1,645 research outputs found
A multilayer compact-size UWB-UHF antenna system for novel RFID applications
No full textHybrid UWB-UHF antennas are deemed important for combining localization with energy harvesting. This paper enhances the design of existing work and proposes a new dual-band small-size/low-profile device for simultaneous RF energy harvesting as well as communication and localization functions. This is achieved by having the localization provided in the lower European UWB band 3.1 to 4.8 GHz, while the RF energy is harvested in the UHF RFID 868 MHz band; thus dealing with less path losses with respect to higher frequency harvesting systems (e.g. ISM band), i.e. resulting in more available RF power. Electromagnetic and nonlinear circuit simulation shows that only 43×43×6 mm3 in dimensions is needed for this dual band antenna with RF to DC conversion efficiency in the range of 50-60%, which is state-of-The-Art performance for exploiting the capabilities of such antennas. Implementation of this antenna, including matching/feeding circuitry, is under development to prove real-indoors performance
Rectenna Array with RF-Uncoupled Closely-spaced Monopoles for Autonomous Localization
No full textThe crucial role of a decoupling/matching network is demonstrated for the design of a compact 868-MHz double-antenna energy harvester, driving two different rectifiers branches for the efficient powering of a wake-up radio (WUR)-enabled localization node. Two highly-coupled meandered cross-polarized monopoles, located in close proximity, are adopted for orientation-insensitive operations, thus requiring the design of a RF-decoupling and matching network before rectification. The superior performance of the two-element harvester with respect to a standard single-monopole rectenna is experimentally demonstrated in different conditions: it justifies the deployment of the presented tag for the energy autonomy of future generation RFID tags for indoor localization
Large signal rectifier characterization for simultaneous data and Power Transfer
No full textIn this work we characterize the RF-to-baseband response of a diode used for a rectifier circuit. The measurement setup enables the synchronous acquisition of vector-calibrated baseband and RF time-domain waveforms. The behavior of a Schottky diode, widely employed for RF Energy Harvesting and Wireless Power Transfer applications, is first measured, then further optimized, in order to enable the level of accuracy needed for the correct decoding of a possible modulated input RF signal. Finally, the RF to baseband response is further validated with a single-stage rectifier, in a different measurement setup
Co-Design Strategies for Energy-Efficient UWB and UHF Wireless Systems
No full textThis paper reviews the most recent methods, combining nonlinear harmonic-balance-based analysis with electromagnetic (EM) simulation, for optimizing, at the circuit level, modern radiative RF/microwave systems. In order to maximize the system efficiency, each subsystem must be designed layoutwise, accounting for the presence of the others, that is, accounting for its actual terminations, rather than the ideal ones (50 Ω). In this way, the twofold goal of minimizing size and losses of the system is obtained by reducing intersystem matching networks. Indeed, terminations are complex, frequency-dispersive, and variable with the signal level, if active operations are concerned, and are responsible for performance degradation if not properly optimized. This approach is nowadays necessary, given the ever increased spread of pervasively distributed RF microsystems adopting miniaturized antennas, such as radio frequency identification (RFID) or wireless sensor networks, that must be low-cost, low-profile, low-power, and must simultaneously perform localization, identification, and sensing. For the design of a transmitter and a receiver connected with the respective antennas, suitable figures of merit are considered, encompassing radiation and nonlinear performance. Recent representative low-profile realizations, adopting ultra-wideband (UWB) excitations are used to highlight the benefit of the proposed nonlinear/EM approach for next generation energy autonomous microsystem, such as UWB-RFID tags
Quasi-Isotropic RF Energy Harvester for Autonomous Long Distance IoT Operations
No full textA UHF energy harvesting unit, also comprising UWB communication function, is integrated in a low-profile, compact, unique device. The optimized collocation of two couples of dual linearly-polarized dipoles provides all-polarization receiving capability and a quasi-isotropic radiation, momentous features for RF energy harvesting applications. Activation distance of a commercial ultra-low power management unit is enhanced with respect to a corresponding single-rectenna case. The EM-based non-linear simulation of the entire system has shown its ability to rectify RF power incident from any direction, with activation distances always higher than 14.7 meters for any direction of arrival and up to 26 meters in the best-case condition. Im-plementation of the presented RF harvester outperforms the cor-responding single-dipole harvester realization in a real indoor scenari
Lettera di Alessandra
