252 research outputs found
Pervasive electromagmetics: sensing paradigms by passive RFID technology
No full textThings equipped with electronic labels having both identification and sensing capability could naturally be turned into digital entities in the framework of the Internet of Things. Radio frequency identification (RFID) technology offers the natural background to achieve such functionalities, provided that the basic physics governing the sensing and electromagnetic interaction phenomena are fully exploited. The sensing of Things is here reviewed from an electromagnetic perspective with the purpose of showing how advanced performance may be achieved by means of low-cost batteryless devices. A possible classification of basic sensing modalities is introduced, and many ideas, at different stages of maturity, are then discussed with the help of examples ranging from the sensing of non-living Things up to the more challenging sensing of Humans
RFIDays 2008: Workshop on emerging technologies for radio-frequency identification: book of proceedings
No full textIdentification of things and processes by Radio Frequency (RFID) is quickly growing up as the emergent technology in logistics, security and bio-engineering. Different kinds of data may be wireless transmitted from the local query unit (reader) to the remote transponder (tag) that includes the antenna and the microchip transmitter.
The most innovative research is related to affordable interrogation within complex environment, to the identification of metal objects, to the efficient scavenging of environmental energy, to the development of miniaturized active system with high autonomy, to low cost sensorial tags and to the biomedical telemetry.
On May 12-13 2008 the University of Roma Tor Vergata, Italy, in close collaboration with CNIPA, the Italian Agency for Digital Government, organized the Workshop RFIDays-2008 on the Emerging Technologies for Radiofrequency Identification. By emphasizing the natural multi-disciplinary nature of RFId context, this two-days event offered a unique review of ideas, algorithms, technology and experimentations, coming from Electronics, Electromagnetics, Telecommunications, Computer science and Logistics and proposed an extraordinary interactions between Universities, research laboratories and companies, stimulating new interests and synergies.
This proceeding collects many of the most valuable contributes, here organized into two parts respectively concerning new technologies for reader and tag design, and the development and implementation of algorithms for system-level applications with attention to security issues
MULTIPLE-PORT RFID DEVICE, METHOD OF MANUFACTURING AND USING THEREOF
No full textAn RFID system including a reader which radiates a query signal and one or more passive multiple-port tags, each comprising multiple antenna ports; each tag includes at least two chips connected to the same antenna or each to a different antenna, so that the port impedance of each chip is different, in such a manner that the features of the reply signal of each chip allow to detect one or more physical-chemical or geometric parameters of the target on which the multiple-port tag is applied, said parameters affecting both the reception of the query signal and the emission of the reply signal
The art of UHF RFID antenna design: Impedance-matching and size-reduction techniques
No full textRadio-frequency identification technology, based on the reader/tag paradigm, is quickly permeating several aspects of everyday life. The electromagnetic research mainly concerns the design of tag antennas having high efficiency and small size, and suited to complex impedance matching to the embedded electronics. Starting from the available but fragmented open literature, this paper presents a homogeneous survey of relevant methodologies for the design of UHF passive tag antennas. Particular care is taken to illustrate, within a common framework, the basic concepts of the most-used design layouts. The design techniques are illustrated by means of many noncommercial examples
RFID antennas for the UHF remote monitoring of human subjects
No full textAbstract—This paper addresses the design of passive and semi-passive transponder antennas for radio frequency identification applications involving the human body as the object to be tagged or bio-monitored. A planar tag antenna geometry, that is based on a suspended patch fed via a nested slot and is able to host sensors and electronics, is here introduced. Guidelines for conjugate impedance matching are given for different kinds of microchip transmitters, within power limitations as well as space constraints. Finally, the antenna matching performance is experimentally evaluated uti-lizing a body-tissue phantom. Index Terms—Impedance matching, planar antenna, radio fre-quency identification (RFID), sensor networks, slot antenna. I
Constrained Pole-Zero Synthesis of Phase-Oriented RFID Sensor Antennas
No full textPassive sensing by means of Radiofrequency Identification
has been extensively explored for various application,
such as gas detection, temperature change and deformations.
The sensing indicator is generally based on the amplitude and phase of the backscattered field. However, a degradation of the communication performance must be usually accepted for achieving the sensing capability. This work introduces a design method suitable for phase-based RFID sensors that permits to shape the phase response while preserving the impedance matching between the antenna and the microchip. The RFID sensor is modeled as a two-ports scatterer comprising a lumped sensor at one of the ports and a RFID chip at the other port.
A pole-zero representation of the electromagnetic interaction between the reader and the RFID sensor allows to introduce a constrained design of the antenna with a full control on the sensor dynamic range and on the communication performance. The proposed method is numerically and experimentally validated by means of a pair of strongly coupled dipoles connected to a
voltage-controlled varactor emulating a dynamic sensor response
Human body sensing: A pervasive approach by implanted RFID tags
No full textStarting from the physical evidence that passive RFID systems may be used as self-sensing devices, the feasibility of human monitoring by means of implanted tags is here investigated. The key parameters to master with the purpose to enhance the sensitivity of the implanted radiosensor have been theoretically analyzed and numerically applied to a specific medical problem, i.e. the continuous monitoring of liver cancer evolution. Preliminary experimental results with simplified phantoms corroborate the analysis
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