Dissertations / Theses: 'Monopolar antenna'

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Schlub, Robert Walter, and n/a. "Practical Realization of Switched and Adaptive Parasitic Monopole Radiating Structures." Griffith University. School of Microelectronic Engineering, 2004. http://www4.gu.edu.au:8080/adt-root/public/adt-QGU20040610.112148.

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Switched and adaptive parasitic monopole array radiating structures are investigated. Antenna design is orientated toward increasing practicability for implementation in terrestrial wireless communication systems. A number of antennas are designed with the aid of optimization and commercial simulation software. Simulation procedure was verified with the experimental manufacture and measurement of the arrays. The antennas presented in this thesis comprise an active monopole surrounded by a ring of parasitic monopoles. Parasitic radiators are constructed with static loading to enable simple experimental realization. Beam positions of an electrically steered equivalent antenna are thus simulated. Antenna symmetry ensures the beam can be reproduced throughout the azimuth. Complex antenna geometries require antenna design through optimization. A genetic algorithm is employed with HFSS and NEC for electromagnetic analysis. The robust optimization method couples with simulation software flexibility to provide an effective design tool for arbitrary structures. The genetic algorithm is employed strictly for design and not complete structural optimization. Dual band, five and six element switched parasitic antennas are presented. Lumped elemental loading along the radiators provide resonance and directed radiation at two GSM frequencies. Load value, radiator dimension and spacing are incorporated as design parameters. Experimentally built, 10dB return loss bandwidths of 17.2% and 9.6% and front to back ratios of 12.6dB and 8.4dB at 900MHz and 1900MHz respectively are measured. To reduce the ground requirements of monopole arrays, a skirted ground structure for switched parasitic antennas is analyzed. A six element switched parasitic monopole array with conductive ground skirt exhibits a front to back ratio of 10.7dB and main lobe gain of 6.4dBi at 1.575GHz. Radiation is not elevated despite lateral ground terminating at the parasitic elements. Skirt height is observed to linearly control radiation elevation, depressing the principal lobe through 40 degrees from 23 degrees above the horizontal. The Electronically Steerable Passive Array Radiator or ESPAR antenna is an adaptive parasitic monopole array. An ESPAR radiating structure incorporating a conductive ground skirt is designed for operation at 2.4GHz. Utility is confirmed with a frequency sensitivity analysis showing consistent electrical characteristics over an 8.1% bandwidth. The antenna design is improved with optimization to reduce average principal lobe elevation from 25 degrees to 9.7 degrees.

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Kabalan, Aladdin. "Miniaturisation et modélisation d’antennes monopoles larges bandes utilisant des matériaux magnéto-diélectriques en bande VHF." Thesis, Rennes 1, 2019. http://www.theses.fr/2019REN1S041/document.

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Les avions comportent plusieurs systèmes de navigation et de communication nécessitent des antennes VHF large bande. Réduire la taille de ses antennes est un enjeu majeur tout en gardant des bonnes performances. Cette thèse propose des nouvelles configurations d'antennes à profil bas utilisant des nouveaux matériaux nanocomposites non conducteurs constitués de nanoparticules magnétiques développés au Lab-STICC. Un monopole planaire large bande a été développé et optimisé avec un taux de miniaturisation de 60% grâce à l'utilisation d'un matériau magnéto-diélectrique de forte perméabilité et faible pertes couvrant seulement 5% de sa surface. Les résultats expérimentaux, en presque parfait accord avec les simulations, montrent que le diagramme de rayonnement est omnidirectionnel et que la polarisation est verticale, avec un bon niveau du gain. L'antenne monopole planaire insérée dans un MMD des dimensions limitées avec des pertes a été modélisée par un nouveau circuit équivalent multi résonant. Ce circuit est développé à partir de l'impédance d'entrée de l'antenne et des caractéristiques du MMD, et validé par les simulations avec un parfait accord entre les résultats
Airplanes with multiple navigation and communication systems require broadband VHF antennas. Reduce the size of these antennas is a major challenge while keeping good performances. This thesis proposes new configurations of low profile antennas using new nanocomposite non-conductive materials consisting of magnetic nanoparticles developed at Lab-STICC. A broadband planar monopole has been developed and optimized with a 60% miniaturization rate thanks to the use of a high permeability and low loss magneto-dielectric material covering only 5% of its surface. The experimental results, in almost perfect agreement with the simulations, show that the radiation pattern is omnidirectional and that the polarization is vertical, with a good level of gain. The planar monopole antenna inserted in a MMD of limited dimensions with losses was modeled by a new multi-resonant equivalent circuit. This circuit is developed from the input impedance of the antenna and the characteristics of the MMD. and validated by the simulations with a perfect agreement between the results

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Morsy, Mohamed Mostafa. "DESIGN AND IMPLEMENTATION OF MICROSTRIP MONOPOLE AND DIELECTRIC RESONATOR ANTENNAS FOR ULTRA WIDEBAND APPLICATIONS." OpenSIUC, 2010. https://opensiuc.lib.siu.edu/dissertations/169.

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Ultra wide-band (UWB) technology is considered one of the very promising wireless technologies in the new millennium. This increases the demand on designing UWB antennas that meet the requirements of different UWB systems. In this dissertation, different UWB antennas are proposed such as an antenna that covers almost the entire UWB bandwidth, 3.5-11 GHz, as defined by the federal communication commission (FCC). This antenna has a size of 50×40×1.5mm3. Miniaturized worldwide UWB antennas are also introduced. Miniaturized worldwide UWB antennas that have compact sizes of (30×20×1.5) mm3, and (15×15×1.5) mm3 are also investigated. The designed worldwide UWB antennas cover the UWB spectrums defined by the electronic communication committee (ECC), 6-8.5 GHz, and the common worldwide UWB spectrum, 7.4-9 GHz. A system consisting of two identical antennas (transmitter and receiver) is built in the Antennas and Propagation Lab at Southern Illinois University Carbondale (SIUC) to test the coupling properties between every two identical antennas. The performance of that system is analyzed under different ii conditions to guarantee that the transmitted signal will be correctly recovered at the receiver end. The designed UWB antennas can be used in many short range applications such as wireless USB. Wireless USB is used in PCs, printers, scanners, laptops, MP3 players, hard disks and flash drives. A new technique is introduced to widen the impedance bandwidth of dielectric resonator antennas (DRAs). DRA features compactness, low losses, and wideband antennas. Different compact UWB DRAs are investigated in this dissertation. The designed DRAs cover a wide range of frequency bands such as, 6.17-24GHz, 4.23-13.51GHz, and 4.5-13.6GHz. The designed DRAs have compact sizes of 1×1×1.5cm3, 0.9×0.9×1.32cm3, 0.6×0.6×1cm3, and 0.6×0.6×0.9cm3; and cover the following frequency bands 4.22-13.51GHz, 4.5-13.6GHz, 6.1-23.75GHz, and 6.68-26.7GHz; respectively. The proposed DRAs may be used for applications in the X, Ku and K bands such as military radars and unmanned airborne vehicles (UAV).

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Lourens, Jako. "A wideband monopole antenna design." Thesis, Stellenbosch : Stellenbosch University, 2013. http://hdl.handle.net/10019.1/80026.

