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Tzortzakakis, Michail. "Multi-band antennas for mobile phones." Thesis, University of Sheffield, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.434598.
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Xu, Hang. "Multi-band small antennas for mobile terminals." Thesis, University of Kent, 2018. https://kar.kent.ac.uk/71284/.
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The thesis presents several novel ideas of designing electrically small antennas for mobile terminals such as mobile phones. As the fifth generation wireless systems (5G) is coming soon, radio signals at sub 6 GHz and millimetre-wave (mmWave) frequencies will be employed in mobile communication. In this thesis, the author concentrates on the antennas at sub 6 GHz, because the signals at sub 6 GHz will still play an important role in 5G mobile communication due to the advantage of signal penetration through buildings. The research areas consist of main antenna and multi-input multi-output (MIMO) antenna technology including decoupling techniques and MIMO antenna unit. First, a novel six-mode loop antenna as a main antenna is proposed for mobile phones. Loop antennas offer better user experience than monopole antennas, inverted-F antennas (IFA), and planar inverted-F antennas (PIFA) because of the unique balanced modes (1λ, 2λ, ...). However, the balanced modes also cause narrower bandwidth of loop antennas. In order to overcome the bandwidth problem, how to reach the upper limit of the existing operating modes and how to create more modes are explored. A novel monopole/dipole parasitic element, which operates at an unbalanced monopole-like 0.25λ mode and a balanced dipole-like 0.5λ mode, is firstly proposed. In order to validate the concept, one prototype with the dimension of 75×10×5 mm3 is designed, fabricated, and measured. The antenna is able to cover 660-1100 MHz, 1710-3020 MHz, 3370-3900 MHz, and 5150-5850 MHz, which is wide enough for almost all the service of mobile telecommunication systems. Then, a multimode decoupling technique is proposed for wideband/multiband isolation enhancement in compact volume. Although decoupling techniques have been researched for many years, multimode decoupling technique remains a great challenge for mobile terminals. One difficulty in achieving multi decoupling modes is that the operating modes of closely-packed decoupling elements have very strong mutual effect, which makes the tuning complicated and even unfeasible. Thus, in physical principle, a novel idea of achieving the stability of the boundary conditions of decoupling elements is proposed to solve the mutual effect problem; in physical structure, a metal boundary is adopted to realize the stability. One distinguished feature of the proposed technique is that the independent tuning characteristic can be maintained even if the number of decoupling elements increases. Therefore, wideband/multiband high isolation can be achieved by isolating multi decoupling elements. To validate the concept, two case studies are given. In a quad-mode decoupling design, the isolation is enhanced from 12.7 dB to > 21 dB within 22.0% bandwidth by using a 0.295λ0×0.059λ0×0.007λ0 decoupling structure. Finally, a novel principle, namely differential/common mode (DM/CM) design, is proposed to achieve highly integrated MIMO antenna unit in mobile terminals. The inspiration comes from a dipole fed by a differential line which can be considered as differential mode (DM) feed. What will happen if the DM feed is transformed into a common mode (CM) feed? Some interesting features are found in the research. By symmetrically placing one DM antenna and one CM antenna together, a DM/CM antenna can be achieved. Benefitting from the coupling cancellation of anti-phase currents and the different distributions of the radiation currents, a DM/CM antenna can obtain high isolation and complementary patterns, even if the radiators of the DM and CM antennas are overlapped. Therefore, good MIMO performance can be realized in a very compact volume. To validate the concept, a miniaturized DM/CM antenna unit is designed for mobile phones. 24.2 dB isolation and complementary patterns are achieved in the dimension of 0.330λ0×0.058λ0×0.019λ0. One 8×8 MIMO antenna array is constructed by using four DM/CM antenna units and shows good overall performance. The proposed idea of DM/CM design may be promising for other applications that need high isolation and wide-angle pattern coverage.
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Yin, Jungang. "Multi(Wide)-Band Multi-Functional Antennas Based On Folded Dipoles." Doctoral thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for elektronikk og telekommunikasjon, 2011. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-14600.
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This doctoral thesis deals with designs and developments of multi(wide)-band multifunctional antennas based on folded dipoles. In the beginning, the concept of Orthogonal Folded Dipoles (OFD) are put forward. Orthogonal folded dipoles are formed by two identical two-port folded dipoles orthogonally joining with each other at the center, and can be fed through different combinations of feed nodes to offer dual- and wide-band modes, respectively. The impedances of the 2 modes are studied both by analytical models and by commercial electromagnetic simulation tools. The properties of the linearly polarized radiation patterns in the two modes vary quite little, except for ±45◦ rotation of two principal planes. In this way, orthogonal folded dipoles can possibly provide pattern reconfigurability in a context of switchable types and orientations of polarizations. Next, the concept of Log-Periodic Folded Dipole Array (LPFDA) is proposed. It stems from the traditional log-periodic dipole array, whereas folded dipoles instead of straight dipoles are applied as the elements of the array. Two configurations, i.e. partly-scaled LPFDA and fully-scaled LPFDA, are studied through simulations and optimizations. The comparison shows that the latter outperforms the former in terms of higher directivity, reduced front-to-back ratio and lower crosspolar level. The key parts of this thesis focus on exploiting Eleven antennas, based on the LPFDAs, in a variety of applications. First, the 4-port L-band lab model for use in satellite terminals demonstrates that the radiation patterns for monopulse tracking can be achieved through different excitation combinations of the multiport Eleven antenna. Second, a decade bandwidth, an unchanged phase center and nearly constant directivities over the whole band can be regarded as the major figure-of-merit of the Eleven antenna, which makes it suitable as feed for prime-fed reflector antennas. Through endeavors of using Genetic Algorithms, the wideband Eleven antennas have been gradually optimized in term of matching as well as efficiencies. Besides, the rotationally symmetric circular Eleven feed is a very promising solution for improving the BOR1 efficiency and therefore the aperture efficiency by a fraction of dB. Last but not least, the two multiport L-band lab models measured in a reverberation chamber demonstrate that the Eleven antenna with MIMO diversity ports can possibly overcome narrowband multipath fading in a real radio link and improve the link quality in terms of a significant diversity gain and high maximum available capacity.
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Abdelaziz, Abdelaziz Abdelmonem. "Compact multi-band microstrip planar antennas and arrays." Thesis, Cranfield University, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.315345.
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Hussien, Khairi Mutaz Hamed. "Study of multi-band and ultra-wide band antennas (6-8.5 GHz)." Thesis, Linköpings universitet, Institutionen för teknik och naturvetenskap, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-96299.
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Since the United Sate Federal Communication Commission (FCC) released the first Ultra Wide-band (UWB) report on February 14, 2002, the interest in UWB technology has increased substantially in both academia and industry. Interest is to simulate by the expectation that UWB can solve the shortage of the available frequency recourses. The European Electronics Communications Committee (ECC) has approved the use of UWB devices in the range from 6-8.5 GHz, subjected to the technical limits embossed by FCC in the US. Therefore one of the main goals is to find an optimal planar-antenna working in the European (UWB) spectrum 6-8.5 GHz, with a bandwidth of 2.5 GHz. The different ntypes of antennas investigated are the dipole antenna, the square antenna (basic square antenna, square antenna with bevel, square with off set) and the circular disc antenna, designed and simulated in Advance Design System (ADS). Planar antennas implemented in this project have a multi layer PCB structure which includes a flexible foil. The design process is mainly carried out in two steps. In the first step dimensions of antennas were calculated, then in the second step dimensions were tuned until the simulation result fulfilled the demands of the design specification. The characteristic input impedance, bandwidth, gain, directivity and electromagnetic radiation pattern are compared among different types of planar antennas investigated. In this report the bandwidth the focus because it the major concern of the project. The Balun is used to adapt the signal between the antenna and the device (transmitter and receiver). When the Balun simulated together with a planar antenna small change in the bandwidth is observed. It found that there are four types of planar antennas (basic square antennas, square antenna with bevel, square antenna with offset and circular disc antenna) can be used in the Ultra Wideband spectrum 6-8.5 GHz .
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Temple, Kip, Robert Jefferis, and Robert Selbrede. "PERFORMANCE CHARACTERIZATION OF MULTI-BAND ANTENNAS FOR AERONAUTICAL TELEMETRY." International Foundation for Telemetering, 2007. http://hdl.handle.net/10150/604568.
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ITC/USA 2007 Conference Proceedings / The Forty-Third Annual International Telemetering Conference and Technical Exhibition / October 22-25, 2007 / Riviera Hotel & Convention Center, Las Vegas, Nevada<br>This paper baselines the performance of common, single band telemetry blade antennas in two telemetry
bands and compares that performance to two very differing multi-band antenna designs. A description
of each antenna is presented followed by flight testing results and conclusions. Results are in the form of
received signal strength versus geographic location, derived in-flight antenna patterns, link availability,
and bit error analysis.
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Starke, Philip Llewelyn. "Analysis and optimisation techniques for multi-band printed base station antennas." Thesis, University of Sheffield, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.401190.
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Baek, Seung Hoon. "STUDY OF MULTI- AND BROAD-BAND INTERNAL ANTENNAS FOR MOBILE APPLICATIONS." OpenSIUC, 2011. https://opensiuc.lib.siu.edu/dissertations/424.
