Terahertzová anténní pole pro komunikaci

Abstract
The thesis is focused on the research of THz antenna arrays to be used for communications. Attention is turned to modeling metallic surfaces at THz frequencies, a proper characterization of gold conductivity, its relation to Drude model and corresponding measurements. Moreover, the best methods for modeling thin metallic layers (depending on the skin depth related to the metal thickness) are presented. An optimized element of a THz 2×2 antenna array designed for the application of communications is developed in a way that enables an expansion to a larger array. The expansion ability is demonstrated on a 4×4 antenna array which is presented in the thesis too. The designed antennas achieve parameters better than the state-of-art antennas. The presented antennas radiate circularly polarized wave at THz frequencies, operate in a wide bandwidth, have a high gain and are of a compact size. In the thesis, an 8×8 antenna array with a beam steering capability is presented. The main beam of the antenna array can be controlled in two dimensions. A high gain of the radiated circularly-polarized wave can be achieved that way. Different approaches to modeling antennas with thin metallic layers are compared and the best methods are recommended from the viewpoint of different requirements. The designed 2×2 and 4×4 antenna arrays are manufactured using a microfabrication technology. Each step of the fabrication is described in detail and discussed. The reflection coefficient at the input of antennas is measured and compared with simulations. Discrepancies in results are associated with surface roughness which is analyzed by a scanning probe microscope and a scanning electron microscope. By down-scaling the developed THz antenna, a low-profile high-gain antenna for Ka-band space applications is designed. The presented antenna achieves better results than state-of-art CubeSat antennas. The antenna performance is verified by a prototype to be operated at 9 GHz, and the radiation characteristics are experimentally confirmed.
The thesis is focused on the research of THz antenna arrays to be used for communications. Attention is turned to modeling metallic surfaces at THz frequencies, a proper characterization of gold conductivity, its relation to Drude model and corresponding measurements. Moreover, the best methods for modeling thin metallic layers (depending on the skin depth related to the metal thickness) are presented. An optimized element of a THz 2×2 antenna array designed for the application of communications is developed in a way that enables an expansion to a larger array. The expansion ability is demonstrated on a 4×4 antenna array which is presented in the thesis too. The designed antennas achieve parameters better than the state-of-art antennas. The presented antennas radiate circularly polarized wave at THz frequencies, operate in a wide bandwidth, have a high gain and are of a compact size. In the thesis, an 8×8 antenna array with a beam steering capability is presented. The main beam of the antenna array can be controlled in two dimensions. A high gain of the radiated circularly-polarized wave can be achieved that way. Different approaches to modeling antennas with thin metallic layers are compared and the best methods are recommended from the viewpoint of different requirements. The designed 2×2 and 4×4 antenna arrays are manufactured using a microfabrication technology. Each step of the fabrication is described in detail and discussed. The reflection coefficient at the input of antennas is measured and compared with simulations. Discrepancies in results are associated with surface roughness which is analyzed by a scanning probe microscope and a scanning electron microscope. By down-scaling the developed THz antenna, a low-profile high-gain antenna for Ka-band space applications is designed. The presented antenna achieves better results than state-of-art CubeSat antennas. The antenna performance is verified by a prototype to be operated at 9 GHz, and the radiation characteristics are experimentally confirmed.
Description
Citation
WARMOWSKA, D. Terahertzová anténní pole pro komunikaci [online]. Brno: Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií. 2020.
Document type
Document version
Date of access to the full text
Language of document
en
Study field
Elektronika a sdělovací technika
Comittee
prof. Ing. Aleš Prokeš, Ph.D. (předseda) doc. Ing. Libor Dražan, CSc. (člen) doc. Ing. David Vrba, Ph.D. (člen) doc. Ing. Václav Kotlan, Ph.D. (člen) doc. Ing. Jaroslav Láčík, Ph.D. (člen) prof. Miroslav Joler - oponent (člen) Ing. Michal Pokorný, Ph.D. - oponent (člen)
Date of acceptance
2020-09-01
Defence
Práce Ing. Dominiky Warmovské se zabývá vývojem antén pro komunikaci v terahertzových pásmech, porovnáním přístupů pro modelování metalických povrchů a zobecněním návrhových metod pro mikrovlnná pásma. Dizertační práce splňuje v důležitých aspektech stanovené cíle, přináší nové poznatky a metody v oblasti návrhu anténních polí . Doktorandka spojila ve své práci teoretické znalosti s technicko-inženýrskými schopnostmi a potvrdil tak svoji schopnost samostatné vědecké práce na velmi dobré úrovni. Komise se jednomyslně usnesla na závěru, že Ing. Dominika Warmovská splnila cíle dizertační práce a dosaženými výsledky a publikační činností splnila podmínky k udělení akademického titulu doktor.
Result of defence
práce byla úspěšně obhájena
Document licence
Standardní licenční smlouva - přístup k plnému textu bez omezení
DOI
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