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Thesis (MScEng)--Stellenbosch University, 2013.
ENGLISH ABSTRACT: The successful operation of a man-pack VHF jamming system requires a compact and efficient antenna operating over a wide bandwidth. The design of such an antenna is the focus of this thesis. The antenna should be of a practical size for a portable system and it must radiate energy efficiently across a frequency bandwidth in excess of a decade. A practical „target‟ specification of such an antenna has been drawn up based on the performance of a commercially available system. Several possible antenna topologies, each with a variety of loading section options, are tested using “Full wave” electromagnetic modelling (FEKO). Each topology/loading-section is numerically optimised for load element values by considering both its gain and reflection coefficient. Results of the „optimally loaded‟ solution for each topology are then compared to each other to arrive at the best overall design. The best result is found to be the traditional monopole whip-type antenna, with four R-L loading sections spread along its length. The simulated results show that the proposed antenna can be expected to meet the target standing wave ratio (SWR) specifications while offering a gain advantage of between 5 and 10 dBi higher than is available commercially. The selected design is constructed and its performance measured.
AFRIKAANSE OPSOMMING: Die suksesvolle werking van ŉ mobiele VHF "jammer‟ benodig ŉ kompakte antenna met ŉ bruikbare benuttingsgraad wat oor ŉ wyeband funksioneer. Die ontwerp van so ŉ antenna is die fokus van hierdie tesis. Die antenna moet kompak genoeg wees om draagbaar te wees en moet ŉ bruikbare benuttingsgraad hê oor ŉ frekwensie-bandwydte van meer as 10:1. ŉ Praktiese spesifikasie is opgestel vir die antenna deur te kyk na die sigblaaie van beskikbare stelsels. “Volgolf” elektromagnetiese modelleringsagteware is daarna gebruik om ŉ parametriese ondersoek te loods van verskillende antennas. Verskillende topologieë is getoets met ʼn verskeidenheid van belaaide seksies waar die topologieë ge-optimaliseer was vir wins en weerkaatskoëffisiënt. Die resultate vir elke optimale oplossing is vergelyk.Opgrond van hierdie resultate is bevind dat die beste topologie die tradisionele monopoolmas "whip-type‟ antenna is met vier RL lading afdelings langs die lengte versprei. Analise word gebruik om te wys dat verwag kan word dat dit aan die aanwins en staande golf verhouding (SGV) spesifikasies sal voldoen met n 10 dB verhoging in aanwins vir n laer SGV. Die geselekteerde ontwerp is gebou en gemeet om te verifieer dat dit aan die spesifikasies voldoen.

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Christman, Alan M. "Validation of NEC-3 (Numerical Electromagnetics Code) with applications to MF and HF antenna technology." Ohio : Ohio University, 1990. http://www.ohiolink.edu/etd/view.cgi?ohiou1172605318.

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Tang, Ming-Chun, Zheng Wen, Hao Wang, Mei Li, and Richard W. Ziolkowski. "Compact, Frequency-Reconfigurable Filtenna With Sharply Defined Wideband and Continuously Tunable Narrowband States." IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, 2017. http://hdl.handle.net/10150/626120.

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A compact, frequency-reconfigurable filtenna with sharp out-of-band rejection in both its wideband and continuously tunable narrowband states is presented. It is intended for use in cognitive radio applications. The wideband state is the sensing state and operationally covers 2.35-4.98 GHz. The narrowband states are intended to cover communications within the 3.05-4.39 GHz range, which completely covers the Worldwide Interoperability for Microwave Access (WiMAX) band and the satellite communications C-band. A p-i-n diode is employed to switch between these wide and narrowband operational states. Two varactor diodes are used to shift the operational frequencies continuously among the narrowband states. The filtenna consists of a funnel-shaped monopole augmented with a reconfigurable filter; it has a compact electrical size: 0.235 lambda(L) x 0.392 lambda(L), where the wavelength lambda(L) corresponds to the lower bound of its operational frequencies. The measured reflection coefficients, radiation patterns, and realized gains for both operational states are in good agreement with their simulated values.

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Sokpor, Adjo Sefofo. "Conception de balises de détresse intégrées aux équipements de sécurité maritime." Thesis, Rennes 1, 2018. http://www.theses.fr/2018REN1S068/document.

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Au cours de ces dernières années, les communications sans fil connaissent une croissance vertigineuse, avec le développement de standards de communication de plus en plus nombreux, qui ouvrent la voie à de multiples applications telles que : la téléphonie mobile, le biomédical, le maritime, le civil et le militaire. De nos jours, les communications sans fil se sont diversifiées et multipliées. Cela entraîne la conception d’antennes toujours plus innovantes, performantes et de taille de plus en plus réduite (miniaturisation). Le projet FLEXBEA (FLEXible BEAcon) a pour but le développement d’un nouveau concept de balises de détresse miniatures (AIS et COSPAS-SARSAT), faible coût, intégrées dans des équipements de sécurité maritime tels qu’un radeau de survie et un gilet de sauvetage. Ces équipements sont destinés aux professionnels de la mer et aux plaisanciers. L’atout majeur de ce nouveau concept est l’intégration dans des équipements de sécurité maritime d’une fonction de détresse en cas de problème majeur : homme à la mer (MOB, Man OverBoard) par exemple lors d’un naufrage. Différentes antennes ont été étudiées. Nous présentons des antennes planaires (de type dipôle ou monopôle imprimé) développées dans la bande UHF : une solution de dipôle avec brins repliés est proposée afin de réduire l'encombrement, et deux modes d'alimentation (symétrique / dissymétrique) sont comparés. Des exemples d'antenne monopôle sont ensuite présentés avec une modification de leur géométrie (structures de type Bow-tie ou méandre) pour assurer une miniaturisation optimale. Puis les antennes filaires retenues pour le projet, avec une modélisation de ces antennes par un circuit équivalent (RLC). Des formules analytiques sont proposées afin de déterminer les valeurs de composants RLC qui interviennent dans le modèle circuit. Ensuite, nous sommes passés à la conception de l’antenne de la balise. Deux antennes ont été conçues et mesurées. Un monopôle ruban avec introduction de composants localisés pour la balise AIS et COSPAS-SARSAT, et une antenne hélice fonctionnant dans la bande AIS, intégrée dans la balise "SIMY". De nombreuses réalisations et mesures ont été effectuées pour caractériser ses antennes
Over the last few years, wireless communications have grown dramatically, with the development of more and more communication standards, which open the way to multiple applications such as: mobile telephony, biomedical, maritime, the civilian and the military. Today, wireless communications have diversified and multiplied. This leads to the design of antennas that are always more innovative, more efficient and smaller in size (miniaturization). The FLEXBEA project (FLEXible BEAcon) aims to develop a new concept of low cost miniature distress beacons (AIS and COSPAS-SARSAT) integrated into marine safety equipment such as a life raft and a lifejacket safety. This equipment is intended for professionals of the sea and boaters. The main advantage of this new concept is the integration in maritime safety equipment of a distress function in case of major problem: man overboard (MOB, Man OverBoard) for example during a shipwreck. Different antennas have been studied. We present planar antennas (dipole type or printed monopoly) developed in the UHF band: a dipole solution with folded strands is proposed to reduce the bulk, and two modes of supply (symmetrical / asymmetrical) are compared. Examples of monopole antennas are then presented with a modification of their geometry (Bow-tie or meander type structures) to ensure optimal miniaturization. Then the wired antennas selected for the project, with a modeling of these antennas by an equivalent circuit (RLC). Analytical formulas are proposed to determine the RLC component values involved in the circuit model. Then we went to the design of the beacon antenna. Two antennas were designed and measured. A ribbon monopoly with introduction of localized components for the AIS and COSPAS-SARSAT beacon, and a helix antenna operating in the AIS band, integrated into the "SIMY" beacon. Many achievements and measurements have been made to characterize its antennas

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Abreu, Antonio Salvio de. "Desenvolvimento de monopolos quase-espirais para aplica??es em sistemas UWB." Universidade Federal do Rio Grande do Norte, 2009. http://repositorio.ufrn.br:8080/jspui/handle/123456789/15289.