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The modified aperture coupled MicroStrip Antenna (MSA) and Planar Inverted F Antenna (PIFA) for mobile applications are studied and presented in this dissertation. The designed antennas are improved multi-band and broad-band characteristics by the modification of radiating elements and/or the ground plane. The novel modified aperture coupling annular-ring antenna fed by stripline is the hybrid structure of the aperture coupling feed MSA and the proximity feed MSA. The proximity feed enable to concentrate the field strength toward the direction of the radiating element and the modified aperture layer contributes to provide the maximum coupling to the radiating element. The measurement bandwidths of the Aperture Coupling Proximity Feed Hybrid MSA #1(ACPF-HMSA#1, design #1) and ACPF-HMSA #2 (design #2) are 185MHz (7%) and 105MHz (4.1%), VSWR in less than 2, respectively. Two layers Planar Inverted F Antenna (PIFA) with the modification of the ground and radiating element was studied. The inserted T-shaped or L-shaped ground and inserted a slot and slits on radiating elements help to adjust the resonant frequencies to the target applications. The result of PIFA #3 (design #3) is presented a significant board-band characteristic on the upper band by 910MHz (from 1.45GHz to 2.36GHz) with VSWR less than 2.5. It covers GPS, DCS, PCS, and UMTS bands. Novel internal loop planar inverted F antennas (L-PIFA) with Inserted Concentrated Annular Rings (ICAR) and Inserted Loop Inductors (ILI) are presented as design #4 (ICAR-L-PIFA #4) and design #5 (ILI-L-PIFA #5), respectively. The simple loop structure consists of a meandered line. It increases the capacitance between adjacent lines. The Inserted annular-rings and loop inductors provide inductance values to the main loop antennas. Therefore, the impedance bandwidth of the design #4 is 570MHz (from 1.69GHz to 2.26GHz) with VSWR less than 2.5. And, the impedance bandwidth of the design #5 is 275MHz (from 1.63GHz to 1.905GHz) and 465MHz (from 2.19GHz to 2.655GHz) with VSWR less than 2.5.
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Kacar, Merve. "Direct Digital Manufacturing of Multi-layer Wideband Ku-band Patch Antennas." Scholar Commons, 2017. https://scholarcommons.usf.edu/etd/7411.
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Design and performance of fully-printed Ku-band aperture coupled patch antennas fabricated by a direct digital manufacturing (DDM) approach that integrates fused deposition modeling (FDM) of acrylonitrile butadiene styrene (ABS) thermoplastic with in-situ micro-dispensing of conductive silver paste (CB028) are reported. Microstrip line characterizations are performed and demonstrate that misalignment of ABS substrate deposition direction with microstrip line micro-dispensing direction can degrade the effective conductivity up to 60% within the Ku-band, and must be taken into consideration in antenna array feed network designs. Specically, over 125 µm thick ABS substrate, RF loss of 0.052 dB/mm is obtained at 18 GHz, demonstrating the feasibility of additively manufactured RF devices within the Ku-band. By varying ABS inll ratios and resorting to multi-layer printing with custom substrate thicknesses, single and stacked patch antennas are designed, fabricated, and characterized with bandwidth performances up to 35%, and radiation efficiencies up to 90%. This extensive utilization of the design flexibilities provided by the direct digital manufacturing (i.e. customized substrate thicknesses, multiple substrates with varying infill ratios, and in-situ micro-dispensing of conductors) distinguishes the present work from the recently reported 3-D printed antennas. Compared to the existing work in literature, the antennas presented within this thesis stand out as being fully printed structures, operating in higher frequency range (i.e. Ku-band), and exhibiting high radiation efficiencies with wide bandwidth performances.
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Kujiraoka, Scott, Russell Fielder, and Maxim Apalboym. "Spectrum Access R&D (SARD) Program: Conformal C-Band/Multi-band Antenna Project." International Foundation for Telemetering, 2016. http://hdl.handle.net/10150/624194.
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The Conformal C-Band/Multi-band Antenna project will support the AWS-3 auction by
providing the technology to integrate C-Band or multi-band telemetry(TM) antennas on
test articles such as missiles, weapons, or aircraft. These test articles would then
provide C-Band or multi-band TM data to ground station receivers that are relocated to
the C-Band frequency range through the AWS-3 Spectrum Relocation Fund program.
This project would advance the technology of antennas in the C-Band region for test
article TM integration. Successful use of C-Band and Multi-Band antennas for
aeronautical mobile telemetry (AMT) on test and training ranges is dependent on the
advancement of key technologies. This paper will detail the technology areas being
matured by this project as well as the capabilities to be demonstrated.
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Kujiraoka, Scott, Russell Fielder, Maxim Apalboym, and Michael Chavez. "Spectrum Access R&D (SARD) Program: An Update on the Conformal C-Band/Multi-band Antenna Project." International Foundation for Telemetering, 2017. http://hdl.handle.net/10150/626948.
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In September 2016, work was initiated on the subprojects which comprise the Conformal C-Band/Multiband Antenna project: SARD #1: Broadband Conformal C-Band Missile Wraparound Antennas; SARD #2: Beam Switching Array Antennas; SARD #3: Multiband Conformal Antennas for Aircraft Applications; SARD #4: High Altitude Coronal Efforts on Antenna Performance; and SARD #5: Small, Medium Gain Multiband Receive Antennas. A brief status of each of them will be discussed and detail the technology areas being developed by each.
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Abou-Zied, Nour Amro. "Study, design and realization of circular polarized compact antennas : Optimizing performances." Thesis, Limoges, 2016. http://www.theses.fr/2016LIMO0027.
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Les antennes à polarisation circulaire (CP) sont de plus en plus utilisées dans les systèmes de communications spatiaux et terrestres. Le besoin d’intégration est sans cesse plus important, il est donc nécessaire de proposer, de mettre au point des aériens toujours plus compacts et aux performances (adaptation, rayonnement, gain, efficacité, taux d’ellipticité) optimisées. L’objectif de cette thèse est donc de concevoir des antennes planaires, large bande ou multi-bande, à polarisation circulaire et aux performances optimisées. Afin d’atteindre ces objectifs, le travail a été divisée en plusieurs phase, allant de la conception d’une antenne CP à large bande jusqu’à la conception d’une antenne patch à polarisation circulaire tri bandes GNSS. Tout d’abord une étude bibliographique sur les antennes planaires a été faite. Celle-ci a permis de comparer leurs différentes performances, leurs avantages et inconvénients. Ensuite, une antenne patch CP à éléments parasites a été conçue fabriquée et mesurée. On s’est attaché à optimiser sa bande de fonctionnement. En tenant compte des études bibliographiques déjà faites, et en se basant sur la structure de l’antenne CP à large bande validée lors de la phase précédente, une nouvelle antenne plaquée CP GNSS tri bandes a également été conçue réalisée et mesurée. L’essentiel du travail a consisté à minimiser son encombrement tout en conservant des performances électromagnétiques satisfaisantes dans les trois bandes de fréquences objectifs : L2, E6 et L1. On s’est particulièrement attaché à obtenir un bon taux d’ellipticité sur une large ouverture rayonnante. La dernière étape de cette thèse a consisté à aller encore plus loin dans l’amélioration des performances de l’antenne CP GNSS multi bandes particulièrement en améliorant son efficacité. Une excitation par fente a finalement été utilisée après comparaison des performances obtenues via différentes techniques (alimentation coaxiale, fentes, etc…)<br>Circular polarized antennas (CP) are greatly used in space and terrestrial communication systems. Furthermore, the need for communication systems integration is increasingly important. Therefore, it is necessary to propose and develop more compact antenna design with optimized performance (adaptation, radiation, gain, efficiency, axial ratio).The objective of this thesis is to design planar antennas, broadband or multi-band, with circular polarization and optimized performances. To achieve these objectives, the work was divided into several stages, from the design of a wideband CP antenna to the design of a GNSS tri-band circular polarized patch antenna. Firstly, a literature study of planar antennas has been conducted. Different designs have been examined and contrasted to evaluate their performances. Secondly, a wideband CP patch antenna with parasitic elements has been designed manufactured and measured. It was sought to optimize its operating band. Considering the bibliographical study that was already carried out, and based on the wideband CP antenna structure that was validated during the previous phase, a new GNSS tri-band CP patch antenna was also designed, fabricated and measured. Most of the work was done on minimizing its size while maintaining satisfactory electromagnetic performance in the three required GNSS frequency bands : L2, E6 and L1. Special attention was directed towards getting a good axial ratio over a wide radiating aperture. The last phase of this thesis was to go even further in improving the CP GNSS multi-band antenna's performance, particularly by improving its efficiency. Excitation slots were finally used after a comparison was made between the different performances obtained through the different design techniques (coaxial feed, slots, etc ...)
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Gupta, Saurabh. "Miniature Printed Antennas and Filters Using Volumetric Reactive Pins and Lumped Circuit Loadings." Scholar Commons, 2014. https://scholarcommons.usf.edu/etd/5369.
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This dissertation presents a new technique for miniaturization of printed RF circuits and antennas. The technique is based on lumped circuit elements and volumetric reactive pin loadings. The vertical arrangement of the pins is shown to provide a meandered current path within the device volume enhancing the miniaturization achieved with sole application of lumped circuit components. The technique is applied for antenna and filter size reduction. In antenna applications, it is shown that due to the presence of the reactive pin loading the overall size of a printed antenna can be miniaturized without affecting the radiation efficiency performance. One of the major advantages of this approach over the existing miniaturization techniques is that it allows reducing the overall size of the antenna (i.e. the substrate size) in addition to its metallization footprint area. Specifically, three antenna designs are presented for GPS and ISM applications. Firstly, a miniaturized wide-band CDL antenna has been introduced. The antenna consists of two loops which are loaded with lumped inductors and coupling capacitors. The design is shown to exhibits 49% smaller footprint size as compared to a traditional patch antenna without degrading the bandwidth performance. Secondly, a circular polarized compact dual-band CDL GPS antenna loaded with lumped capacitors and vertical pins is shown. The antenna operates with >50% lesser area as compared to a traditional L2 patch antenna without degrading its radiation performance. Thirdly, a patch antenna with its cavity loaded with CSRRs is presented. The novelty of the design is that it provides circularly symmetric arrangement of CSRRs thereby enabling the antenna to exhibit circular polarization (CP). Apart from CSRR, further size reduction is obtained by simultaneously reducing the substrate size and ground plane metallization around the CSRRs and loading it with pins. The antenna is 44% smaller than a traditional patch antenna without causing degradation in the antenna's radiation efficiency performance. To extend the volumetric loading to filter applications, the last chapter of the dissertation presents a detailed analysis to understand how geometrical factors (e.g. periodicity, radius, width of the host transmission line, etc) affect the miniaturization performance and quality factor. As a design example, a 2GHz pin loaded hairline filter with 17% -3dB |S21| bandwidth and 1.5dB insertion loss is demonstrated. The footprint size of the filter is ~λ0/16×λ0/9 @ 2GHz and is 45% smaller than its traditional counterpart.