No full textUn ritratto critico dell'opera di Alessandra Carnaroli, autrice fra le più apprezzate delle ultime generazioni della poesia di ricerca. La sezione a lei dedicata, nel numero della rivista, contiene inoltre saggi di Cecilia Bello Minciacchi, Andrea Cortellessa, e Ivan Schiavone; e vari inediti dell'autrice. Il saggio è pubblicato con lo pseudonimo di Tommaso Ottonieri.A critical portrait of the work of Alessandra Carnaroli, author of the most appreciated in the latest generations of italian research poetry. Published under the pseudonym Tommaso Ottonieri
Selected letters of Alessandra Strozzi
No full textThe letters of Alessandra Strozzi provide a vivid and spirited portrayal of life in fifteenth-century Florence. Among the richest autobiographical materials to survive from the Italian Renaissance, the letters reveal a woman who fought stubbornly to preserve her family's property and position in adverse circumstances, and who was an acute observer of Medicean society. Her letters speak of political and social status, of the concept of honor, and of the harshness of life, including the plague and the loss of children. They are also a guide to Alessandra's inner life over a period of twenty-three years, revealing the pain and sorrow, and, more rarely, the joy and triumph, with which she responded to the events unfolding around her.This edition includes translations, in full or in part, of 35 of the 73 extant letters. The selections carry forward the story of Alessandra's life and illustrate the range of attitudes, concerns, and activities which were characteristic of their author
Challenging the author: Gavin Douglas's Eneados
No full textGavin Douglas’s Eneados, a translation into the “Scottis” tongue of Virgil’s Aeneid, completed in 1513 and first published in London in 1553, presents, as well as the translation of the additional thirteenth book by Maphaeus Vegius, original prologues and marginal notes to the text, rubrics and articulate conclusive material. The present paper analyses this complex paratext as evidence of Douglas’s almost philological attention to the original and his preoccupation with a faithful reproduction; it is also suggested that the models for his organization of the commentary might be both medieval (i.e., manuscripts such as Petrarch’s Virgilius Ambrosianus) and early modern, as in the case of editions of classical works: the most apt example being Jodocus Badius Ascensius’ edition of the Aeneid, printed in 1501. The Eneados thus stands on the threshold between manuscript and print, and might have indicated new possibilities of use of the printing medium in Scotland, and of the value of the translation of a classical text, had history not intervened with the Scottish defeat at Flodden Fields in 1513, which put a temporary stop both to the circulation of the Eneados and to the development of Scottish printing
Nicetas Nicaenus, De azymis
No full textThe RAP online repertorium offers the first comprehensive catalogue of polemical literature related to the schism between the Roman Catholic and Orthodox Churches from the 9th to the 16th century and can be described as an ideal continuation of the *Clavis Patrum*.
Each entry identifies the work (often unpublished or newly discovered in manuscript catalogs), lists its various titles (since medieval texts often lack stable titles), provides incipit and explicit (with possible variations), and examines the manuscript tradition and foliation (by reviewing catalogs or manuscripts, verifying dates, folios, etc.). It also includes relevant bibliography (critical editions and studies), identifies the author (using prosopographical studies, dictionaries, repertories, sigillography, etc.), and provides essential biographical details. Each work is classified by literary genre (e.g., treatise, dialogue), the corresponding Byzantine term, and the main polemical themes (e.g., Filioque, Azymes, Purgatory), and is assigned a unique RAP identification number.
The Repertorium Auctorum Polemicorum is identified by the International Standard Serial Number (ISSN) 3035-2096 [continuously updated publication
Polemica scripta anonyma, Dialogus inter Graecum et Cardinales quosdam de processione Spiritus Sancti
No full textThe RAP online repertorium offers the first comprehensive catalogue of polemical literature related to the schism between the Roman Catholic and Orthodox Churches from the 9th to the 16th century and can be described as an ideal continuation of the *Clavis Patrum*.
Each entry identifies the work (often unpublished or newly discovered in manuscript catalogs), lists its various titles (since medieval texts often lack stable titles), provides incipit and explicit (with possible variations), and examines the manuscript tradition and foliation (by reviewing catalogs or manuscripts, verifying dates, folios, etc.). It also includes relevant bibliography (critical editions and studies), identifies the author (using prosopographical studies, dictionaries, repertories, sigillography, etc.), and provides essential biographical details. Each work is classified by literary genre (e.g., treatise, dialogue), the corresponding Byzantine term, and the main polemical themes (e.g., Filioque, Azymes, Purgatory), and is assigned a unique RAP identification number.
The Repertorium Auctorum Polemicorum is identified by the International Standard Serial Number (ISSN) 3035-2096 [continuously updated publication
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