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This work is the analysis of a structure of the microstrip antenna designed for application in ultra wide band systems (Ultra Wideband - UWB). This is a prospective analytical study where they tested the changes in the geometry of the antenna, observing their suitability to the proposed objectives. It is known that the UWB antenna must operate in a range of at least 500 MHz, and answer a fractional bandwidth greater than or equal to 25%. It is also desirable that the antenna meets the specifications of track determined by FCC - Federal Communication Commission, which regulates the system in 2002 designating the UWB bandwidth of 7.5 GHz, a range that varies from 3.1 GHz to 10, 6 GHz. by setting the maximum power spectral density of operation in -41.3 dB / MHz, and defining the fractional bandwidth by 20%. The study starts of a structure of geometry in the form of stylized @, which evolves through changes in its form, in simulated commercial software CST MICROWAVE STUDIO, version 5.3.1, and then tested using the ANSOFT HFSS, version 9. These variations, based on observations of publications available from literature referring to the microstrip monopole planar antennas. As a result it is proposed an antenna, called Monopole Antenna Planar Spiral Almost Rectangular for applications in UWB systems - AMQEUWB, which presents simulated and measured results satisfactory, consistent with the objectives of the study. Some proposals for future work are mentioned
Este trabalho consiste na an?lise de uma estrutura de antena de microfita projetada para aplica??o em sistemas de banda ultra larga (ultra wideband UWB). Trata-se de um estudo prospectivo e anal?tico onde s?o experimentadas as modifica??es na geometria da antena, observando-se sua adequa??o aos objetivos propostos. Sabe-se que a antena UWB deve operar numa faixa de no m?nimo 500 MHz, e atender uma banda fracion?ria maior ou igual a 25%. ? desej?vel ainda, que a antena atenda ?s especifica??es de faixa determinadas pela FCC Federal Communication Commission, que em 2002 regulamentou o sistema UWB designando a largura de banda de 7,5 GHz, numa faixa que varia de 3,1 GHz a 10,6 GHz. fixando a densidade espectral de pot?ncia m?xima de opera??o em -41,3 dBm/MHz, e definindo a banda fracion?ria em 20%. O estudo parte de uma estrutura de geometria em forma de @ estilizada, que evolui atrav?s de modifica??es na sua forma, simuladas nos softwares comerciais CST MICROWAVE STUDIO, vers?o 5.3.1, e, em seguida, testado com o uso do ANSOFT HFSS, vers?o 9. Varia??es estas, com base em observa??es de publica??es dispon?veis na literatura, referentes a antenas de microfita monopolo planar. Como resultado ? proposta uma antena, denominada Antena Monopolo Quase-Espiral Planar Retangular para aplica??es em sistemas UWB AMQEUWB, que apresenta resultados simulados e medidos satisfat?rios, coerente com os objetivos do estudo. Algumas propostas para trabalhos futuros est?o citadas

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Jedlicka, R. P., and J. M. Williamson. "Monopatch Antenna for Balloon Telemetry Applications." International Foundation for Telemetering, 1992. http://hdl.handle.net/10150/611958.

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International Telemetering Conference Proceedings / October 26-29, 1992 / Town and Country Hotel and Convention Center, San Diego, California
A new antenna design, which is particularly suited for balloon telemetry applications, is presented. In the past, simple monopoles have been utilized as transmit antennas on balloon payloads. The monopole radiation pattern has an inherent null along its axis. This causes an undesirable loss of signal when the balloon is directly overhead. To prevent this occurrence, a microstrip antenna patch was incorporated into the monopole design. This combination, a "monopatch" antenna, provides sufficient coverage even when the balloon is directly over the ground station. The monopatch has been successfully flown on high altitude balloon flights.

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Silva, Marcelo Ribeiro da. "Novas configura??es de monop?lios planares quase-fractais para sistemas de comunica??es m?veis." Universidade Federal do Rio Grande do Norte, 2008. http://repositorio.ufrn.br:8080/jspui/handle/123456789/15211.

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Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior
The characteristic properties of the fractal geometry have shown to be very useful for the construction of filters, frequency selective surfaces, synchronized circuits and antennas, enabling optimized solutions in many different commercial uses at microwaves frequency band. The fractal geometry is included in the technology of the microwave communication systems due to some interesting properties to the fabrication of compact devices, with higher performance in terms of bandwidth, as well as multiband behavior. This work describes the design, fabrication and measurement procedures for the Koch quasi-fractal monopoles, with 1 and 2 iteration levels, in order to investigate the bandwidth behavior of planar antennas, from the use of quasi-fractal elements printed on their rectangular patches. The electromagnetic effect produced by the variation of the fractal iterations and the miniaturization of the structures is analyzed. Moreover, a parametric study is performed to verify the bandwidth behavior, not only at the return loss but also in terms of SWR. Experimental results were obtained through the accomplishment of measurements with the aid of a vetorial network analyzer and compared to simulations performed using the Ansoft HFSS software. Finally, some proposals for future works are presented
As propriedades ?nicas da geometria fractal t?m-se mostrado bastante ?teis para a constru??o de filtros, superf?cies seletivas em freq??ncia, circuitos sintonizados e antenas, possibilitando solu??es otimizadas para uma variedade de usos comerciais na faixa de microondas. A geometria fractal est? inclu?da na tecnologia dos sistemas de comunica??o por microondas devido a algumas propriedades interessantes para a fabrica??o de dispositivos compactos, com desempenho superior em termos de largura de banda, bem como, comportamento multibanda. Neste trabalho, descrevem-se os procedimentos para o projeto, constru??o e medi??o de monopolos quase-fractais de Koch, com n?veis 1 e 2, projetados para se investigar o efeito produzido na largura de banda de antenas planares, a partir da utiliza??o de estruturas quase-fractais nos seus patches retangulares. O efeito eletromagn?tico da varia??o do n?vel dos fractais, bem como, da miniaturiza??o das estruturas, foram avaliados. Tamb?m foram realizadas parametriza??es com o intuito de se verificar o comportamento da largura de banda, tanto para a perda de retorno quanto para o SWR. Os resultados foram obtidos atrav?s de medi??es realizadas por um analisador de redes vetorial e por meio de simula??es no Ansoft HFSS. Algumas propostas para trabalhos futuros foram citadas

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Sun, Xiaolei, and 孙肖磊. "Dual-band and frequency-reconfigurable monopole antennas." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2013. http://hub.hku.hk/bib/B50899880.

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The designs of three compact dual-band monopole antennas for wireless-local-area-network (WLAN)applications are presented. In these designs, an L-or U-shaped monopole element with microstrip-fed is used to generate a high-frequency band at around 5.5 GHz to cover the high WLAN bands at 5.2/5.8GHz for the IEEE 802.11a standard. An E-shaped element, loop element or meander-microstrip ground stub element with coupled-fed through the monopole element is used to generate a low-frequency band at around 2.4 GHz to cover the low WLAN band for the IEEE 802.11b/g standards. With such arrangements, the three antenna shave very compact radiators of only 11.3×8 mm2,12.6×9 mm2and11.8×9.4 mm2. To investigate the performances for practical uses, these antennas are also designed on a mobile-phone printed-circuit board and studied using computer simulation and measurement. Dual-band antennas with reconfigurable Dual-band antennas with reconfigurable lower band, higher band and dual-band are designed in this thesis. The dual-band antenna consists of two radiating branches generating the frequency bands at around 2.4 GHz and 3.5 GHz for the WiMAX system. Varactors are placed on the corresponding branches for continuously tuning of the operating bands for different WiMAX standards. For frequency tuning of the lower band or higher band, simple and novel DC biasing circuits without requiring any soldering wire are proposed to bias the varactor on a radiating element. While for simultaneous frequency tuning of the two individual bands, simple and novel DC biasing circuits requiring two soldering wires are proposed to bias the varactors on the radiating elements. Both simulation and measurement results show that the DC biasing circuits designed have very little affects on the antennas performances. The design of a monopole ultra-wide band (UWB)antenna with a reconfigurable notch band is presented. The antenna employs a vertical-ellipse radiator to achieve an UWB. A compact defected-ground structure (DGS)is used to create a notch band for the antenna. To frequency tune the notch band, a varactor is placed on the DGS to control the resonance frequency. The tuning performance, in terms of reflection coefficient, radiation pattern, efficiency and gain, of the antennais studied using simulation and measurement. Results show that the notch band can be tuned continuously from 5.2 to 6.32 GHz for the WLAN bands. In the measurement of a monopole antenna with a small ground plane, the feeding cable used to connect the antenna to the measurement equipment Satimo Starlab system causes discrepancies between the simulated and measured radiation patterns, efficiencies and peak gains at lower frequencies. In the designs of antennas in this thesis, the cable effects are studied by modeling the feeding cable using the EM simulation tool CST. Results show that, by using the cable model, the simulated and measured results agree very well.
published_or_final_version
Electrical and Electronic Engineering
Doctoral
Doctor of Philosophy

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Schreiber, Adam Wesley. "Efficient analysis of loaded cylindrical monopole antennas." Connect to this title online, 2009. http://etd.lib.clemson.edu/documents/1256570757/.