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Dimitrov, Emil [Verfasser]. "System design and validation of multi-band OFDM wireless communications with multiple antennas / Emil Dimitrov." Hannover : Technische Informationsbibliothek und Universitätsbibliothek Hannover (TIB), 2013. http://d-nb.info/1036694151/34.
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Wang, Xiaojing. "Multi-resolution time-domain modelling technique and its applications in electromagnetic band gap enhanced antennas." Thesis, Queen Mary, University of London, 2010. http://qmro.qmul.ac.uk/xmlui/handle/123456789/380.
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Newly emerged Electromagnetic Band Gap (EBG) structures possess multiple frequency bands that prohibit wave propagation and such stop bands are basically determined by the periodicity of the structure. Such desirable features make EBG hybrid antenna an interesting topic. Traditional full-wave techniques lack the efficiency to fully cope with the complexity of these hybrid structures, since the periodical elements are often much smaller in size than the accompanying antenna components. The Haar wavelet based Multi-Resolution Time Domain (MRTD) technique provides improved numerical resolution over the conventional Finite-Difference Time-Domain (FDTD) method, as well as simplicity in formulation. One-dimensional, two-dimensional and three-dimensional level-one codes are developed to assist the numerical modelling of the hybrid EBG antennas. An explicit form of Perfectly Matched Layer (PML) configuration is proposed, proved and presented. As a generic approach, its extensions suit every single level of Haar wavelet functions. A source expansion scheme is proposed thereafter. The concept of a multi-band multi-layer EBG hybrid antenna is presented. The theoretical prediction of antenna resonances is achieved through an effective medium model. It has been verified via numerical simulations and measurements. The 3D MRTD code is later applied to simulate such a structure. In addition, EBG enhanced circularly polarized photonic patch antennas have been studied. It is demonstrated that split-resonant rings (SRRs) and the like in EBG antennas can lead to antenna gain enhancement, backward radiation reduction and harmonic suppression. Furthermore, a circularly polarized two-by-two antenna array with spiral EBG elements is presented. The spiral element with ground via is more compact in size than the traditional mushroom structure, which is proven very efficient in blocking unwanted surface wave. Hence it reduces the mutual coupling of the array antenna significantly.
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Bulgaroni, Renan Guimarães. "Projeto de antenas planares de baixo custo para sistemas Multibanda." reponame:Repositório Institucional da UFABC, 2016.
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Orientador: Prof. Dr. Ivan Roberto Santana Casella<br>Dissertação (mestrado) - Universidade Federal do ABC, Programa de Pós-Graduação em Engenharia Elétrica, 2016.<br>Este trabalho visa o desenvolvimento de antenas planares multibanda de baixo custo para aplicações em sistemas de comunicações sem fio. As antenas propostas, baseadas nas topologias Quasi-Yagi e Vivaldi para sistemas SISO (Single Input Single Output) e Meandered Loop para sistemas MIMO (Multiple Input Multiple Output), foram otimizadas para operar nas faixas de frequência das redes LTE (Long Term Evolution), WiFi (Wireless Fidelity) e WIMAX (Worldwide Interoperability For Microwave Access). Após os estudos preliminares de simulação e otimização para a definição final das topologias propostas, foram montados alguns protótipos para a realização de testes de medida e comprovação experimental das funcionalidades das antenas.<br>This work is aimed at developing low-cost multiband planar antennas for applications in wireless communications systems. Antennas proposals based on Quasi-Yagi topologies and Vivaldi for SISO systems (Single Input Single Output) and meandered Loop for MIMO (Multiple Input Multiple Output) were optimized to operate in the frequency bands of the LTE (Long Term Evolution), WiFi (Wireless Fidelity) and WIMAX (Worldwide Interoperability For Microwave Access). After the preliminary studies simulation and optimization for the final definition of the proposed topologies, some prototypes were assembled to perform measurement tests and experimental verification of the functionalities of antennas.
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Saraereh, Omar Aqeel. "The design of multi-band planar inverted-F antennas for mobile handsets with the aid of a novel genetic algorithm and their specific absorption rate." Thesis, Loughborough University, 2005. https://dspace.lboro.ac.uk/2134/34701.
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Wireless communications have progressed very rapidly in recent years and mobile handsets are becoming smaller and smaller. Present-day mobile cellular communication systems include combinations of the AMPS, GSM-900, DCS-l800, PCS-1900, UMTS, and WLANs in the 2.4GHz and 5.2GHz bands. User requirements for access to the various aforementioned wireless telecommunication services have resulted in a rapid technological push to unify these different systems in a drastically decreased size single mobile handset. All this combined with strict limitations set for the energy absorbed by the users of mobile terminals has created a need for improved antenna solutions and better understanding of small antennas. The objective of this thesis is to develop novel multi-band handset antenna design solutions to satisfy the specific bandwidth requirements of mobile cellular communication systems.
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Seko, Murilo Hiroaki. "Antenas planares de micro-ondas multibandas para terminais móveis de sistemas de comunicação sem fio." Universidade de São Paulo, 2013. http://www.teses.usp.br/teses/disponiveis/3/3140/tde-31072013-002544/.
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Neste trabalho, foram desenvolvidas antenas planares de micro-ondas multibandas para aplicação em terminais móveis de sistemas de comunicação sem fio. Foi realizado um estudo sobre antenas planares de micro-ondas, com ênfase em técnicas de projeto que possibilitam a operação das mesmas em bandas largas e em múltiplas bandas. A partir dos conhecimentos adquiridos com esse estudo, foram propostas configurações de antenas para terminais móveis de sistemas atuais de telefonia móvel, de WLAN e de WPAN, sistemas esses que têm experimentado nos últimos anos uma grande popularização mundial. Por meio de um procedimento de projeto auxiliado por simulação eletromagnética computacional, as configurações propostas de antenas foram analisadas e otimizadas, visando atender às especificações de projeto estabelecidas para operação nos sistemas mencionados. O desempenho que pode ser obtido com essas configurações de antenas depende de diversos parâmetros geométricos das mesmas, resultando em flexibilidade de projeto para obtenção das bandas de operação desejadas. Protótipos das antenas projetadas foram construídos e caracterizados para validar as configurações propostas de antenas e o procedimento de projeto empregado. Foram desenvolvidas quatro antenas para operação em sistemas de telefonia móvel, de WLAN e de WPAN empregados no Brasil, na Europa e nos EUA: uma antena planar em F-invertido tri-band com configuração original para operação nas bandas dos padrões GSM, DCS e PCS; uma antena planar em F-invertido penta-band com configuração original para operação nas bandas dos padrões GSM, DCS, PCS e UMTS e na banda ISM de 2.400 MHz; duas antenas quad-band, uma delas planar em F-invertido e a outra monopolo impresso com configuração original, para operação nas bandas ISM de 2.400 MHz e de 5.800 MHz e nas bandas de 5.200 MHz e de 5.600 MHz. Os resultados experimentais dos protótipos construídos apresentaram, de modo geral, boa concordância com os resultados fornecidos por simulação e mostraram que as antenas desenvolvidas atenderam às especificações de projeto para elas estabelecidas. Por meio de ambos os resultados experimentais e de simulação, o desempenho das antenas desenvolvidas pôde ser verificado, e demonstrou-se a efetividade do procedimento de projeto adotado.<br>In this work, multi-band microwave planar antennas for application in mobile terminals of wireless communication systems were developed. A study on microwave planar antennas was performed with emphasis on design techniques that enable their operation in wide bands and multiple bands. From the knowledge gained from this study, antenna configurations for mobile terminals of current mobile telephony, WLAN and WPAN systems, which have experienced in recent years great popularity worldwide, were proposed. By means of a design procedure aided by computer electromagnetic simulation, the proposed antenna configurations were analyzed and optimized in order to meet the design specifications established for operation in the afore mentioned systems. The performance that can be obtained with these antenna configurations depends on their several geometric parameters, resulting in design flexibility for obtaining the desired operation bands. Prototypes of the designed antennas were fabricated and characterized to validate the proposed antenna configurations and the design procedure employed. Four antennas were developed for operation in mobile telephony, WLAN and WPAN systems employed in Brazil, Europe and USA: a tri-band planar inverted-F antenna with novel configuration for operation in GSM, DCS and PCS standard bands; a penta-band planar inverted-F antenna with novel configuration for operation in GSM, DCS, PCS and UMTS standard bands and 2,400 MHz ISM band; two quad-band antennas, one of them planar inverted-F and the other printed monopole with novel configuration, for operation in 2,400 MHz and 5,800 MHz ISM bands and 5,200 MHz and 5,600 MHz bands. The experimental results from the fabricated prototypes exhibited, in general, good agreement with the results provided by simulation and showed that the developed antennas met the specifications established for them. By means of both simulation and experimental results, the performance of the developed antennas could be verified, and the effectiveness of the design procedure adopted was demonstrated.
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Santamaria, Luca. "Systèmes d'antennes reconfigurables intégrés dédiés aux réseaux IoT sans fil dynamiques." Thesis, Université Côte d'Azur, 2021. http://www.theses.fr/2021COAZ4103.
