Nizovi kružnih valovodnih antena na sfernim strukturama

Rupčić, Slavko

prikaz prve stranice dokumenta Nizovi kružnih valovodnih antena na sfernim strukturama

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doctoral thesis

Nizovi kružnih valovodnih antena na sfernim strukturama

Zagreb, Osijek: University of Zagreb, Faculty of Electrical Engineering and Computing, 2009. urn:nbn:hr:168:004328

Rupčić, Slavko

University of Zagreb
Faculty of Electrical Engineering and Computing
Department of Communication and Space Technologies
Josip Juraj Strossmayer University of Osijek
Faculty of Electrical Engineering, Computer Science and Information Technology Osijek

Cite this document

APA 6th Edition

Rupčić, S. (2009). Nizovi kružnih valovodnih antena na sfernim strukturama (Doctoral thesis). Retrieved from https://urn.nsk.hr/urn:nbn:hr:168:004328

MLA 8th Edition

Rupčić, Slavko. "Nizovi kružnih valovodnih antena na sfernim strukturama." Doctoral thesis, University of Zagreb, Faculty of Electrical Engineering and Computing; Josip Juraj Strossmayer University of Osijek, Faculty of Electrical Engineering, Computer Science and Information Technology Osijek, 2009. https://urn.nsk.hr/urn:nbn:hr:168:004328

Chicago 17th Edition

Harvard

Rupčić, S. (2009). 'Nizovi kružnih valovodnih antena na sfernim strukturama', Doctoral thesis, University of Zagreb, Faculty of Electrical Engineering and Computing; Josip Juraj Strossmayer University of Osijek, Faculty of Electrical Engineering, Computer Science and Information Technology Osijek, accessed 26 March 2023, https://urn.nsk.hr/urn:nbn:hr:168:004328

Vancouver

Rupčić S. Nizovi kružnih valovodnih antena na sfernim strukturama [Doctoral thesis]. Zagreb: University of Zagreb, Faculty of Electrical Engineering and Computing; Osijek: Josip Juraj Strossmayer University of Osijek, Faculty of Electrical Engineering, Computer Science and Information Technology Osijek; 2009 [cited 2023 March 26] Available at: https://urn.nsk.hr/urn:nbn:hr:168:004328

IEEE

S. Rupčić, "Nizovi kružnih valovodnih antena na sfernim strukturama", Doctoral thesis, University of Zagreb, Faculty of Electrical Engineering and Computing, Zagreb; Josip Juraj Strossmayer University of Osijek, Faculty of Electrical Engineering, Computer Science and Information Technology Osijek, Osijek, 2009. Available at: https://urn.nsk.hr/urn:nbn:hr:168:004328

