Upotreba pasivnih i aktivnih mreža za poboljšanje svojstava malih antena

master's thesis

• Title (english): Application of passive and active networks for improving characteristics of small antennas
• Author: Katarina Krmek
• Mentor: Silvio Hrabar (mentor)
• Committee member: Silvio Hrabar (predsjednik povjerenstva)
• Committee member: Zvonimir Šipuš (član povjerenstva)
• Committee member: Marko Bosiljevac (član povjerenstva)
• Granter: University of Zagreb; Faculty of Electrical Engineering and Computing; Zagreb
• Defense date and country: 2023-07-14, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Computing
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Electrical Engineering

Abstract

U ovome diplomskome radu najprije su predstavljena osnovna svojstva antena potrebna za razumijevanje zadatka. Zatim su uspoređeni mogući načini prilagođenja malih antena – uskopojasno, pasivno prilagođenje te širokopojasno, aktivno, izvedeno nefosterovskim elementima. Provedena je simulacija aktivnog prilagođenja male antene sa serijski spojenim negativnim kondenzatorom, pri čemu je antena opisana Chuovim modelom, a negativni kondenzator ostvaren je negativnim konverterom impedancija u OCS konfiguraciji. Također, isprobano je i spajanje T-spoja pozitivnih i negativnih induktiviteta na ulaz aktivno prilagođene antene s ciljem transformacije otpora zračenja antene, koji kvadratno ovisi o frekvenciji, na konstantnu vrijednost. Konačno, matematički je opisan nastanak Huygensova izvora, električki kratke usmjerene antene, te su prikazani i uspoređeni rezultati simulacija i mjerenja iste.

Abstract (english)

In this Thesis, the basic properties of antennas necessary for understanding the task are presented. Following, the possible ways of small antenna matching are compared - narrowband, passive matching and wideband, active matching, performed with non-Foster elements. A simulation of the active matching of a small antenna with a negative capacitor connected in series is carried out, in which the antenna is described by Chu's model, and the negative capacitor is realized by a negative impedance converter in the open-circuit-stable configuration. Also, the idea of transforming radiation resistance of antenna to a constant value using an inductive T-dualizer was shown. Finally, the Huygens source, an electrically short directional antenna, is described mathematically, and the results of simulations and measurements of the antenna are presented and compared.

• Keywords: nefosterovski elementi; negativni pretvornik impedancije; Chuov model antene; prilagođenje antene; Huygensov izvor
• Keywords (english): non-Foster elements; negative impedance converter (NIC); Chu’s antenna model; antenna matching; Huygens source
• Language: croatian
• URN:NBN: urn:nbn:hr:168:478003
• Study programme: Title: Electrical Engineering and Information Technology; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra inženjer/inženjerka elektrotehnike i informacijske tehnologije (magistar/magistra inženjer/inženjerka elektrotehnike i informacijske tehnologije)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Closed access
• Created on: 2023-10-11 09:26:35