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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
71

Investigation, design and implementation of frequency tuneable antennas for mobile handset and UWB applications : simulation and measurement of tunable antennas for handheld mobile handsets and UWB system, investigations of frequency tuneable range, antenna radiation performance and antenna design optimisation using parametric studies

Elfergani, Issa T. January 2012 (has links)
No description available.
72

Analysis of feeding techniques of a patch antenna array for 5G NR / Analysis of feeding techniques of a patch antenna array for 5G NR

Kivk, Ji­ January 2021 (has links)
Tato diplomov prce se zabv anal­zou rznch napjec­ch struktur pro 2x2 fl­Äkov© antenn­ pole. Evaluace prob­h na stedn­ frekvenci 25.5GHz, kter spad do psma piazen©ho pt© generaci mobiln­ch komunikaÄn­ho standardu. Zvolen© napjec­ struktury byly napjen­ bl­zkm polem, napjen­ aperturou a napjen­ mikropskem.
73

Antény pro pásmo milimetrových vln / Antennas for milimeter-wave bands

Pítra, Kamil January 2010 (has links)
This thesis describes design and experimental verification of three types of the wideband antenna Bow-tie antenna, Vivaldi antenna and Spiral antenna. The tracked parameters are bandwidth, input impedance, gain and directivity patterns. Next step is design of millimeter-wave horn antennas. Attention is turned to the proper construction of a wideband feeder of the horn. For the final antenna structure, a bow-tie dipole and a Vivaldi antenna were chosen. The antenna construction is aimed to provide a wide bandwidth on one hand and a high gain on the other hand.
74

Vícevrstvá Yagiho anténa pro pásmo 60 GHz / Stacked Yagi antenna for 60 GHz frequency band

Janečka, Martin January 2013 (has links)
This diploma thesis deals with the design and simulation of multi-layer stacked Yagi antenna at the frequency of 60 GHz. At work are proposed and compared two ways of antenna feeding methods. Based on the results obtained, antenna is fed by substrate integrated waveguide. The proposed antenna has been optimized in terms of gain and impedance matching at the specified frequency. The correct functionality of the antenna was verified by simulation program CST MWS 2011. Simulation results were verified experimentally.
75

Tkané antény / Woven antennas

Fikar, Jan January 2015 (has links)
The thesis is aimed to design textile antennas that can operate in the ISM band 5.8 GHz. Attention is turned to practical exploitation of these antennas under regular conditions. Variations of the bandwidth of the antenna due to washing and waterproofing will be observed. Finally, the impact of the proximity of living tissue on the parameters of antennas will be studied.
76

Investigation, design and implementation of frequency tuneable antennas for mobile handset and UWB applications. Simulation and measurement of tunable antennas for handheld mobile handsets and UWB system, investigations of frequency tuneable range, antenna radiation performance and antenna design optimisation using parametric studies

Elfergani, Issa T. January 2012 (has links)
General Secretariat of Education and Scientific Research, Libya. / The only available copy is the print version kept in the J.B.Priestley Library for reference.
77

Design Methodology for Wideband Electrically Small Antennas (ESA) Based on the Theory of Characteristic Modes (CM)

Obeidat, Khaled Ahmad 26 August 2010 (has links)
No description available.
78

Low-Profile Wideband Antennas Based on Tightly Coupled Dipole and Patch Elements

Irci, Erdinc 21 October 2011 (has links)
No description available.
79

Super-Wide Impedance Bandwidth Planar Antenna for Microwave and Millimeter-Wave Applications

Alibakhshikenari, M., Virdee, B.S., See, C.H., Abd-Alhameed, Raed, Falcone, F., Limiti, E. 19 May 2019 (has links)
Yes / A feasibility study of a novel configuration for a super-wide impedance planar antenna is presented based on a 2 × 2 microstrip patch antenna (MPA) using CST Microwave Studio. The antenna comprises a symmetrical arrangement of four-square patches that are interconnected to each other with cross-shaped high impedance microstrip lines. The antenna array is excited through a single feedline connected to one of the patches. The proposed antenna array configuration overcomes the main drawback of conventional MPA with a narrow bandwidth that is typically <5%. The antenna exhibits a super-wide frequency bandwidth from 20 GHz to 120 GHz for S11 < −15 dB, which corresponds to a fractional bandwidth of 142.85%. The antenna’s performance of bandwidth, impedance match, and radiation gain were enhanced by etching slots on the patches. With the inclusion of the slot, the maximum radiation gain and efficiency of the MPA increased to 15.11 dBi and 85.79% at 80 GHz, which showed an improvement of 2.58 dBi and 12.54%, respectively. The dimension of each patch antenna was 4.3 × 5.3 mm2 . The results showed that the proposed MPA is useful for various existing and emerging communication systems such as ultra-wideband (UWB) communications, RFID systems, massive multiple-output multiple-input (MIMO) for 5G, and radar systems. / This work was partially supported by the Innovation Program under grant agreement H2020-MSCA-ITN-2016 SECRET-722424 and financial support from the UK Engineering and Physical Sciences Research Council (EPSRC) under grant EP/E022936/1.
80

Development of lightweight and low-cost microwave components for remote-sensing applications

Donado Morcillo, Carlos Alberto 11 January 2013 (has links)
The objective of the proposed research is to design, implement, and characterize low-cost, lightweight front-end components and subsystems in the microwave domain through innovative packaging architectures for remote sensing applications. Particular emphasis is placed on system-on-package (SoP) solutions implemented in organic substrates as a low-cost alternative to conventional, expensive, rigid, and fragile radio- frequency substrates. To this end, the dielectric properties of organic substrates RT/duroid 5880, 6002 and 6202 are presented from 30 GHz to 70 GHz, covering most of the Ka and V radar bands, giving also a thorough insight on the uncertainty of the microstrip ring resonator method by means of the Monte Carlo uncertainty analysis. Additionally, an ultra-thin, high-power antenna-array technology, with transmit/ receive (T/R) functionality is introduced for mobile applications in the X band. Two lightweight SoP T/R array panels are presented in this work using novel technologies such as Silicon Germanium integrated circuits and microelectromechanical system switches on a hybrid organic package of liquid crystal polymer and RT/duroid 5880LZ. A maximum power of 47 dBm is achieved in a package with a thickness of 1.8 mm without the need of bulky thermal management devices. Finally, to address the thermal limitations of thin-film substrates of interest (liquid crystal polymer, RT/duroid 6002, alumina and Aluminum Nitride), a thermal assessment of microstrip structures is presented in the X band, along with the thermal characterization of the dielectric properties of RT/duroid 6002 from 20 C to 200 C and from 30 GHz to 70 GHz. Additional high-power, X-band technologies presented in this work include: a novel and compact topology for evanescent mode filters, and low-profile Wilkinson power dividers implemented on Aluminum Nitride using Tantalum Nitride thin-film resistors.

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