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Hurley, Robert C. "Computation of monopole antenna currents using cylindrical harmonic expansions." Thesis, Monterey, California. Naval Postgraduate School, 1988. http://hdl.handle.net/10945/22966.

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Approved for public release; distribution is unlimited
This thesis investigates the viability of a new method for numerically computing the input impedance and the currents on simple antenna structures. This technique considers the antenna between two ground planes and uses multiregion cylindrical harmonic expansions with tangential field continuity to obtain the surface currents and input impedance. The computed results are compared to the results obtained from the Numerical Electromagnetics Code for various physical parameters to assess computational accuracy.
http://archive.org/details/computationofmon00hurl
Lieutenant, United States Navy

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Elliniadis, Panagiotis. "An investigation of near fields for HF shipboard antennas: surface PATCH and wire grid modeling using the Numerical Electromagnetics Code." Thesis, Monterey, California. Naval Postgraduate School, 1988. http://hdl.handle.net/10945/23280.

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Approved for public release; distribution is unlimited
The Numerical Electromagnetics Code (NEC) was used to evaluate the admittance, average power gain, and the electric near and far field of a monopole antenna mounted on a cubical box over a perfectly conducting ground plane. Two models of the box, employing surface patches and wire grids, were evaluated. The monopole was positioned at the center, the edge, and at a corner of the box's top surface. Admittance and average power gain of the antenna were calculated. NEC results were examined and compared with experimental data and with results from "PATCH", another independent electromagnetic modeling code. The near electric field was calculated for both models. Computer graphics techniques were presented for plotting NEC near field results using DISSPLA (Display Integrated Software System and Plotting Language), a commercial graphics package. Contour and 3-D amplitude, and phase plots of the near electric fields were presented. Radiation patterns were calculated to relate far field and near field behavior of the antenna. Surface patch and wire grid models are compared and conclusions were presented.
Naval Ocean Systems Center
http://archive.org/details/investigationofn00elli
O&MN, Direct Funding
Lieutenant, Hellenic Navy

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Hussain, Asif Jamshaid. "Design of an Ultra Wideband (UWB) Circular Disc Monopole Antenna." Thesis, Linnéuniversitetet, Institutionen för datavetenskap, fysik och matematik, DFM, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:lnu:diva-34605.

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My task was to design a circular disc monopole antenna in the Ultrawideband range i.e. 3.1 - 10.6 GHz using the ADS (Advanced Design System) package. In order to achieve the desired matching I simulated dierent sizes of the radiator, feed line and the ground plane of the antenna and observed the current flow in a circular monopole at different frequencies. I did some miniaturization (circular shape and chopping) of the antenna and observed the current flow and radiation pattern in 2D and 3D.

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Lima, Larissa Cristiane Paiva de Sousa. "Design and experimental characterization of a metamaterial-assisted monopole antenna." Universidade de São Paulo, 2014. http://www.teses.usp.br/teses/disponiveis/18/18155/tde-12112014-080528/.

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In recent years a new class of materials, the metamaterials, has emerged in the scientific community. The use of these materials makes possible to achieve unique electromagnetic properties, such as the negative refractive index. Today there exist several applications that take advantage of these special properties, such as sensors, antennas and invisibility cloaks, aiming at improving their intrinsic characteristics. Based on these considerations, this project aims at developing metamaterials structures to control the radiation properties of antennas in the microwave range, such as gain and directivity. More specifically, it was also chosen chiral metamaterials, mainly due to the phenomenon of electromagnetic field rotation which opens the possibility to control efficiently the radiation properties of antennas. In addition, chiral metamaterials, which have proved to be a more attractive alternative to obtain negative or zero refractive index, enable a greater degree of freedom in the design of different structures. This work encompasses all different phases of the structure design, namely: project, computational modeling, fabrication, and characterization of the proposed structures. We show improvements for the gain that in some cases reaches more than the double of the conventional monopole antenna gain and for the return loss parameter, which reaches minimum values. We also could maintain good efficiency and improve the input impedance matching. Finally, it is worth mentioning that this new technology also has the great potential to be applied in the telecommunication devices, particularly to improve communications based on antennas.
Nos últimos anos uma nova classe de materiais, os metamateriais, emergiu na comunidade científica. O uso desses materiais torna possível alcançar propriedades eletromagnéticas singulares, como o índice de refração negativo. Hoje existem vastas aplicações que usufruem destas propriedades especiais, como os sensores, mantas de invisibilidade e antenas, onde se procura o aperfeiçoamento de suas características intrínsecas. Com base nestas considerações, este projeto buscou desenvolver estruturas metamateriais para controle das propriedades de radiação de antenas na faixa de micro-ondas, tais como diretividade e ganho. Mais especificamente, foram utilizados os metamateriais quirais, principalmente devido ao fenômeno de rotação do campo eletromagnético que abre a possibilidade de controle mais eficiente das propriedades de radiação de antenas. Além disso, os metamateriais quirais, por se mostrarem uma alternativa mais atraente para se obter meios com índice de refração zero ou negativo, possibilitam um maior grau de liberdade no projeto de diferentes estruturas. Este trabalho contempla, ainda, todas as etapas de projeto de tais estruturas, quais sejam: projeto, modelagem computacional, fabricação, e caracterização das estruturas. Mostramos melhorias para o ganho que, em alguns casos, chega a mais do que o dobro do ganho da antena monopolo convencional e para o parâmetro de perda de retorno, que atinge valores mínimos. Nós também mantivemos uma boa eficiência e melhoramos o casamento de impedância de entrada. Finalmente, vale salientar que essa nova tecnologia também apresenta grande potencial de ser aplicada em dispositivos de telecomunicações, com o intuito de aprimorar a comunicação baseada em antenas.

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17

Nguyen, Trong Nghia. "Analysis, design and optimisation of various antenna types based on equivalent magnetic-current concept." Thesis, 2017. http://hdl.handle.net/2440/115415.

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The field equivalence principle is a classical technique, simple to use but remarkably effective to analyse aperture antennas. For most of thin planar structures, the aperture can be approximated as perfect magnetic conductor. Thus, the field equivalence principle typically yields a well-approximated equivalent problem that is much easier to solve than the original geometry. Inspired by this principle, a wide range of novel antenna structures are proposed in this thesis. These structures are further developed, optimised and tailored for various practical applications. Three main types of antennas are investigated, including travelling-wave antennas, low-profile monopolar antennas and reconfigurable antennas, corresponding to three major parts of this dissertation. The first part examines various realisations of travelling-wave half-mode substrate- integrated waveguide (HMSIW) antennas and their optimisations. This type of antenna is equivalent to a magnetic dipole. In this part, the core contribution is a generalised semi-analytical model to effectively analyse continuous-source travelling-wave antennas, based on which different optimisation techniques for bandwidth and radiation patterns are proposed. An optimisation procedure that includes parameter uncertainties is also demonstrated. The second part focuses on a type of low-profile monopolar antennas that can be interpreted as magnetic-current loops using the field equivalence principle. The main contributions are different configurations of symmetrical radiating slots that act as additional magnetic-current loop sources. The last major part covers a wide range of reconfigurable antennas targeting various applications. These includes a family of stub-loaded substrate-integrated antennas, a circular resonant cavity, and low-profile monopolar antennas that have been introduced in the second major part. These antennas not only cover three main application types of reconfigurable antennas, i.e. frequency- , polarisation-, and pattern-tunability, but also combine those in a single device. Moreover, significant improvements in performances compared to antennas available in the literature are demonstrated. Overall, the thesis provides different frameworks to design many types of antennas. The analytical models, using the field equivalence principle as a common fundamental technique, provide not only thorough understandings on antennas’ radiation mechanisms but also an effective means for rapid antenna optimisations.
Thesis (Ph.D.) -- University of Adelaide, School of Electrical and Electronic Engineering, 2017

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18

See, Chan H., Hmeda I. Hraga, Raed A. Abd-Alhameed, Neil J. McEwan, James M. Noras, and Peter S. Excell. "A Low-Profile Ultra-Wideband Modified Planar Inverted-F Antenna." 2013. http://hdl.handle.net/10454/9727.