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De par les caractéristiques uniques de l'Internet des objets (IoT), telles qu'un volume massif de données, des contraintes de ressources strictes et des niveaux d'activité hétérogènes, les futures infrastructures IoT sans fil doivent intégrer des solutions d'auto-organisation intelligentes pour fonctionner efficacement dans l'environnement IoT dynamique.Dans ce contexte, cette thèse présente le développement de systèmes d'antennes intégrés reconfigurables innovants capables de s'adapter à de tels réseaux IoT sans fil dynamiques et polyvalents.Dans un premier temps, ce manuscrit de thèse traite de la conception d'antennes adaptées à une intégration dans des terminaux IoT lorsque des propriétés de rayonnement spécifiques ou des opérations multi-bandes sont nécessaires. Les structures d'antennes et les techniques d'intégration sont présentées pour les applications IoT à bande unique et multibande. Dans ce cadre, une méthodologie de conception basée sur une antenne à structure unique multi-accès et une antenne à polarisation circulaire omnidirectionnelle miniaturisée pour les applications IoT sont décrites. Ensuite, une approche basée sur les réseaux de neurones pour estimer les performances de petites antennes compte tenu des contraintes pratiques est présentée. Comme preuve de concept, le cas des antennes imprimées intégrées dans des terminaux compacts est étudié.Dans une seconde partie, la thèse porte sur le développement d'antennes reconfigurables compactes et peu gourmandes en énergie. Afin de permettre de nouvelles applications, telles que les communications portables, et d'offrir des performances supérieures dans une variété d'environnements d'intégration, une antenne flexible et reconfigurable est présentée. Pour garantir un fonctionnement fiable, les antennes flexibles doivent en effet conserver des caractéristiques radioélectriques ou de rayonnement approprié et ceci, malgré la modification de leur structure créée par la flexibilité. Le mécanisme de reconfiguration de l'antenne proposée pour les contraintes évoquées permet le décalage de sa résonance, la rendant ainsi capable de maintenir une adaptation d'impédance acceptable sur toute la bande de fonctionnement même lorsqu’elle est repliée.Une antenne compacte reconfigurable à gain et rapport avant/arrière élevés pour le filtrage spatial dans les réseaux IoT est ensuite proposée. Le mécanisme de reconfiguration est basé sur l'utilisation d'un commutateur SP4T à faible pertes d’insertion et à faible résistance, qui peut être contrôlé numériquement par un microcontrôleur, comme l'exigent les applications IoT. Une antenne à réseau parasite, avec faisceau orientable électroniquement (ESPAR, pour electronically steerable parasitic array radiator), à base d’éléments rayonnants de type fentes adaptée aux applications IoT est ensuite présentée. Le travail décrit en profondeur la procédure de conception de l'antenne, en abordant également la mise en œuvre pratique du mécanisme de reconfiguration, et se concentrant sur la réalisation du prototype et sa caractérisation expérimentale.Enfin, une méthodologie de synthèse de réseaux d'antennes parasites est proposée. Cette méthode est basée sur l'utilisation d'un algorithme de type PSO (Particle Swarm Optimizer), qui optimise de manière itérative les impédances complexes des charges connectées sur les éléments parasites jusqu'à ce que le comportement en rayonnement souhaité soit obtenu. Afin d'évaluer la capacité de la méthode à atteindre les objectifs souhaités, la méthodologie est utilisée pour optimiser la directivité, le rapport avant/arrière et le gain d’antennes à réseau parasite compactes destinées aux appareils IoT. Les valeurs des impédances de charge identifiées avec cette approche sont intégrées dans les structures d'antenne pour réaliser le réseau d'antennes parasites. La reconfiguration peut alors être simplement obtenue en réalisant une permutation circulaire des valeurs de la charge sur les éléments parasites<br>Because of the unique characteristics of the Internet of things (IoT), such as massive volume of data, stringent resource constraints, and heterogeneous activity levels, future wireless IoT infrastructures must integrate smart self-organizing solutions to efficiently operate in the dynamic IoT environment.Within this context, this thesis presents the development of innovative integrated reconfigurable antenna systems capable of adapting to such dynamic and multi-purposed wireless IoT networks.As a first step, the thesis covers the design of antennas suitable for integration in IoT terminals when specific radiation properties or multi-band operations are needed. Both antenna structures and integration techniques are presented for single and multi-band IoT applications. Next, a design methodology based on a multi-access single structure antenna and a miniaturized omnidirectional circularly polarized antenna for IoT applications are presented. Successively, an approach based on Neural Networks (NN) to estimate the performance of small antennas given practical constraints is presented. As proof of concept, the case of printed antennas integrated into compact terminals is considered.In the second part, the thesis focuses on the development of compact and low-power-consuming reconfigurable antennas. In order to enable new applications, such as wearable communications, and to deliver higher performance in a variety of integration environments, a flexible, reconfigurable antenna is presented. To guarantee reliable operation, flexible antennas must maintain proper electrical or radiation characteristics despite the variation of their structure given by the flexibility. Consequently, the reconfiguration mechanism of the proposed antenna allows the shift of the antenna resonance, making the antenna capable of maintaining an acceptable impedance matching over the operating band even when the antenna is folded.A compact high gain and front-to-back ratio pattern reconfigurable antenna for spatial filtering in IoT networks is then proposed. The reconfiguration mechanism is based on the use of a low-insertion, low-on resistance SP4T switch, which can be numerically controlled by a microcontroller, as required by IoT applications. Successively, a slot-based electronically steerable parasitic array radiator (ESPAR) antenna suitable for IoT applications is presented. The work describes in-depth the design procedure of the antenna, addressing the practical implementation of the reconfiguration mechanism, and focusing on the realization of the prototype and its experimental evaluation.Finally, a methodology for synthesizing parasitic antenna arrays is proposed. The method is based on the use of a Particle Swarm Optimizer (PSO), which iteratively optimizes the parasitic element loads until the desired pattern behavior is obtained. In order to assess the method's ability to address the desired goals, the methodology is used to optimize the directivity, the front-to-back ratio, and the gain of compact parasitic array antennas for IoT devices. The impedance loads values identified with this approach are integrated into the antenna structures to realize the parasitic antenna array. Reconfiguration can then simply be obtained by rotating the load's values over the parasitic elements
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Kuan-ChuanHuang and 黃冠銓. "Embedded Multi-Band Antennas Design." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/25973629469767926468.
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碩士<br>國立成功大學<br>電機工程學系碩博士班<br>98<br>Two internal WWAN antennas having multi-band operation capability and suitable to be embedded in smart phones are proposed in this thesis. In the industry, many customers require that the antenna radiation efficiency must achieve more than 40%, which become our target to design the antennas in this thesis. In the chapter 2, we proposed a quad-band antenna design by coupling a shorted parasitic element which control the input impedance effectively. The antenna might cover GSM850/900/1800/1900/UMTS operation. In the chapter 3, monopole antenna with a shorted parasitic element has been proposed. And the antenna is designed based on the concept of a quad-band antenna design that we just mention it. Moreover ,we improve the antenna bandwidth performance by coupling a monopole antenna. Finally, it can cover six bands, including LTE and WWAN GSM850/900/1800/1900/UMTS operation.
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Chen, Chang-Chih, and 陳長志. "Design of Multi-band Antennas." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/25675205837539735312.
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碩士<br>逢甲大學<br>通訊工程所<br>99<br>This study focuses on multi-band antennas mainly used for laptop and mobile phones. There are three antennas proposed in this research. The antennas were achieved by planar inverted-F antenna and monopole antenna.
The main operating frequencies of laptop antenna are at GPS(1.575 GHz), WLAN(2.4, 5.2 GHz) and WiMAX(2.5, 3.5, 5.5 GHz). The antenna has the advantages of simple structure, small size, easy fabrication, and easily integrated within thin laptop. The frequency at WiMAX band can be modified by adjusting a T-shaped monopole branch and stub. The antenna is fed by a coaxial cable. The area of the antenna is only 9×45.5 mm2.
Another antenna is used for mobile phone. The main operating frequency is at the 4th generation mobile communications LTE(704~787 MHz), GSM 900(880~960 MHz), GSM 1800(1850~1990 MHz) and WLAN(2400~2480 MHz). A coupling feed with a L-shaped microstrip line is used on the antenna. The L-shaped microstrip line is a path to excite 2.4 GHz high frequency mode. The antenna has a three-dimensional structure, and has an advantage of decreasing the total volume. The simulated and measured results have good agreement.
The other antenna is designed for six-band to cover LTE 700 (704 ~ 787 MHz), GSM 850/900 (824 ~ 960 MHz), DCS (1710 ~ 1880 MHz), GSM 1800 (1710 ~ 1880 MHz), PCS (1850 ~ 1990 MHz) and UMTS (1920 ~ 2170 MHz). A three-dimensional bending structure is used to miniaturize antenna size. Two branches are adding on the three-dimensional bending to achieve the required impedance bandwidth which is enough to cover the operating frequencies. The overall volume of the antenna is 6 × 10 × 45 mm3. It can be used in smart phone
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Jaramillo, Henao Carlos A. "Design and characterization of broad band and multi-band slot ring antennas /." 2004. http://grad.uprm.edu/tesis/jaramillohenao.pdf.
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Chuang, Min-Jie, and 莊閔傑. "Multi-Band CPW-Fed Slot Antennas." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/16056686850888024872.
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碩士<br>龍華科技大學<br>電子工程系碩士班<br>101<br>Multi-band CPW-fed slot antennas in IMT-2000 (1.92-2.17GHz), and in WLAN (2.4-2.4835 GHz/5.15-5.35GHz/5.725-5.852GHz), and in WiMAX(2.5-2.69 GHz /3.4-3.6 GHz) is proposed. The antenna consists of T-shaped signal strip, U-shaped conducting strip in the upper of T-shaped strip, and the ground slots. We design a dual-band T-shaped resonator antenna in 5.2GHz and 5.8GHz band. In addition, the U-shaped resonator is proposed to design in 2.4GHz band. This antenna is designed on single-layer PCB FR4 substrate with permittivity εr=4.4, loss tangent tanδ=0.0245, and thickness h=1.6mm. The antenna size of radiation area and ground plane is 50×50mm. A multi-band antenna is fabricated and measured to demonstrate the design. The results of measurements are in good agreement with the full-wave simulation results.