Cite this item: https://urn.nsk.hr/urn:nbn:hr:168:004328

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Metadata

Title	Nizovi kružnih valovodnih antena na sfernim strukturama
Title (english)	Circular waveguide antenna arrays on spherical structures
Author	Slavko Rupčić
Mentor	Zvonimir Šipuš (mentor)
Committee member	Juraj Bartolić (predsjednik povjerenstva)
Committee member	Zvonimir Šipuš (član povjerenstva)
Committee member	Nikša Burum (član povjerenstva)
Committee member	Rudolf Scitovski (član povjerenstva)
Committee member	Radovan Zentner (član povjerenstva)
Granter	University of Zagreb Faculty of Electrical Engineering and Computing (Department of Communication and Space Technologies) Zagreb
Granter	Josip Juraj Strossmayer University of Osijek Faculty of Electrical Engineering, Computer Science and Information Technology Osijek Osijek
Defense date and country	2009-01-30, Croatia
Scientific / art field, discipline and subdiscipline	TECHNICAL SCIENCES Electrical Engineering
Universal decimal classification (UDC)	621.3 - Electrical engineering
Abstract	Konformni antenski nizovi, odnosno konformne antene su nizovi koji se prilagođavaju podlozi na koju su postavljene. Kao antenski elementi konformnih nizova u mikrovalnom frekvencijskom području često se koriste otvori na konformnoj strukturi. Valovodom pobuđeni otvori su poznati po velikoj širini glavne latice, simetričnom polju kod antenskog skeniranja, dobrom prilagođenju impedancije (admitancije) te karakteristici ponašanja visokopropusnog filtra (zbog granične frekvencije valovodnih modova). Veliki kut skeniranja uz dovoljno male dimenzije jedna su od važnijih karakteristika konformnih nizova s otvor antenama. U radu su teoretski analizirani i eksperimentalno izmjereni su bitni parametri antenskih nizova na sfernoj podlozi pri čemu su kao elementarne antene korišteni valovodi kružnog poprečnog presjeka. U svrhu analize razvijen je teorijski model, odnosno numerička metoda zasnovana na numeričkom rješavanju integralne jednadžbe za magnetsko (električno) polje primjenom metode momenata. Spektralnom metodom je trodimenzionalni problem transformiran u spektar jednodimenzionalnih problema, što je znatno pojednostavilo i ubrzalo rješavanje analiziranih problema. Pri izračunu parametara niza korištene su Greenove funkcije za sferne strukture u spektralnoj domeni. Na temelju razvijene metode analize izrađen je računalni program za izračun ulazne admitancije, sprege između valovoda na sferi te dijagrama zračenja (i polarizacije) valovodnih antenskih nizova na sfernoj podlozi. Da bi se pri izračunu sprege izbjegli numerički problemi, uvedene su modificirane vektor- Legendreove transformacije i normalizirani Legendreovi polinomi. Osim toga, pri izračunima su korišteni asimptotski izrazi za Besselove i Hankelove funkcije. Pri izračunu sprege uvedena je nova metoda kod koje su, korištenjem analogije sa metodom potencijala te adicionog teorema za sferne harmonike, određeni izrazi za ekvivalentne struje u spektralnoj domeni na otvoru valovoda. Ovom metodom je značajno smanjeno vrijeme za izračun koeficijenata sprege. Utjecaj zakrivljenosti podloge na parametre antene razmatran je izračunom svih bitnih parametara valovodnog antenskog niza na sferi (ulazna admitancija, koeficijenti sprege, međuadmitancija i dijagramim zračenja) i usporedbom istih za različite radijuse sferne podloge. Teorijski model je verificiran izveden korištenjem mjerenih rezultata iz dostupne literature te mjerenjem na izvedenim laboratorijskim modelima (dva planarna i dva sferoidalna modela). Na oba laboratorijska modela načinjena su mjerenja sprege i dijagrama zračenja. Ova mjerenja nisu izvedena u bezječnoj komori, što je rezultiralo na pojavom neželjenih reflektiranih valova, a time i odstupanjima i valovitosti u izmjerenim karakteristikama antene. U svim izmjerenim slučajevima postignuto je dobro poklapanje izračunatih i izmjerenih rezultata, čime je potvrđena ispravnost teorijskog modela i prema njemu izvedenog računalnog programa.
Abstract (english)	considerations other than electromagnetics. Usually, a conformal antenna is cylindrical, spherical or some other shape, with radiating elements mounted on or integrated into the smoothly curved surface. Radiation elements – elementary antennas of these arrays are usually used aperture antennas. Apertures are microwave antennas that are usually loaded with rectangular or cylindrical waveguides. The radiation pattern of a single waveguide opening is very broad. In the thesis we studied a spherical array of circular waveguides antennas with the apertures placed on the spherical surface. The analysis is based on solving the integral equation for a magnetic field by using the moment method (MoM). The solution procedure takes advantage of the spectral domain approach where a three-dimension problem is transformed into spectral of much simpler onedimension problem. The antenna structure is rigorously taken into account by using proper Green’s functions, and the array is fully analyzed by using the element-by-element approach. A theoretical model to determine solutions for a radiation pattern, mutual coupling and input admittance was developed. We have also made the program for calculating radiation pattern, mutual coupling and input admittance of spherical waveguide arrays based on the developed MoM and spectral-domain approach. In order to avoid numerical problems, when we calculate mutual coupling, a modified vector- Legendre transformation and normalized Legendre polynomials are defined and applied to the solution procedure. We have also used asymptotic equations for Bessel and Hankel functions. This thesis demonstrates a novel approach to mutual coupling within the MoM analysis of spherical arrays by expressing the equivalent current on the waveguide aperture in terms of two suitable potential-like auxiliary functions. The new approach results in significant acceleration of the analysis of spherical antenna arrays. The influence of structure radius on input impedance, mutual coupling and radiation pattern was also investigated. In the proces of verifying theoretical results we had to built two planar and two spherical experimental models. On the spherical surface, antenna elements are placed at equidistant positions on the surface of the icosahedron. The developed theoretical model and program have been verified against measurements and results from the literature. Measurement was not performed in a well-defined anechoic chamber. The results show a very good agreement between the measured and the calculated results.
Keywords
Keywords (english)
Language	croatian
URN:NBN	urn:nbn:hr:168:004328
Project	Number: 036-0361566-1570 Title: Elektromagnetski učinci i strukture u komunikacijskim sustavima Leader: Zvonimir Šipuš Jurisdiction: Croatia Funder: MZOS Funding stream: ZP
Project	Number: 165-0361630-1636 Title: Adaptivni prijenos videosignala radijskim mrežama u heterogenom okruženju Leader: Snježana Rimac-Drlje Jurisdiction: Croatia Funder: MZOS Funding stream: Nema
Project	Number: 165-0362027-1479 Title: Širokopojasni pristup i internetske usluge u ruralnim područjima Leader: Drago Žagar Jurisdiction: Croatia Funder: MZOS Funding stream: Nema
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=33283
Type of resource	Text
Extent	184 str.
File origin	Born digital
Access conditions	Closed access
Terms of use
Repository	FER Repository
Created on	2020-03-20 11:36:59