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No
A miniaturized modified planar inverted-F antenna (PIFA) is presented and experimentally studied. This antenna consists of a planar rectangular monopole top-loaded with a rectangular patch attached to two rectangular plates, one shorted to the ground and the other suspended, both placed at the optimum distance on each side of the planar monopole. The fabricated antenna prototype had a measured impedance bandwidth of 125%, covering 3 to 13GHz for reflection coefficient better than -10 dB. The radiator size was 20 x 10 x 7.5 mm(3), making it electrically small over most of the band and suitable for incorporation in mobile devices. The radiation patterns and gains of this antenna have been cross-validated numerically and experimentally and confirm that this antenna has adequate characteristics for short range ultra-wideband wireless applications.

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19

Siao, Sin-long, and 蕭新朧. "Miniaturized GPS chip antenna and multiband monopole antenna." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/09486805850704632333.

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碩士
國立臺灣科技大學
電機工程系
97
For future communication systems, to simultaneously meet various requirements such as low profile, compact size, light weight and easy fabrication, the dimension consideration of antenna design is a very critical part. The radiation performance of the antenna also directly affects the received signal and communication quality. Therefore this thesis proposes a miniature GPS antenna to be built in the mobile phone, PDA and smart phone for obtaining the satellite signals. A commercial EM solver, HFSS has been utilized to design prototype and investigate the performance variation for antenna located at different positions in the test board. Moreover, a multi-band monopole antenna is also presented to integrate more wireless access functions. The operating band of the proposed antenna is composed of GSM, DCS, PCS, UMTS, Bluetooth, WLAN、WiMax, Hyper LAN, WWAN and WiFi. As to achieve a better radiation performance, the antenna also employs two back-strips to enhance more resonant frequencies and flexibly adjust input impedance in this study.

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20

蔡文益. "Broadband Fractal Circular-Monopole Antenna." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/ejrb2e.

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碩士
景文科技大學
電腦與通訊研究所
99
In this paper, a novel broadband Fractal circular-monopole antenna is presented. This antenna consists of printed circular iteration with two iterating level and ground-plane with radius 25mm, making it easy to making it easy to combine directional, high gain and wide bandwidth. A prototype is designed to operate at 1.5GHz-5.86GHz, the measured 10 dB bandwidth is nearly 1:2 at the center frequency of 3.775GHz. Experimental results are shown to verify the validity of theoretical work. Fractal monopole antenna is formed with hollow of circle, which featuring of minification, multi-frequency bands and wide bands. The planar fractal monopole antenna is based on the Sierpinski carpet concept and to modified, the Sierpinski fractal has generated two iterations, use the decomposition algorithm by circular, and compare these with integrators and initiator type. Firstly, base on generally circular disc to generate hollow of circular, this initiator has a circumference of and 1mm trace width. In the decomposition algorithm, a geometric ratio of circle is taken and joining the midpoints of union of the circles central, reduce the circle to 1/3 diameter and canonical Sierpinski carpet algorithm to fill the circle with twice mathematics equals 1/9 diameter by 2nd iteration.The geometrical structure and dimensions of the proposed monopole type antenna is printed on FR4 substrate and is simulated by using FEM based electromagnetic simulator, Ansoft HFSS. All of them describe a multiband behavior of fractal antenna. This behavior is consistent from the input return loss and gain; moreover radiation patterns planes of view. The same scale factor existing among similar structures in the fractal circular-shape. It can be summarized that the self-similarity properties of the fractal structure are translated into its electromagnetic behavior. The current density distributions have a similar and vary in complicated among bands as well. Such distributions allows flexibility in matching multi- and width band operations in which a larger frequency required, such as FemtoCell and UMTS base station application including LTE, UMTS, GPS L1, WIFI, and WiMax. The circular monopole type is based on fractal structure and refers to the Sierpinski gasket self-similarity algorithm, a prototype of the design is successfully implemented with close agreement between measurement and simulation. The fractal geometry and overall size can be effectively utilized ID or Logo surface for integrating with other components in IT products.

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21

Huang, Hao-Shiang, and 黃晧翔. "Circularly Polarized Monopole Antenna Designs." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/07486773061579913898.

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碩士
國立高雄海洋科技大學
電訊工程研究所
102
In this dissertation, circularly polarized (CP) monopole antenna designs for industrial, scientific and medical (ISM) band are proposed. First, by properly introducing dual strip-sleeves shorting at the ground plane, the antenna design provides the impedance bandwidths (RL≧10 dB) of 270 / 988 MHz and the 3 dB axial-ratio (AR) bandwidth of about 85/710 MHz for 2.4/5.2 GHz wireless local area network (WLAN) applications, respectively. The proposed planar antenna reduces the antenna size by at least 22% since the overall antenna size is only 40 × 40 × 1.6 mm3. Meanwhile, the measured peak gains and antenna efficiencies are about 4.2/3.2 dBic and 95/90% across the operating bands, respectively. Next, two spiral monopole antennas with radial and axial circular polarization, respectively, are proposed with the impedance bandwidth of 135/218 MHz and the 3 dB axial-ratio (AR) bandwidth of about 108/125 MHz across 2.45 GHz operating band. Furthermore, the measured peak gains and antenna efficiencies are about 9/10 dBic and 85/80%, respectively. Finally, the analysis of the body specific absorption rate (SAR) for two proposed spiral monopole antennas are discussed and less than 1.6W/kg for 1-g body tissue.

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22

CHEN, GUAN-LIN, and 陳冠霖. "Circularly Polarized Monopole Antenna Designs." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/80716486991789568103.

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碩士
逢甲大學
電機工程學系
105
This paper studied the circularly polarized RFID reader antenna. The first antenna is a compact circularly polarized monopole antenna. It is fed by a microstrip line. By adjusting the parameters of the left branch and right branch, a circularly polarization with good impedance matching can be obtained. The overall dimension of the first proposed antenna is 60×60×0.8 mm3. The measured 10-dB return loss bandwidth of the antenna is 93.4 MHz (901 – 993.4 MHz, 9.3%), 3-dB axial ratio bandwidth is 12 MHz (916 – 928 MHz, 1.3%), the maximum gain and radiation efficiency are -1.1 dBic and 70%, and antenna has bidirectional radiation characteristics. The half-power beamwidths antenna in XZ plane and YZ plane are 170 degrees and 115 degrees respectively. The first proposed antenna is a low profile, compact size, low cost antenna, which is suitable for portable UHF RFID reader application. The second proposed antenna uses AMC reflector to enhance the gain of the antenna. The AMC reflector periodic structure is placed 9 mm away from the bottom of the antenna for the optimal configuration. The measured 10-dB return loss bandwidth is 650 MHz (2.08 – 2.73 GHz, 27%), 3-dB axial ratio bandwidth is about 120 MHz (2.6 – 2.72 GHz, 4.5 %); the best axis ratio is 1.29 (2.65 GHz), and the measured gain is 6.5 dBic. The front-to-ratios in XZ plane and YZ plane are both about 22 dB. The overall dimension of the second antenna is 80×80×12.2 mm3.

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23

Wang, wei-ming, and 汪偉銘. "Compact Dipole Antenna and Multi-band Monopole Antenna Applications." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/20665209134079983350.

