Textile Antennas for Body-Centric Communication Systems

doctoral thesis

• Title (croatian): Tekstilne antene za komunikacijske sustave na ljudskom tijelu
• Author: Branimir Ivšić
• Mentor: Davor Bonefačić (mentor)
• Committee member: Davor Bonefačić (član povjerenstva)
• Granter: University of Zagreb; Faculty of Electrical Engineering and Computing; (Department of Communication and Space Technologies); Zagreb
• Defense date and country: 2013-08-26, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Electrical Engineering
• Universal decimal classification (UDC): 621.3 - Electrical engineering

Abstract

The development of personal body-centric communication systems is an important part of the new generation of wireless communication systems, and one of the recent challenges of communication science and technology. An inevitable part of any such system are antennas, which are required to ensure the wireless transfer of the signal, either within or outside the body, depending on the application. This doctoral thesis deals with the design of small wearable antennas and studying their performance in the body-centric environment by focusing on the specific characteristics of such an environment compared to free space. Several antenna prototypes were realized, and their performance was tested on the body of a human volunteer, as well as on a liquid muscle-equivalent phantom. The influence of bending and moisture in the textile substrate was researched. It was found that bending in the E-plane and low moisture content have a significant influence on the antenna characteristics. The body-centric environment is modelled analytically by calculating Green’s function in the spectral domain for a circular cylinder, and modelling the propagation around the torso using creeping waves. In the next stage, conductive threads and yarns were researched and utilized to make the conductive part of the antenna. A conductive mesh embroidered into some conventional fabric was found to be a simple method enabling both the desired conductivity, and the adequate properties of clothes to be retained. The use of a metallic button was found to be suitable for feeding, both from the aesthetical and functional points of view. Based on those findings, a general strategy for the realization of wearable antennas is proposed, and a full-textile prototype PIFA antenna has been designed, and shown to operate properly.

Abstract (croatian)

Razvoj osobnih komunikacijskih sustava na ljudskom tijelu dio je nove generacije radijskih komunikacijskih sustava te je jedan od suvremenih izazova komunikacijske znanosti i tehnologije. Sastavni dio takvih sustava su antene koje moraju osigurati radijski prijenos signala izvan i unutar tijela, ovisno o primjeni. U sklopu doktorske disertacije projektirane su male antene prikladne za nošenje na odjeći dok su njihove karakteristike istražene u okruženju ljudskog tijela te uspoređene s onima u slobodnom prostoru. Više prototipova antena ispitano je na dobrovoljcu te na tekućini električnih svojstava sličnih ljudskim mišićima. Utjecaj savijanja antene te vlage u tekstilnom supstratu također je istražen te je pokazano kako savijanje u E-ravnini i male količine vlage imaju znatan utjecaj na parametre antene. Okruženje ljudskoga tijela modelirano je i analitički proračunom Greenove funkcije u spektralnoj domeni i modeliranjem propagacije oko ljudskog torza pomoću tzv. puzajućih valova. U nastavku je istraživana upotreba vodljivih tekstilnih vlakana kojima bi se izradili vodljivi dijelovi antene. Pokazalo se kako je tekstilna mreža ušivena u neku postojeću tkaninu jednostavan postupak kojim je moguće ostvariti ravnotežu između željene vodljivosti i dobrih svojstava same odjeće. Nadalje, pokazano je kako je uporaba metalnog gumba za napajanje antene dobar kompromis s estetskog i funkcionalnog gledišta. Na temelju istraživanja prikazane su opće smjernice za izradu tekstilnih antena te je u skladu s njima izrađen i karakteriziran prototip potpune tekstilne antene tipa PIFA. Pokazalo se kako je izrađena antena funkcionalna.

• Keywords: body-centric communications; wearable textile antennas; conductive textiles; creeping waves; on-body propagation; off-body propagation; human body phantoms; PIFA antenna; influence of antenna bending; influence of moisture in textile substrate
• Keywords (croatian): komunikacije u prisutnosti ljudskog tijela; tekstilne antene; vodljivi tekstili; puzajući valovi; propagacija duž ljudskog tijela; propagacija izvan ljudskog tijela; modeli ljudskog tijela; PIFA antena; utjecaj savijanja na antenu; utjecaj vlage u tekstilnom supstratu
• Language: english
• URN:NBN: urn:nbn:hr:168:043174
• Project: Number: 036-0361566-1573; Title: Višefunkcijske antene u komunikacijskim i radarskim sustavima; Leader: Juraj Bartolić; Jurisdiction: Croatia; Funder: MZOS; Funding stream: ZP
• Study programme: Title: Doctoral study programme "Electrical Engineering and Computing"; Study programme type: university; Study level: postgraduate; Academic / professional title: doktor/doktorica znanosti, po-dručje tehničkih znanosti (doktor/doktorica znanosti, po-dručje tehničkih znanosti)
• Catalog URL: http://lib.fer.hr/cgi-bin/koha/opac-detail.pl?biblionumber=41349
• Type of resource: Text
• Extent: 241 str. ; 30 cm
• File origin: Born digital
• Access conditions: Closed access
• Created on: 2020-01-16 09:14:39