Analysis and Exploitation of Multiple Antennas Interaction in the Near-Field

Berra, Francesco (2018) Analysis and Exploitation of Multiple Antennas Interaction in the Near-Field, [Dissertation thesis], Alma Mater Studiorum Università di Bologna. Dottorato di ricerca in Ingegneria elettronica, telecomunicazioni e tecnologie dell'informazione, 29 Ciclo. DOI 10.6092/unibo/amsdottorato/8688.
Documenti full-text disponibili:
[img]
Anteprima
Documento PDF (English) - Richiede un lettore di PDF come Xpdf o Adobe Acrobat Reader
Disponibile con Licenza: Salvo eventuali più ampie autorizzazioni dell'autore, la tesi può essere liberamente consultata e può essere effettuato il salvataggio e la stampa di una copia per fini strettamente personali di studio, di ricerca e di insegnamento, con espresso divieto di qualunque utilizzo direttamente o indirettamente commerciale. Ogni altro diritto sul materiale è riservato.
Download (3MB) | Anteprima

Abstract

This thesis is structured in two parts. The former, and main one, introduces a novel solution for portable devices to exploit their existing communication antennas for bi-directional near-field wireless re-charging, without compromising their far-field properties. To demonstrate the concept, the GSM 900/1800MHz and the 433MHz, bands are adopted for the far-field communication and for the near-field wireless recharging, respectively. Starting with a full-wave analysis of two identical printed dipoles faced at several distances, then each antenna is fed by a frequency-selective three-port network in order to simultaneously ensure data communication at the higher frequency bands and wireless re-charging at the lower frequency band. As a proof-of-concept a system prototype is built. Port insulation, RF-to-RF and RF-to-DC power efficiency measurements demonstrates that a wireless charging and communication it is possible with the proposed link arrangement and it can thus be used to exploit the charged state of an available device to recharge another one, without limiting the respective communication capabilities. The latter part focuses on a fast design method for an RFID antenna, used as a transducer, to realize an RFID bent sensor tag. The method exploits a space mapping technique, using a coarse circuit model (CM) and a fine electromagnetic model (EM). The CM represents, in a CPU-time efficient way, the antenna transducer states to fast evaluate the sensor tag efficiency. The EM model is then used to verify the sensing states and to rapidly prototype the antenna. To demonstrate the procedure, the corresponding EM-based and CM input impedances of a T-matched dipole are compared for several sensing states over a frequency band of 840-890MHz. An innovative Figure of Merit has been. Finally the sensor tag efficiency is computed to compare the CM results with respect to the EM ones and in order to validate the entire space mapping technique.

Abstract
Tipologia del documento
Tesi di dottorato
Autore
Berra, Francesco
Supervisore
Co-supervisore
Dottorato di ricerca
Ciclo
29
Coordinatore
Settore disciplinare
Settore concorsuale
Parole chiave
SWIPT, WPT, near-field, space mapping techinque, circuit model, RFID, sensor tag, bending
URN:NBN
DOI
10.6092/unibo/amsdottorato/8688
Data di discussione
11 Maggio 2018
URI

Altri metadati

Statistica sui download

Gestione del documento: Visualizza la tesi

^