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碩士
明志科技大學
電機工程研究所
100
The three compact structure of dual-band and multi-band operation antennas are proposed in this paper. The resonant path are based on resonating at a quarter and a half wavelengths. By using branch loop and coupling resonant, it can satisfy achieve the required band. Firstly, a dipole antenna suitable for Bluetooth, WLAN and WiMAX applications is proposed. The antenna is composed of two pairs of T-shaped and U-shaped sections, can achieve a compact size of 6(W)*35(L)mm2 FR4 substructure, With 10 dB return loss, two operating frequency bands covering 2.4-2.55 and 4.99-6 GHz can be obtained with our design. Second, a monopole antenna suitable for GSM/DCS/PCS/UMTS applications is proposed. The antenna is composed of the loop and the coupling resonance, can achieve a compact size of 15(W)*50(L)mm2 FR4 substructure, With 6 dB return loss, two operating frequency bands covering 0.86-0.96 and 1.71–2.17 GHz can be obtained with our design. Third, a folded loop antenna suitable for GSM/DCS/PCS/UMTS applications is proposed. The antenna by the resonance loop composed, can achieve a compact size of 20(W)*50(L)mm2 on copper substructure, With 6 dB return loss, two operating frequency bands covering 0.86-0.96 and 1.71–2.17 GHz can be obtained with our design.

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24

Tsai, Ming-Li, and 蔡明利. "Study of Monopole Antenna and Chip Antenna for Wireless Communication." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/80574470213960999487.

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碩士
國立臺灣科技大學
電子工程系
96
In this thesis, we will design planar antenna and semiconductor chip antenna, of the wireless communication. We discuss planar antenna implemented by directly printing conducting metal on the substrate (FR4) to have the advantages of compact size, manufacturing convenience, reduction of cost, and easy combination to other circuits. We adopt the whole simulation software IE3D simulate the properties of antenna, and realize antenna with RF-4 board again in this text, use network analysis and chamber to examine the S-parameter and patterns of antenna. We probe into the design of the semiconductor chip antenna in chapter four, and apply chip antenna with inductance value to a replace the inductor in traditional voltage-controlled oscillator.

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25

Lin, Yen-Chih, and 林彥鋕. "CPW-Fed Circularly Polarized Monopole Antenna." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/36587086447920777634.

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碩士
逢甲大學
產業研發碩士班
95
In this thesis, a CPW-fed circularly polarized monopole antenna has been implemented and investigated. The simulated and measured results of the antennas are detailed and analyzed. First, a new antenna possessing linear polarization and circular polarization for applications of the global positioning system (GPS) and digital communication system (DCS) has been designed. The proposed antenna consists of two parts: a quasi-C-shaped monopole antenna and an inverted L-shaped strip connecting to ground plane. By introducing a gap between the monopole antenna and inverted L-shaped strip, a traveling-wave current is excited on a loop trace. Meanwhile, by utilizing the electromagnetic coupling effect inside the gap, the vertical and horizontal electric fields with the phase difference of 90 degree and the equal magnitude result in the circularly polarized radiation in the free space at the 1.5 GHz band (GPS). The resonant band at 1.8 GHz (DCS band) is determined by the effective length of the quasi-C-shaped monopole antenna. Finally, the optimal dimensional values of the antenna are derived by tuning the critical parameters in order to obtain the maximum bandwidth and desired circular polarization。 The advantages of the new proposed antenna are miniaturization, dual-system operation, circular polarization and easy fabrication. The proposed antenna can be a candidate of the RX/TX radiator for the integration of GPS and DCS systems.

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26

WANG, JIAN-CHENG, and 王健丞. "CPW Monopole Antenna Application Circular Polorization." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/26wa3a.

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碩士
大葉大學
電機工程學系
104
This paper presents to the CPW fed monopole antenna can be use in global positioning system(GPS)and 4G(LTE).This antenna thourgh suitable cutting one side of a metal ground plane, so that the original monopole resonance disappears, forming a dipole resonance, and output and has two orthogonal linearly polarization 90° to achieve circular polarization. On the other side of the metal ground plane, with inverted L-shaped metal patch antenna bandwidth is increased so that the coating on the 4G(LTE)band.In addition, the antenna design can be simple,low -cost production, and easy to combine with the microwave components.

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27

Chang, Teng-Yuan, and 張燈元. "Dual Broadband Bow-Tie Monopole Antenna." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/26574087388647171013.

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碩士
國立澎湖科技大學
電資研究所
102
This paper presents the designs of three dual broadband bow-tie monopole antennas. The frequencies are designed to meet the applications of the four bands GSM/WLAN/WiMAX/LTE. That is, the low-frequency and high-frequency bands cover 1.71~2.69 GHz (44.55%) and 5.18~5.825 GHz (11.72 %) individually, with input reflection coefficient -10dB level. The first antenna is formed by a bow-tie monopole antenna and a rectangular ring antenna, which is named ringed dual broadband bow-tie antenna. The second antenna is named half-wavelength slot dual broadband bow-tie antenna, which is a broadband bow-tie antenna embedded a half-wavelength slot to generate dual broadband. The third antenna is named quarter wavelength slot dual broadband bow-tie antenna, which is embedded with two open-end quarter-wavelength slots. Using the above mentioned three different methods to design dual broadband monopole antenna, simulated frequency bands are all up to 30% bandwidth. Ring dual broadband bow-tie antenna is implemented and measured. The low-frequency band is 2.19~3.06 GHz (33.14%) and the high-frequency band is 5.3~6.45 GHz (19.57%). The measured results of this half-wavelength slot dual broadband bow-tie antenna are the low-frequency band 1.95~2.65 GHz (30.43%) and the high-frequency band 4.79~6.8 GHz (34.69%). The last 1/4 wavelength slot dual broadband bow-tie antenna with the largest bandwidth can cover GSM/WLAN/WiMAX/LTE band, which the experimental measurements are included the low-frequency band 1.66~2.73 GHz (48.75%) and the high frequency band 4.89~7.00 GHz (35.49%). In addition, as measured results, the S11 and radiation pattern of the designed antenna are roughly consistent with the numerical simulation to verify the feasibility of the antenna design methods mentioned in this paper.

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28

LEE, Kuo-ching, and 李國清. "Planar Triple-band Monopole Antenna Design." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/83782110877053611411.

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碩士
國立臺灣科技大學
電子工程系
96
The aim of this thesis is to design the triple-bands mono-pole antenna, which was made by common material named FR4 board purchased from the market. Literature survey studied from dual-bands and triple-bands’ papers and these as the fundamental structure; the implementation performed by electromagnetic analysis program named IE3D to do fine tuning antenna and come out simulation results. The optimized parameters had been resolved for making actual antenna product. The proposed planar mono-pole antenna has excellent function upon WiMAX and WLAN frequency bands (2500-2690/3400-3690/ 5250-5850 MHz for WiMAX) and (2.4-2.484 GHz and 5.15-5.35 GHz、5.725-5.825 GHz for WLAN); This antenna also could support frequency bands for PCS(1.85 ~ 1.99 GHz) and UMTS (1.92 ~ 2.17 GHz) with acceptable performances. It should be a good product applying to industrial enterprise.

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29

Chien, Wu-cheng, and 簡武正. "BROADBAND MONOPOLE ANTENNA FOR DVB-T." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/54365269513755483306.

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碩士
大同大學
通訊工程研究所
99
In the thesis, a wideband monopole antenna for the European DVB-T (Digital Video Broadcast-Terrestrial) system specification is proposed. This paper uses the theory of traditional monopole antenna and impedance matching with the appropriate adjustment method to meet the DVB-T frequency band specification(470 MHz to 862 MHz), the monopole antenna in order to meet the DVB-T specification, firstly, adjusted the length and width of antenna to meet the low-frequency part of the DVB-T, followed by a patch with inset feeding configuration is used and adjust the feed line to the appropriate width ratio, and effective enough to increase the impedance bandwidth to cover the DVB-T requirements specification band. After actual results of the measurement of the impedance bandwidth and radiation characteristics are consistent with the simulation, the proposed antenna can be applied to DVB-T.

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30

Luo, Shih-Cing, and 羅仕清. "Study of Broadband Monopole Slot Antenna Feed." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/03680026198637219053.

