proposed method are described by highlighting the constraints inherited by both the adopted technologies, as well as the useful opportunities to automatise the entire antenna design process after a preliminary simulation campaign through a full-wave simulator. Different RFID-Barcode tag antennas are designed, manufactured, and characterised in terms of maximum reading range and tag sensitivity. Obtained results demonstrate the validity of the proposed approach

Mesure de circuits MMIC en boîtier par autocalibrage TRL de 2 à 18 GHz, confirmation et validation d'une analyse théorique

In this article, some microwave measurement methods and error corrections are summarised. The calibration techniques, as well as some examples and verification are shown. The principle of the TRL self-calibration method is detailed and this procedure was used for characterisation of a GaAs MMIC microstrip line on. A test fixture was designed and realised. It presents a good repeatability. This test fixture enabled the precise characterisation of this monolithic line for different applied voltages. Finally, experimental results were compared with theoretical results obtained by the modified Spectral Domain Technique, taking into account the thickness and conductivity of the metallic strips. The experimental results, between 2-18 GHz, confirmed the theoretical results but demonstrated the limit of measurement by means of bonding wires which are very dispersive above 10 GHz.Quelques méthodes de mesure hyperfréquence et de correction d'erreurs sont résumées dans cet article. Des techniques de calibrage sont aussi décrites. Des exemples de calibrage et de vérification au moyen d'éléments connus sont montrés. Le principe de l'autocalibrage TRL est détaillé, il est appliqué pour la caractérisation d'une ligne microruban à contact schottky de type MMIC sur GaAs. Une monture de test, dans un boîtier en laiton, est conçue et réalisée. Elle présente une bonne reproductibilité. Elle a permis la caractérisation précise de cette ligne monolithique pour différentes tensions de polarisation continue. L'analyse théorique repose sur la Méthode Spectrale Généralisée, améliorée pour tenir compte de l'épaisseur non nulle et la conductivité finie des métallisations. Les résultats expérimentaux obtenus entre 2 et 18 GHz, confirment les résultats théoriques mais montrent la limite de mesure au moyen de fils d'accès soudés par thermocompression au-delà de 10 GHz

Antennas for RFID tags

International audienc

Characterization of the coverage uniformity of an antenna based on its far-field

International audienc

Parametric modeling of diverse antennas designed for IR and MB-OFDM UWB systems

International audienceThis paper presents and compares the parametric modeling of several types of antennas designed for IR (Impulse Radio) and MB-OFDM (Multi-Band Orthogonal Frequency Division Multiplexing) UWB systems. Parametric models, based on the singularity expansion method, are computed in order to model the transfer functions and the impulse responses of antennas. Thus, the complexity and the accuracy of time/frequency models of diverse UWB antennas are analyzed