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peng, Chia-Mei, and 彭嘉美. "The investigation of multi-band small antennas." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/85125786448108430952.
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博士<br>國立臺灣科技大學<br>電子工程系<br>95<br>In this thesis, we present some concept that combine feeding network with imperfect ground-plane and printed antenna design to realize multi-frequency and wide-band antennas. The method to improve antenna impedance bandwidth is also analyzed and discussed.
The main research tasks are the development of antenna design concepts, implementation and measurements of small multi-band antennas. The “small antenna” here is defined as antenna’s ground structure that is smaller than antenna itself. The antenna design concepts are verified by experimental study.
The equivalent circuit of imperfect ground-plane of the printed circuit boards (PCBs) serves as the foundation to investigate the radiation mechanisms of small radiation elements. We then study the effect of imperfect ground plane on radiation impedance, bandwidth response, polarization and radiation patterns of printed antenna. Finally, five miniaturized, low profile printed antenna types were presented to verify the effect of imperfect ground-plane on the performance of printed antennas.
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Chang, Shu-Hao, and 張書豪. "Design of Multi-band Flat-Printing Antennas." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/6a6yax.
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碩士<br>輔仁大學<br>電機工程學系碩士在職專班<br>106<br>This research mainly studied the design of multi-band antennas to achieve the impedance match requirement of S11 ≤ 10 dB (VSWR ≤ 2dB). Both the simulated and experimental results are presented for the uniplanar multi-band antenna with optimized tuning performance in commercial wireless communications operating at 2.4GHz or from 5.15GHz to 5.825GHz. Three types of antenna designs are proposed in this study. The first antenna is a microstrip-line fed coplanar monopolar compound antenna with multiple slots, which are printed on a half-sided and double-triangle-shaped extension ground plane. The second antenna is a miniaturized monopolar compound multi-band antenna composed of a half-sided double-triangle-shaped antenna extension ground plane and an inverted-broom type of open-coupled microstrip antenna fed by a single coplanar-waveguide (CPWG) line. The third antenna is a forked microstrip monopolar compound multi-band antenna, in which the antenna extension ground plane consists of a pair of half-sided double triangle shaped metal surface and the radiator having the forked type of microstrip line. In this study, the antenna parameters of the three proposed novel designs are analyzed and optimized to meet our requirement, showing that the forked type of monopolar compound antenna can finally be optimized with good performance.
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Chen, Ting-Chung, and 陳鼎中. "Design of Ultra-Wideband and Multi-Band Antennas." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/61752079000049627162.
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碩士<br>國立中正大學<br>通訊工程研究所<br>95<br>Planar broadband slot antennas with elliptic, circular, rectangle shapes are investigated for multiband wireless communication. In order to reduce interference to WiFi system, the Ultra-Wide-Band elliptic slot antenna is further enhanced to have a 5~6 GHz notch band. The radiation patterns and averaged radiation gains are computed and measured. Finally, a meandered-line antenna based on mutually-coupled quarter-wavelength stubs are examined to have wide band radiation from 1.7~3.0 GHz for multi-standard GSM/DCS/PCS/WiFi/WiMAX application.
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Tsai, Hsin-chih, and 蔡欣致. "Design of Multi-band Rectangular Dielectric Resonator Antennas." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/xc3462.
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碩士<br>國立臺北科技大學<br>電腦與通訊研究所<br>100<br>In this thesis, the main of study is multi-band rectangular dielectric resonator antennas for multi-band applications. The dielectric resonator has many attractive features, such as high dielectric constant, high quality factor, low cost and low frequency temperature coefficient. Dielectric resonator can not only reduce the wavelength of resonance mode but also achieve antenna miniaturization. In this study, we proposed a multi-band dielectric resonator antenna operating at 1.85~3.7 GHz. The TE11δ and TE112+δ modes are excited in the proposed DRA through a rectangular slot on the ground plane. Then, using a CPW feeding structure was designed to excite high-order resonant modes. Multi-band operational characteristics are attainable through the three resonant modes within the dielectric resonator. Final, a hybrid structure DRA was designed with parasitic slot to increase 5.8 GHz band. DRA with multi-band operational characteristics are achieved through the design of two resonators.
The design of multi-band rectangular dielectric resonator antenna exhibited the impendence bandwidth which met the specification of PCS-1900(1850~1990 MHz), UMTS (1920~2170 MHz), WiMax-2.4(2300~2500 MHz), WLAN-802.11b(2400~2484 MHz), WLAN-802.11a(5150~5350/5.725~5.825 MHz) and WiMax-3.5(3400~3700 MHz).
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Luo, Pei-Chang, and 羅培彰. "Design of Printed Multi-Band and Diversity Antennas." Thesis, 2003. http://ndltd.ncl.edu.tw/handle/44944211827057937776.
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碩士<br>國立交通大學<br>電信工程系<br>91<br>In this thesis, some novel multi-band antenna is presented. The basic structure of the one of the presented antennas is a bent-folded monopole. Beside the natural dual-band performance of this antenna, we also add a metal piece to attaining to multi-band or wideband performance by producing another resonant frequency. Another multi-band antenna is a notch antenna. When we use the microstrip line to feed the slot line, the microstrip provides an approximate electric wall boundary condition for one mode to occur. We use this mode and the natural modes of slot antenna to complete multi-band antenna. Here we use HFSS (High Frequency Structure Simulation) to analysis the structure of the antennas.
In addition to we also propose a diversity antenna. According to the effects of these parasitic elements, we can decrease the mutual coupling effects of diversity antenna. All these antennas are designed for Bluetooth and IEEE802.11ab applications. Good agreement is obtained between simulation and experimental results.
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Wang, Mei-Hui, and 王美惠. "Design of Multi-band Antennas for Portable Devices." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/02140220698871920600.
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碩士<br>明志科技大學<br>電子工程系碩士班<br>103<br>The thesis proposes antennas of portable devices, including one dual-band monopole antenna applied to WLAN (Wireless Local Area Network) and Bluetooth, and the other multi-band slot antenna used in 2G, 3G, 4G mobile communications and GPS (Global Positioning System). The design of two antennas base on monopole antenna structure and can be realized on FR-4 PCB (Printed Circuit Board), which shows the merits of simple structures and easy to implement.
First, the dual-band monopole antenna is proposed in this paper, using two simple monopole structures, can comply applications both 2.4GHz and 5GHz band for ISM band (Industrial Scientific Medical Band, ISM Band), such as ZigBee, WLAN and Bluetooth. The size of antenna is 47 × 36.6 × 1.6 mm3. The antenna discloses a measured return loss greater than 10dB. For 2.4GHz band (2.4 ～ 2.48GHz), the peak gain is measured as -0.72dBi, and the radiation efficiency is more than 39.3%. For 5GHz band (5.15 ～ 5.875GHz), the peak gain is estimated at 3.23dBi, and the radiation efficiency is greater than 60.7%.
Finally, the multi-band slot antenna is planned by an inverted triangular monopole structure with coplanar waveguide feeding. Then, two slots are added to adjust resonance frequency and achieve characteristic of multi-band, which may cover the applications of GPS, GSM (Global System for Mobile Communications)850/900/1800/1900, UMTS (Universal Mobile Telecommunications System), LTE (Long Term Evolution)700/800/850/900 and LTE1700/1800/1900/2100/2600. The size of antenna is 120 × 50 × 1.6 mm3, and return loss is more than 6dB. For 0.8GHz band (0.7～0.96GHz), the peak gain is measured as -0.3dBi, and the radiation efficiency is greater than 25.2%. For 1.9GHz band (1.7～2.17GHz), the peak gain is measured as 3.9dBi, and the radiation efficiency is greater than 52.5%. For 2.6GHz band (2.56～2.7GHz), the peak gain is measured as 3dBi, and the radiation efficiency is greater than 44.8%.
Two antennas are proposed and contained in this thesis for portable device applications of nowadays, including mobile phone communications, GPS, Wi-Fi and Bluetooth. The sizes of two proposed antennas are suitable for portable devices. The measured characteristics of proposed antennas are good enough to meet the actual needs of the industry.
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Mo, Chia-Yang, and 墨家揚. "Dual-Port Multi-Band Antennas for Wireless Communications." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/77577017678243682501.
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碩士<br>長庚大學<br>電子工程研究所<br>95<br>This thesis presents two designs of dual-port tri-band antennas which cover 802.11a/b/g and WiMAX at the same time. The first one is built by evacuating the center part of a slot antenna and inserting another one into the blanked area to form a tri-band antenna with separate input ports for IEEE 802.11a/b/g and WiMAX operation. Meanwhile, by inserting embedded lumped elements and shorted slot metal, good impendence match and size reduction are achieved simultaneously. The antennas are fabricated on an FR4 PCB with a size of only 28.2 × 21.4 mm2. The isolation between the two antennas is better than 11 dB. Peak gains at lower, middle and upper bands are of 0.8, 2.9 and 3.4 dBi, respectively. Omnidirectional radiation patterns and good in-band gain are also achieved.
The second one is built by integrating a planar inverted-F antenna and a slot line antenna to form a tri-band antenna with separate input ports for IEEE 802.11a/b/g and WiMAX operation. Moreover, good impendence match and compact size are obtained by meandering each radiating element of the antenna and inserting capacitive or inductive lump elements. The antennas are fabricated on an FR4 PCB with a size of only 20 × 21.5 mm2. The isolation between the two antennas is better than 11 dB. Peak gains at lower, middle and upper bands are of 1.8, 6.8 and 3.7 dBi, respectively. Omnidirectional radiation patterns and good in-band gain are also achieved.
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Yang, Min-Hsin, and 楊旻鑫. "Investigation of MIMO, PIFA and Multi-band Antennas." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/17033649637300693084.
