Supervisors info:
Αντώνης Αλεξανδρίδης, Διευθυντής Ερευνών, Ινστιτούτο Πληροφορικής και Τηλεπικοινωνιών, ΕΚΕΦΕ «Δημόκριτος»,
Έκτορας Νισταζάκης, Καθηγητής, Τμήμα Φυσικής, ΕΚΠΑ,
Ιωάννης Τίγκελης, Καθηγητής, Τμήμα Φυσικής, ΕΚΠΑ
Summary:
The aim of this thesis is the study and evaluation of e-textile embroidery techniques with conductive threads for the fabrication of fully textile, embroidered antennas for wireless wearable systems’ applications.
The large growth of electronics in the past decades has led to the development of a wide range of wireless devices that the user may carry around (e.g., smartphones, tablets) or wear (e.g., smart watch, smart glasses). For the needs of wireless, wearable devices, antennas that can be integrated into the clothes of the user have been developed. The research in the field of wearable antennas is extensive due to the wide variety of wearable antennas applications and research challenges.
Throughout the course of this thesis, antenna models which operated at 2.4 GHz were designed and simulated in ANSYS HFSS. Also, embroidery designs were created in PE-Design Plus 2, one of Brother’s personal embroidery design software systems for computerized embroidery machines. The embroideries were created with conductive yarns by Shieldex, using a Brother PR670E embroidery machine, which was provided by the Wireless Communications lab of the Institute of Informatics & Telecommunications at NCSR "Demokritos".
At the beginning of the thesis, different fabrication methods of textile, wearable antennas are discussed, with a focus on embroidered antennas. Afterwards, several methods of measuring the dielectric properties of fabrics are introduced. Two different dielectric measurement methods of a felt sample, which was used as a dielectric substrate for textile antennas, are described. The parameters of embroideries created with an embroidery machine, as well as details about embroidering using conductive threads are outlined in the next chapter. In the remaining of this thesis, the design and fabrication of embroidered microstrip lines on rigid substrate is described, with the aim of evaluating their effect of different embroidery parameters on their performance (transmission loss). Lastly, textile, embroidered microstrip patch antennas were designed and fabricated. The embroidered antenna models were then modified to resonate in the desired frequency. The textile antennas were measured in the anechoic chamber of the Institute of Informatics and Telecommunications, NCSR 'Demokritos'.