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碩士
明新科技大學
電機工程系碩士班
104
In this thesis, we study separately the asymmetric coplanar waveguide fed and the U-shaped coplanar waveguide fed monopole slot antennas. The Implement of antenna is carried out with printing circuit boards, which are easy to be integrated, low cost and enhancing convenience production characteristics. In this study, two different locations of feed are applied for the monopole slot antenna. The resonant modes of the antenna are excited by different current paths. In asymmetric coplanar waveguide feed case, by changing the location and shape of the feed, the asymmetric coplanar waveguide fed monopole slot antenna has operating frequency from 2.55GHz to 6.2GHz with operating bandwidth 85%. The U-shaped coplanar waveguide fed monopole slot antenna has operating frequency between 2.3GHz and 5.4GHz with bandwidth is 82%. The operating bands of these antennas are including Bluetooth ,WLAN and WI-MAX, which can be applied for wireless network. The bandwidth is more than 25% (500MHz above) and fits in the definition of ultra wide band.

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31

LU, BO-RU, and 盧柏儒. "Broadband C-Shaped Circularly Polarized Monopole Antenna." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/87950526255852096732.

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碩士
大葉大學
電機工程學系
104
This thesis discusses is designed and improve the Broadband C-Shaped monopole. The antenna is reference by C-Shaped, and add a rectangle and open-loop in ground plan to achieve width bandwidth and axial ratio. Advantages of the antenna are simple structure, compact size , width bandwidth and axial ratio. Objective to cover the WLAN 5 GHz (4.915 - 5.825 GHz) bandwidth.

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32

CHIU, PEI-YUAN, and 邱培源. "Printed monopole antenna designs for WLAN applications." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/81988507648488590921.

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碩士
國立高雄師範大學
物理學系
94
In this thesis, printed monopole antenna designs for the purpose of wider impedance bandwidths which can cover the 2.4/5.2/5.8 GHz triple-band WLAN operations are presented. Firstly, two innovative printed monopole antenna designs of different shape are proposed in Chapter 2 and 3, both designs have two different resonant paths for controlling the lower and upper resonances easily. Secondly, the printed monopole antenna design with one resonant path, and folded by a shorting pin is studied in Chapter 4. Simply by adding the parasitic element, as well as the generating of electromagnetic coupling between the resonant paths, all designs above-mentioned can easily achieve the WLAN 2.4/5.2/5.8 GHz triple-band operations.

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33

Chung, Wen-Tsan, and 鐘文燦. "Design of Monopole Antenna for UWB Application." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/87643305311038735814.

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碩士
國立彰化師範大學
電子工程學系
97
In this thesis, ultra-wideband (UWB) antenna design using microstrip-fed were studied. Three different UWB antenna structures were designed, implemented, and investigated. The first antenna studied is an octagonal-shaped ultra-wideband printed antenna. Its UWB operation within the required 3.1–10.6 GHz frequency range is achieved by simply embedding a small rectangular slit in the ground plane under the feed line of the octagonal patch. With the dimensions (length and height) of the slit carefully tuned, the vital information on how the various parameters affect the impedance matching is provided. The second proposed antenna is the follow-up design of the first proposed one, where the band-notch function is achieved by embedding two additional symmetrical L-shaped slits at both sides of the ground plane. The gain and time-domain characteristics of this antenna show that it is applicable to any wireless communication system that requires a stable signal transmission in the 5-GHz notch-band excluded UWB. Finally, a compact microstrip-fed monopole antenna for application in the WLAN (2.4-2.484 GHz) and UWB bands is designed and investigated. The radiating element of the proposed antenna consists of two arms which resonate at the fundamental frequencies of 2.45 and 3.5 GHz, respectively. A narrow slot is purposely embedded in the ground plane under the microstrip feed line to improve the impedance matching for the higher-order modes of the two radiating arms for achieving an ultra-wideband response. A prototype of the designed antenna is fabricated and measured, and satisfactory radiation properties were observed.

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34

Pan, Po-Yu, and 潘柏宇. "Study of Multiband Monopole Antenna for LTE." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/3jrg8n.

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碩士
義守大學
電機工程學系
102
Antenna device needs to be able to send and receive signals in wireless network communications. As technology advances, Mobile band from the early GSM 900/1800 (2G) and now widely used cellphone multimedia transmission UMTS 2100 (3G) and is developing LTE 700/900/1800/2600 (4G). This paper presents the multiband antennas applicable for LTE, this antenna have three- frequency band, the main design principles combined with G-type monopole antenna and L-type monopole antenna, with two different shapes monopole excitation frequency to complete. First, use of G-type monopole antenna structure resonance of 700MHz/1800MHz modal, then by adding L-shaped monopole antenna structure to increase the resonance path length, in addition to produce 2600MHz modal. The design frequency bands are for LTE 700/1800/2600. The simulator HFSS is employed for simulation and results show that 700/1800/2600MHz are included in the band.

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35

Cheng, Yu-Wei, and 程昱瑋. "Design of the CPW-fed Monopole Antenna." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/y98488.

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碩士
國立臺南大學
電機工程學系碩博士班
103
A novel coplanar-waveguide (CPW)-fed monopole antenna with dual-band circular polarization (CP) has been demonstrated in this work. A simple two-finger fork-like strip monopole, which is fed at the CPW feeding line, is designed to resonate at the 1.57 GHz; in addition, the resonant mode also excites a right-hand circularly polarized (RHCP) wave for applications of the global positioning system (GPS). A rectangular patch is added at the end of one finger to generate a horizontal current component, thus enhancing the CP performance. A left-hand circularly polarized (LHCP) wave at 2.33 GHz for the satellite digital audio radio (SDAR) service system is excited by modifying the geometry of the ground plane. To improve the CP performance at the SDAR band, a short stub is added at the left side of the ground plane. Only two resonances are merged and then a moderate impedance bandwidth is obtained. The measured impedance bandwidth of a reflection coefficient (S11) < -10 dB ranges from 1.49 to 2.92 GHz, and thus covers most of the commercial wireless communication systems. The 3-dB axial ratio (AR) bandwidths are about 40 MHz at the lower band (1.57 GHz) and 290 MHz at the upper band (2.33 GHz).

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36

Xin, Ming-Quan, and 辛明泉. "Omnidriectional Multi-band Low-profile Monopole Antenna." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/32746854466881735539.

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碩士
正修科技大學
電子工程研究所
95
In this thesis, a series of low-profile monopole antennas with multi-band operation is addressed. The proposed antennas are suitable for applications in mobile phones for GSM (Global System for Mobile communication, 890-960 MHz), DCS (Digital Communication System, 1710-1880 MHz), and PCS (Personal Communication System, 1850-1990 MHz) multi-band operations. The low-profile structure of the antenna miniaturizes its size that can be embed the antenna into the mobile equipment. Moreover, the present antenna has the omnidriectional radiation pattern and can be adjusting the branch path to modulate its operation band that satisfies the smart requirements of a modern mobile communication product.

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37

Liu, Ching-Wen, and 劉景文. "Low-profile planar ring-shaped monopole antenna." Thesis, 2003. http://ndltd.ncl.edu.tw/handle/45584013235079201303.

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碩士
國防大學中正理工學院
電子工程研究所
91
In this thesis, several designs of low-profile monopole antennas with omni-directional patterns, multiple operating bands for some special standards or specifications, and a reduced antenna height are presented. The proposed antennas with a largely lowered antenna height are basically constructed by a metallic strip composed of a straight-line section and a ring-shaped section with a tail-slit of 0.5 mm width. Dual-band or tri-band planar monopole antennas are achieved by adding one or two ring-shaped metallic strip(s) with a tail-slit in the inner space of a metallic strip with the same shape and different radii. The total length of each metallic strip, associated with the quarter wavelength of a resonant frequency excited by the metallic strip, can be calculated in the beginning of antenna design process. And, by embedding a suitably selected chip resistor at an appropriate place among ring-shaped metallic strips or adding a properly designed outer arc-shaped metallic strip, impedance matching and bandwidth enhancement of some band mismatched when the chip resistor or the outer arc-shaped metallic strip is absent can be simultaneously obtained. Thus, novel antenna designs for multi-band operation, which are the combinations between GSM and DCS, PCS bands or that between ISM and UNII bands, can be easily implemented.