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碩士<br>國立中正大學<br>電機工程研究所<br>99<br>This paper is divided into three parts. The first part is MIMO antennas design. By using the added resonator into two antennas, the extra transmission zero can be generated and the isolation within the MIMO antenna can be increased. Moreover, the resonant central frequency and transmission zero can be tuned by properly control the circuit parameters. Furthermore, the electromagnetic simulator is utilized to predict the result.
The second part is the multi-band antenna design. This antenna with multiple bands can be produced by using multiple current loops. We can adjust the circuit parameters to control the band of antenna. The third part is PIFA antenna. The advantages of PIFA antenna are easily design and impendence match. In this part, two operating bands of antenna can be controlled with separate parameters, and the electromagnetic simulator is adopted as assistance.
All of antennas in this thesis are simulated with full-wave electromagnetic simulator, and the circuits are then fabricated and measurement. The results of good match between the simulation and measurement show the availability of all proposed circuits.
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Shih, Shao-Yun, and 施卲昀. "Design of Multi-band Antennas for Mobile Devices." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/69399421199275473434.
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Chang, Yu-Hsiang, and 張宇翔. "Design and Modeling of Multi-band Notched Antennas." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/90793933560244660583.
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碩士<br>國立臺灣大學<br>電信工程學研究所<br>101<br>In this thesis, a multi-band MIMO antenna system is proposed. Compared to the traditional multi-band antennas using extended geometry to obtain additional operation bands, we employed the band-notching concept to achieve multi-band operation. We started with the analysis of the microstrip line over a V-shaped defected ground structure. Then, we applied V-slots on the UWB monopole antenna. By properly designing the slot dimension, we can notch out unwanted bands to complete a multi-band antenna. Using the proposed design method, the antenna can be easily modified for various applications simply by re-designing the V-slots without changing the antenna dimension. The mutual coupling is a critical issue when two antennas are closely spaced. We also applied the band-notched slots on the common ground. The isolation of two antennas was successfully enhanced.
The equivalent circuit models of V-shaped DGS, UWB monopole and tri-band notched antenna are proposed. Through the circuit model, we have a deeper insight of the working principle of our designs. The prototype of UWB monopole antenna, tri-band notched antenna and multi-band MIMO antenna system were designed, built, and tested with a very good agreement between the simulated and measured results.
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Chuang, Kai-Jen, and 莊凱任. "Multi Band Antennas Designs For Slim Notebook Applications." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/cphz6a.
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碩士<br>國防大學理工學院<br>電子工程碩士班<br>102<br>In this thesis,three type of small-size ultrabook computer antennas design are presented. The first antenna designed for WLAN MIMO array antenna with high isolation and good radiation has a small size of 45 × 6 mm2. An isolation element formed by two quarter-wavelength slots have been shown to effectively enhance the isolation between the antennas in this study. The second antenna can provide LTE/WWAN eight-band operation without any additional antenna dimensions. By using the ground plane area nearby the hinge as the radiator and designing a switching circuit to select an appropriate feeding position, the wide operating band can be easily achieved. The third antenna can provide DTV/LTE700/WWAN operation. By using the display and keyboard grounds as the radiators, the good radiation characteristics and wide operating band can be easily achieved.
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Yang, Jiin-Hwa, and 楊錦華. "Design of Multi-band Antennas for Mobile Device Applications." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/e43r5z.
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博士<br>逢甲大學<br>電機與通訊工程博士學位學程<br>105<br>Four types of multi-band antennas for mobile device applications are designed and proposed in this research. The antenna structures are implemented by planar inverted-L monopole, T-shaped monopole and radiation branch. The first, a compact multiband internal antenna for LTE/WWAN mobile phone application is presented. The structure of proposed antenna is composed of a coupling feed L-shaped monopole and a grounded meandered branch. The antenna occupies a small volume of 14×45×4 mm3. The coupling feed L-shaped monopole excites a widely operating band to cover the frequency range of 1750~2525 MHz for DCS/PCS/UMTS/LTE/WLAN operation. The grounded meandered branch excites low frequency operation band to cover the frequency range of 675~985 MHz for the LTE700/GSM850/GSM900 operation.
Secondly, a compact multiband antenna for LTE/WWAN handset applications is proposed, which comprises an inverted-L shaped feeding monopole and two folded shorting strips. A three-dimensional bending structure is designed to minimize the size antenna which makes the antenna only with a volume of 13×45×5 mm3. This antenna operates over nine bands, including LTE700/2300/2500, GSM850/900/1800/1900, UMTS2100 and WLAN2400.
The third, a frequency reconfigurable antenna suitable for handset applications is proposed. The antenna structure includes an inverted-L shaped monopole and two meandered shorting strips. To minimize the antenna size, a three-dimensional bending structure with a PIN switch diode is designed to implement the property of reconfigurable frequency. The antenna’s volume is 9×50×5 mm3, and it covers operation bands of LTE700/2300/2500, GSM850/900/1800/1900, UMTS2100, and WLAN2400.
Finally, a compact printed multi-band antenna for laptop applications is proposed. The antenna structure is composed of T-shaped monopole and grounded inverted L-shaped branch. It occupies a small area of 9 × 47 mm2 and has the advantages of simple structure, small size, easy fabrication, and integration within thin laptop. The main operating frequencies are at GPS (1.575 GHz), WLAN (2.4, 5.8 GHz), Bluetooth (2.45 GHz) and WiMAX (2.5, 3.5, 5.5 GHz) bands.
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Chih-KuangWu and 吳智光. "Design of Multi-Band Antennas for Implantable Biotelemetry Applications." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/92135357758104932394.
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博士<br>國立成功大學<br>電機工程學系碩博士班<br>101<br>This dissertation presents the design of a novel multi-band antenna for implantable biotelemetry applications. In the previous literatures, most of the reported implantable antennas were designed for applying in single, dual, or triple frequency bands. Beside, these published antennas had the disadvantages of large volume, narrow bandwidth, low gain, and insufficient application bands. To meet the multiple purposes of the bio-telemetry applications in the future, the implantable antennas need to provide the functions of physiology information transmission, wireless powering, micro pump controlling, and system wake-up. In this dissertation, an implantable antenna with four application bands, compact size, and good performances is proposed for employing in Body Area Networks (BAN) below 3 GHz. The four application bands are Medical Device Radiocommunications Service band (MedRadio) (401-406 MHz), Wireless Medical Telemetry Service band (WMTS) (1427-1432 MHz), and two industrial, scientific, and medical bands (ISM) (433-434 MHz and 2.4-2.4835 GHz).
For achieving the miniaturization and broadband of the implantable antenna, the methods used in this study consist of (1) tuning fringe field capacitance effects to improve bandwidth; (2) changing probe feed position to increase impedance matching; (3) using three-layer stacked planar inverted F antenna (PIFA) to accomplish the goals of miniaturized volume and multi-band operation.
First, the feasibility of a capsule endoscope antenna operates in mimicking stomach at the MedRadio band is implemented and verified. Second, the implantable antenna uses fringe field capacitance effect to design and verify its characteristics of wideband and miniaturization at the MedRadio band. Meanwhile, this proposed antenna directly matched to a low power RFIC without RF matching network is verified by simulation. Third, the proposed implantable antenna applying in ZigBee dual band (900 MHz and 2.4 GHz) system is also verified. After confirming the functions of the three proposed antennas mentioned above, the final structure of the proposed design is constructed on a three-layer substrate including a PIFA antenna with an S-shaped radiated element and two stacked twin spiral stripes. The proposed design uses a shorting pin to connect layer 1 and layer 2, which lengthens the effective current path of the two primary resonances. After properly controlled the two primary resonances and their higher modes, the broad bandwidth and quad-band are obtained. By searching the existed designs, the proposed antenna is the only one that can operate in four operation bands, reduce 30 % in volume, provide 160 % wider bandwidth, and increase 140 % in gain. According to the advantages listed above, the proposed quad-band implantable antenna can easily be combined and applied with the biotelemetry systems.
To verify the radiated efficiency of proposed antennas, this dissertation sets up the antenna in an open environment with various kinds of RF interferences for practical measurements. The received power of the proposed antenna is measured through network analyzer, RF signal generator, spectrum analyzer, and ZigBee evaluation kit. According to the measured results, the proposed antennas present suitable performances and can be applied in implantable biotelemetry systems.
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Lai, Yen-Ru, and 賴彥儒. "Design of Internal Multi-Band Antennas for Mobile Handsets." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/43802347620362983831.
Full textAbstract:
碩士<br>大葉大學<br>電機工程學系<br>98<br>This thesis aims at designing internal antennas that can be used in mobile handsets. Two antennas have been designed, both being able to support the five commercial communication standards: GSM850, GSM900, DCS1800, PCS1900, and UMTS2000. One of the antennas can support an additional 2.4-GHz WLAN band, and the other an additional 1.57-GHz GPS L1 band. In other words, both antennas are hexa-banded.
These antennas are designed using several electric monopole and dipole structures to obtain the required operating frequency bands. They are fabricated on commercially cheap FR4 substrates. Low cost, compactness, lightweight, and easy fabrication are the main advantages of these antennas.
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Lin, Chih-Rong, and 林志榮. "Design and Measurement Techniques of Multi-Band Small Antennas." Thesis, 2003. http://ndltd.ncl.edu.tw/handle/40329832835485603553.
Full textAbstract:
碩士<br>國立交通大學<br>電信工程系<br>91<br>The designs of multi-band and small antennas are widely proposed in national/international microwave conferences and academic journals. And integrating the two mention advantages is in great demand for current research and commercial products. In this thesis, the proposed multi-band antennas successfully implement 3-D whipping structure with Low Temperature Cofired Ceramics (LTCC) and multi-layer printed circuit board to achieve small dimension and hold out the primary performance effectively. And then, summarize and discuss some conclusions with respect to measurement techniques of small antennas for verify its characteristics.
The structures of antennas presented in this thesis are extended types of l/4 monopole. Bending the antenna body and the properties of multi-layer board so that we can minimize the profile and reduces the cost. In this work, Ansoft HFSS is used to be the design tool, and analyze the proposed antenna with lumped element circuit models. After testing and measuring the specifications of the antennas, we expect to acquire more information of the antennas operation principles through the discussions of circuit models.
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Ho, Wen-Pin, and 何文彬. "Design of Multi-Band Antennas For Wireless Communication System." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/85334455254902181824.
Full textAbstract:
碩士<br>逢甲大學<br>電機工程所<br>99<br>In this thesis, the designs of multiband antennas for wireless communication system are studied. Here, three different antennas structure for mobile application are investigated and discussed. A hybrid mobile device antenna with double-layer structure for multiband operation is initially proposed. It is able to cover the wireless applications such as GSM/DCS/DCS/UMTS/WLAN 2400. The main structure of this antenna is composed of two layers; the top layer of proposed antenna produces three resonance modes (at around 0.88, 0.97 and 1.18 GHz) with respect to three radiation strips. The bottom layer of proposed antenna produces three resonance modes (at around 1.38, 1.76 and 2.45 GHz) by embedding a T-shape open-ended slot into the rectangle radiation patch. The second proposed antenna is a compact size (15 mm × 40 mm) microstrip-fed printed planar inverted-F antenna (PIFA) for mobile applications. The main structure of this antenna is a simple double-folded PIFA with two wide open-ended radiating sections. By tuning the two wide open-ended radiating sections, optimum impedance matching and inclusion of UMTS band can be achieved. Compared to the previously proposed antenna, this antenna has the advantages such as planar structure, and additional operating band in the WLAN 5.2/5.8 and WiMAX. Finally, a coplanar printed antenna with inverted L-shape coupling feed is proposed. By using an inverted L-shape coupling feed and a meandered shorting strip, two wide operation bands are excited. Both the lower and upper operation band can cover LTE 700/GSM and DCS 1800/PCS 1900/UMTS/LTE 2300, respectively. To operate at LTE 2500 band, a technique of joining a parasitic stub around the feed point which excites a resonance mode at 2.72 GHz is introduced. This proposed antenna can be used as a multiband antenna operation for the application in fourth generation (4 G) wireless communication system. By comparing to the other wireless communication system, the 4G wireless system can provide faster transmission speed and more system capacity.
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Hung-ChiChang and 張竑琦. "Embedded Multi-Band Antennas for Portable Navigation Device Application." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/25817071801426523128.
Full textAbstract:
碩士<br>國立成功大學<br>電機工程學系專班<br>98<br>In this thesis, the design mainly focuses on the portable navigation device (PND) of signal receiving multi-band antenna, which is embedded into PND. In the industry, many customers require that the antenna radiation efficiency must achieve more than 40%, which become our target to develop GSM/GPRS antennas in this thesis. Three kinds of GSM/GPRS antennas design are presented and discussed in our studies. These antennas can cover GSM900/DCS/PCS/UMTS operation. In the chapter 2, the antenna is designed based on the concept of monopole antenna. Furthermore, the antenna structure have two radiant paths and coupled each other at tail end to do impedance matching. In addition, to raise distance between radiation plane and ground will avoid capacitative effect effectually. In the chapter 3, the antenna is designed based on the concept of planar inverted-F antenna. Furthermore, that the antenna structure have two radiant paths and coupled each other at tail end to do impedance matching is similar to chapter 2. But there is a difference in them. We can choose the short position to change input impedance at this structure. In the chapter 4, the antenna is designed based on the concept of planar inverted-F antenna which takes coupled-fed. It will produce the first mode and high-order mode near the frequency, 900MHz. The feature of this type is to reduce the volume effectually. This antenna can not only cover GSM900/DCS/PCS/UMTS operation but maintain good radiation efficiency. Finally, we will compare three antennas, and develop procedure with industrial view, and propose the prospect of the GSM/GPRS antenna in PND, as a conclusion.
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Chen, You-Chieh, and 陳祐傑. "Multi-band slot dipole antennas fed by coplanar waveguide." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/11800959700747925313.
Full textAbstract:
博士<br>國立臺灣大學<br>電信工程學研究所<br>99<br>Several dual- or multi-band slot dipole antennas fed by CPW for wireless communication systems are proposed in this dissertation. First of all, the effect of parasitic slots on the radiation patterns of the first harmonic mode of a coplanar waveguide-fed slot dipole antenna is presented. By adding four parasitic slots, the radiation patterns of the first harmonic mode of the slot dipole can be modified to be similar to those of its fundamental mode. Therefore, this antenna would operate as a dual-band operator with similar radiation patterns.
Secondly, a aperture-coupled slot dipole antenna capable of tri-band operation is proposed. The lower and middle bands can be obtained by varying the lengths of the lower and middle pairs of the protruded slots, respectively, while the upper frequency can be determined by adjusting the lengths of the upper protruded slot pair and the coupling aperture pair.
Thirdly, a compact bow-tie slot antenna capable of tri-band operation is proposed. Unlike most of other multi-frequency antennas having their sizes determined by the lower resonant frequency, the size of the proposed antenna is determined by the upper resonant frequency and thus it is compact in nature. The middle and lower operating frequencies are obtained by inserting two metal strip pairs near the ends of the bow-tie slot without increasing the overall antenna area.
Finally, a dual-band slot dipole antenna capacitively fed by a CPW is proposed. By adding a pair of slot stubs into the extended CPW signal strip, the resonant frequency of second harmonic mode of the slot dipole can be perturbed and reduced without increasing the antenna area while the performances of the fundamental mode are retained. This antenna is compact when compared with other CPW-fed inductively-fed slot dipole antennas.
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LIU, HENG-YU, and 劉恒佑. "Multi-band Array Antennas Design for 5G NR Applications." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/knqe8h.
Full textAbstract:
碩士<br>逢甲大學<br>電機工程學系<br>106<br>In this thesis, two multi-band eight-antenna array designs (antenna-A and antenna-B) are presented. The two proposed antennas are suitable for future fifth-generation smart phone applications, and their operating bands apply not only to Band-n77 (3.3–4.2 GHz) and Band-n79 (4.4–5 GHz) proposed in the fifth generation new radio (5G NR), but also to the unlicensed international information infrastructure (U-NII) band (5.15–5.925 GHz) and unlicensed 6-GHz band (5.925–7.125 GHz).
The array element of the proposed antenna-A is a gap-coupled loop antenna with an inverted-L open slot. A 3.46 GHz mode is excited by the gap-coupled loop structure that can partially cover the 5G band in China (3.3–3.6 GHz) and the European 5G band (3.4–3.8 GHz). Here, the inverted-L open slot excites a 4.85 GHz mode to partially cover the 5G band in China (4.8–5 GHz), while the monopole structure excites multiple resonance modes to cover the unlicensed 6-GHz band that is still under discussion in the United States. The measured efficiency of each array element was higher than 40%, and the measured isolation and envelope correlation coefficient (ECC) between adjacent array elements were lower than -10-dB and 0.3, respectively. According to the calculation results of the channel capacity, when the proposed antenna-A is applied to an 8×8 multi-input multi-output (MIMO) system, the minimum total channel capacity (with applicable operating bandwidth) can reach up to 69.1 Gbps.
This thesis has also proposes another antenna array design, and it is now known as proposed antenna-B. The array element of proposed antenna-B is an inverted-F antenna with shorting branches and parasitic elements. The driving element (monopole structure) and the shorting element (inverted-L branch and inverted-C branch) enable the antenna to obtain multiple modes, and the parasitic element, open slit, and stub can improve the impedance matching. Compared with the proposed antenna-A, the 6-dB impedance bandwidth of proposed antenna-B can completely cover the 5G band of US (3.55–4.2 GHz), China, EU and Japan(3.6–4.2 GHz, 4.4–4.9 GHz), as well as the LTE Band-46 (5.15–5.925 GHz) extended by U-NII. The measured efficiency of each array element was higher than 40%, the measured isolation between adjacent array elements was lower than -10-dB, and the ECC was also lower than 0.3. From the calculation result of the channel capacity, when the antenna-B is applied to an 8×8 MIMO system, the total channel capacity (with applicable operating bandwidth) can reach up to 79.6 Gbps.
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Hsiao, Jia-Hung, and 蕭家宏. "Development of Miniaturization Flexible Printed and Multi-Band Antennas." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/mzsp5j.
Full textAbstract:
碩士<br>國立臺北科技大學<br>機電整合研究所<br>96<br>The design of miniaturized antennas will become a future trend as customers are pursuing consumer electronics and communication products towards lighter, thinner, shorter and smaller.
This thesis aims to develop a miniaturized FPC antenna with features of small dimension, low-power consumption, much thinner, low cost, and it is particularly best for a sufficient transmission range and little space installation. As a result, we attempt to design a novel antenna by combining Hilbert fractal with Inverted-F structures to increase the efficiency of this specially designed miniaturized antenna. Inverted-F antenna, in essence, is characterized by miniaturization, and its other characteristics such as working bandwidth, size and gain could be further boosted as connected with the Hilbert fractal structures to make the main structure of the antenna.
We investigate the FPC antenna by focusing on the 2.4-GHz ISM band. The measuring results are 2.46 GHz in center frequency and -22.3 dB in return loss, respectively. As the return loss less than -10 dB, the measuring results of the antenna are 180 MHz (2.37~2.55 GHz) in bandwidth, 7.3% in bandwidth percent, and 1.46 dBi in peak gain, respectively.
The other design in this thesis is a miniaturized multi-band antenna. The antenna is proposed for applications in RFID band (922~928 MHz) that Taiwan open up to use and WLAN applications in IEEE 802.11 a/b/g (2.4~2.4835 GHz、5.15~5.35 GHz、5.470~5.725 GHz、5.725~5.825 GHz).
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Hsu, Sheng-Hsiung, and 許勝雄. "Design and Analysis of Multi-band Mobile Phone Antenna and 13.56 MHz NFC Antennas." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/95441877411781438566.
Full textAbstract:
碩士<br>義守大學<br>電機工程學系碩士班<br>98<br>A variety of internal mobile phone antennas with a multiband antenna and 13.56MHz antenna are proposed. The antennas ate suitable to be embedded in the mobile communication device. At first. The first antenna is comprised of a loop antenna and a monopole antenna for DCS (1710 ─ 1880 MHz), PCS (1850 ─1990 MHz), WCDMA/ HSPDA (1920 ─ 1980MHz), UMTS (1920 ─ 2170 MHz) and WiMAX (2500 ─ 2690/3400 ─ 3600 MHz) applications. Design of a multi-band antenna and a system ground plane In the same direction. So that the proposed antenna is comprised of a multi-band antenna and a 13.56MHz antenna. And the proposed antenna for NFC, DCS, PCS, WCDMA/HSPDA, UMTS and WiMAX applications.
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鄭力元. "Design of Novel Multi-Band Printed Dipole Antennas and Miniaturized Printed Folded Dipole Antennas." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/49105943661162720962.
Full textAbstract:
碩士<br>國立交通大學<br>電信工程系所<br>97<br>Multi-band printed dipole antennas with brand-new structure are presented in first part of this thesis. Unlike traditional dipole antenna fed from the center, a printed dipole antenna integrated with modified microstrip ring hybrid can realize a novel model of dipole antenna which is fed from end to end. Because the phase difference and magnitude ratio of signals from two output ports of microstrip ring hybrid vary from frequency to frequency, balanced and unbalanced signals will be produced to form different resonant mode and relative effective radiaton path. Furthermore, there is more then 80% -10dB return loss bandwidth in input signal of microstrip ring hybrid. This thesis combines above aspects with sophisticated integration and design to achieves a target of multi-band and wideband operation of printed dipole antenna successfully.
A new method of antenna miniaturization is presented in second part of this thesis. Adding symmetric annular parasitic conductor of appropriate shape and size to folded dipole, image current will be induced in annular parasitic conductor while the total radiation length will be increased. Moreover, annular parasitic conductor with induced current working as loop antenna will be resonated to radiate and provide its resistance in series with folded dipole simultaneously. Among above process, the inductive reactance will be produced by the structure carrying closed current loop to compensate capacitive dipole antenna at lower frequency, and it eventually attains the objective of bringing about large amount of drop in resonant frequency of proposed antenna successfully. The design of 1.4GHz printed folded dipole antenna with one side meandering is taken as elementary antenna. After integrating elementary antenna with annular parasitic conductor, the resonant frequency can drop from 1.4GHz to 0.87GHz, and the good radiation property still be maintained. The effect of annular parasitic conductor toward printed folded dipole antenna and the physical mechanism and principle which cause frequency drop will be further discussed in our research of this thesis.
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Cheng, Po-Chun, and 鄭博鈞. "Design of Multi-Band Planar Antennas for Mobile Handset Applications." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/59822559949995820154.
Full textAbstract:
碩士<br>國立彰化師範大學<br>電信工程研究所<br>98<br>In this thesis, mobile phone antennas design using microstrip-fed and CPW-fed were studied. Three different mobile phone antenna structures were designed, implemented, and investigated. An internal multiband CPW-fed monopole antenna designed for mobile handset applications is first proposed. By embedding an open-ended slot and two parallel slits into the ground plane and radiating element, respectively, a triple-band operation measured along VSWR 3 : 1 that is able to cover the wireless applications such as GSM, DCS, PCS, UMTS, WLAN, and WiMAX can be achieved for this antenna.
The second proposed antenna is a compact size planar microstrip-fed monopole antenna designed for mobile handset applications. To operate at GSM/GPS/DCS/PCS/UMTS and WLAN bands, a hybrid technique of joining the horizontal section of a T-monopole to an open-loop back coupling strip and loading a pair of monopole slots into the ground plane is employed. Two operating bands are observed (along 3:1 VSWR) with the lower band covering only the GSM application, while the wide upper operating band covers the remaining applications. Finally, we proposed a printed compact planar inverted-F antenna (PIFA) with a folded design for mobile handset operating within the GSM/PCS/DCS band. To additionally cover the wireless local-area network (WLAN) frequency spectrum at 2.4 GHz, a narrow stub is protruded from the printed shorting wall. The excitation of these operating bands with desirable bandwidth is achieved by feeding a 50-ohm microstrip line to the folded radiating element through a via hole.
The effects on all the proposed antennas and their corresponding performances by tuning the various vital parameters have been studied. The approaches and antennas presented in this thesis are expected to serve as useful references for the researchers and engineers working in this area.
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Huang, Guo-Lun, and 黃國崙. "Design of Multi-Band Planar Antennas for WLAN/WiMAX Applications." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/23742508864341916208.
Full textAbstract:
碩士<br>國立臺灣海洋大學<br>電機工程學系<br>97<br>In this thesis, several designs of compact multi-band planar antennas fed by CPW line for WiMAX applications are presented and experimentally studied. The study of a multi-band planar monopole antenna embedded with an I-shaped slot and an I-shaped parasitic metal plate has been firstly presented. The proposed antenna can excite a new resonant mode close to the fundamental mode due to the asymmetrical I-shaped parasitic metal plate to cover the WLAN 2.4 GHz. Next, a wideband monopole antenna with two strips and a pair of notches is proposed. The first resonant mode is excited due to the longer strip with the second resonant mode due to the shorter strip. By adjusting the dimensions of the notches, the proposed monopole antenna can have good impedance matching to achieve wideband operation with the combination of multi-resonant modes. Finally, design of a compact slot antenna is presented by using dual U-shaped slots to excite the first and second resonant modes with the higher mode excited by the L-shaped strip as the monopole antenna. By properly choosing the depth of the U-shaped slot, the antenna bandwidth can be enhanced across the 2.5/3.5/5.5 GHz WiMAX bands and 5.2/5.8 GHz WLAN bands.
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Jhuang, Jheng-Bing, and 莊政屏. "Design of Multi-band Microstrip Antennas by using Parasitic Elements." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/nnmju8.
Full textAbstract:
碩士<br>國立臺灣海洋大學<br>電機工程學系<br>105<br>This work presents an applied research and design of antenna suitable for a Wireless Local Area Network (WLAN) IEEE 802.11a / b / g (2.45GHz, 5.15GHz, 5.75GHz) base station. The designed antenna should have multiband capability and directional radiation ability so that it may overcome the many factors that may contribute to signal degradation due to atmospheric absorptions and scattering.
First, we used a 1.6 mm thick glass fiberboard (FR4) to design a rectangular microstrip antenna resonating at TM_10 mode with a frequency of 2.45GHz. The second step involved the modification of the length and width of the rectangular patch microstrip antenna to obtain a dual band antenna. The long side of the rectangular patch is tuned to resonate at 2.45 GHz and the short side resonating at 5.15 GHz, corresponding respectively to the TM_01 and TM_10 mode of the new dual band antenna.
Finally, a multi-band rectangular microstrip antenna is designed by adding parasitic metal components on the long side of the rectangular patch. The multi-band are resonating at 2.45GHz, 5.15GHz and 5.75GHz, corresponding respectively to TM_10, TM_20, and TM_11 mode of the newly designed resonator. For the fabricated multi-band antenna, our measurements showed reflection loss less than -10 dB for the triple band, namely, -19.25 dB at 2.45 GHz, -19.55 dB at 5.15 GHz, and -18.33 dB at 5.75 GHz. The measured data agreed well with our simulated results showing the good design consideration of our work.
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Chu, Yi-Chung, and 朱繹中. "Multi Band and MIMO Antennas Designs For Laptop Computer Applications." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/df4qh8.
Full textAbstract:
碩士<br>國防大學理工學院<br>電子工程碩士班<br>102<br>This thesis presents two small-size antennas and one MIMO antenna for laptop-computer applications. The first antenna designed for operating at the LTE/WWAN bands has a small size of 50×10 mm2. The bandwidth-enhancement technique is mainly employing by a pair of printed parallel strips which is equivalent to a parallel-resonant circuit. The second antenna designed at the same operating bands has a smaller size of only 40 × 10 mm2 than the first one. The size-reduction design idea is implemented by using a reconfigurable circuit element embedded in a gap between metal strips. Finally, a design technique to improve the isolation for MIMO antenna system is also presented. With the isolation-enhancement technique of adding a pair of isolation elements on the supporting metal plate of the laptop computer, the isolation can effectively be improved at LTE 700 band for MIMO operation.
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Lee, Yun-Tsan, and 李昀燦. "Embedded Multi Band Antennas Designs for Slim Laptop Computer Applications." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/fpt6e9.
Full textAbstract:
碩士<br>國防大學理工學院<br>光電工程碩士班<br>103<br>This thesis presents two small-size antennas and one LTE MIMO antenna for ultrabook computer applications. The first antenna designed for operating in the LTE/WWAN seven-band has an embedded small-size of 40 × 8 mm2. The antenna structure is a simple hook-shaped strip. By using the surrounding ground plane around the antenna as the resonance path to reduce the antenna’s size. The hook-shaped strip can also excite the hinge slot and open slot placing the antenna element simultaneously to wide the operating band. The second antenna can provide LTE/WWAN eight-band operation without any additional antenna dimensions. The antenna comprises a hook-shaped strip and a shorted stripe to form the coupled-fed loop. By increasing the length of the shorted stripe to lower the resonance frequency in lower band to cover LTE/WWAN eight-band operation. The third LTE MIMO antenna with high isolation and good radiation can effectively enhance the isolation between the antennas by designing an open slot as an isolation element. The open slot can effectively enhance the isolation between the antennas with a small size of 80 × 5 mm2.