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38

Ke, Zhi Wen, and 柯智文. "Design of monopole antenna for wireless LAN." Thesis, 1995. http://ndltd.ncl.edu.tw/handle/13579530183771793649.

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39

Yeh, Li-Yu, and 葉秝妤. "Design of Monopole Antenna for Mobile Communications." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/41537682962713408448.

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碩士
南台科技大學
通訊工程研究所
99
Recently, the mobile phone has become a requirement of life. The mobile phone is not already only a communication tool, but also it combines lots of other applications. As the demands for covering bands are increasing, however, designing of antenna is intending toward to small size and compact with multi-band operation. Instead of the traditional exposed antenna, the internal antenna is the current trend since it can place at inner of a handset. For miniaturization of current handsets, internal antenna is easier than exposed antenna. In this thesis, we present two novel antenna designs for mobile phone use. Due to miniature and multifunction requirements of mobile product, we select a monopole antenna as the feed way at first. The antenna can cover GSM900/PCS/DCS/UMTS operation in chapter 2, The printed antenna has been popular for various applications due to low cost and easy to fabrication, low profile and compatible with integrated circuit. However, the WLAN device has become more and more popular for mobile application. For the requirement, we present a monopole antenna design with penta-band operation in chapter 3. Besides, increasing the radiation efficiency, radiation pattern and gain of the miniaturized antenna are discussed in this thesis.

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40

Jian, Jhin-Heng, and 簡智亨. "Designs of 2.4-GHz Monopole Antenna Array." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/54217402149683629278.

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碩士
樹德科技大學
電腦與通訊系碩士班
104
In this study we propose two antenna-array designs, four monopole radiators, with high gain for 2.4-GHz WLAN applications. The first one is with a simple structure, and uses multiple microstrip-line branches to feed the four radiators. The microstrip-line branches is with equal amplitude and in phase or equal phase shifting, that is, each barnching point is like a equal power divider and lengths of microstrip line will be conditionally tuned. By changing the length combination of the microstrip-line branches for shifting the signals’ phase, the radiation pattern and antenna gain of this antenna array can be adjusted. From the experimental result we can find that the radiation of the proposed antenna really can be adjusted and a good antenna gain of about 4.3 to 9 dBi is also demonstrated. In the second antenna array design, a 2.4-GHz WLAN array antenna is implemented by using a 4 by 4 Butler matrix and the four monopole radiators. The 4 by 4 Butler maxtrix has four input ports for connecting source signal and four ouput ports for driving the four monpole radiators. Each input-port signal through the Butler matrix will be seperated into four output signals, with different combination of phase shifting, to drive the monopole radiators and generate a different type of radiation pattern. Therefore, by choosing different input port, a diversity of radiation pattern for the proposed antenna array will be achieved. Besides, size effect of ground plane is also be discussed.

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41

TSENG, BO-FEI, and 曾泊斐. "Analysis of Planer Circular Polarization Monopole Antenna." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/tsvysu.

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碩士
大葉大學
電機工程學系
105
In this research, Different circularly polarized structures are studied on monopole antennas. The circular polarization characteristics are generated by different structures. The first antenna produces a wideband circular polarization characteristic using an offset feed current. The second antenna produces dual-band circular polarization characteristics by an orthogonal structure coupled to the diamond - shaped ground plane. The third antenna produces dual-band circular polarization characteristics using an asymmetric ground plane and a special structure. Frequency bands in this study include WLAN, WiMAX, LTE, etc. The operable frequency band is based on a reflection coefficient below -10 dB and an axis ratio below 3 dB.

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42

Liang, Yi-chung, and 梁議中. "Ultra-broadband CPW-fed circular monopole antenna." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/67601833182890315268.

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碩士
國立中央大學
電機工程研究所
95
A ultra-broadband, planar, circular monopole antenna (PCMA) fed by coplanar waveguide (CPW) structures is demonstrated. The CPW configuration permits easy integration with the uniplanar monolithic integrated circuits/monolithic microwave integrated circuits. Two modifications on the CPW ground plane are applied to improve the impedance bandwidth and radiation characteristics of the CPW-fed PCMA. First, the edges around the circular monopole are tapered to drastically increase the impedance bandwidth. Plus, the antenna gain is increased at the lower frequencies of the band. Second, the tapered edges are corrugated with rectangular gratings to significantly improve the radiation patterns, particularly at the frequencies around the higher band edge. The demonstrated CPW-fed PCMA features an over 151% VSWR=2 fractional bandwidth and satisfactory radiation characteristics over the whole band.

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43

Wu, Cheng-Hsun, and 吳政勳. "UWB Monopole Antenna Having Band-Notched Frequency." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/91331865541039601311.

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碩士
義守大學
電子工程學系碩士班
95
In this thesis, three kinds of ultra wideband (UWB) monopole antennas having band-notched frequency were proposed. First, a printed circular disc monopole antenna with a half ring slot having frequency band-notch characteristic was presented. By etching a slot in the UWB monopole antenna, a notch frequency can be operated. The etched slot can control the notch frequency and bandwidth of the antenna. Second, a printed monopole antenna fed by coplanar waveguide loading split-ring resonators (SRRs) was proposed. SRR loaded CPW structure can achieve a stopband. Notch frequency and attenuation can be controlled by tuning the size and stages of SRR. Finally, we present a printed monopole antenna fed by microstrip lines loading complementary split-ring resonators (CSRRs). For improving attenuation of notch frequency, it can be seen that the performance at high frequency band is improved with the extra patches. Moreover, CSRR stages are decreased with extra patches.

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44

Chen, Pei-Wen, and 陳姵妏. "A V-Shaped Circularly Polarized Monopole Antenna." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/91914493608976082208.

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碩士
大同大學
通訊工程研究所
100
This thesis presents a broadband circularly polarized antenna. The antenna is a V-shaped monopole fed by a microstrip line. The V-shaped design is modified from a reference antenna which contains a vertical and a horizontal arm fed by a microstrip line. By tuning the angle between the two arms, a critical angle yielding a broadband circularly polarized wave can be found. To improve the overlapped return-loss and axial-ratio bandwidth, a slit is cut on the ground plane. It is measured that the return-loss bandwidth is 23% and the axial-ratio bandwidth is 30%.

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45

Huang, Chien-Rung, and 黃建榮. "Compact leaky-wave antenna and dual-band circularly polarized slotted monopole antenna." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/91288063850864701112.

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碩士
國立交通大學
電信工程研究所
100
This thesis consists of two parts：1. Using split ring resonators to suppress the side-lobe level of the tapered compact leaky wave antenna. And 2. Using the structures of slots to excite dual-band circularly polarization in monopole antenna. In the first part, we demonstrate two types of suppressing the reflection wave of the leaky wave antenna. The first structure is to put the split ring resonators at the open end of the leaky wave antenna, and the split ring resonators can generate stop-band to suppress the side-lobe level efficiently. The second structure is to etch the split ring resonators in the ground plane, and the reflected wave will couple to the split ring resonators and be trapped. Thus it can be seen that we can use split ring resonators not only to suppress the side-lobe but also to reduce the length of the leaky wave antenna. In the second part, a dual-band circularly polarized monopole antenna using structures of slots will be introduced. The main structure of the monopole antenna is a circular strip and we add a circular patch at the end of the strip. In the ground plane, we etch a L-shaped slot, and this slot play an important role of exciting the circular polarization not only at the lower band but also at the upper band. The most important is that we can choose the different length of the L-shaped slot to operate on the frequency band what we want. On the other hand, we also add two notches at the antenna, and these two notches can adjust the operating frequency band of circular polarization at the upper band. From the above, we can use these simple structures to get circular polarizations.

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46

Elfergani, Issa T., Abubakar S. Hussaini, Mohammed S. Bin-Melha, Raed A. Abd-Alhameed, Chan H. See, M. M. Abusitta, and Jonathan Rodriguez. "Compact design of tuneable band-notched monopole wideband antenna." 2013. http://hdl.handle.net/10454/9646.

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47

Kao, Ping-Chi, and 高鈵騏. "Designs of CPW-fed Monopole Antennas." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/ufdst6.

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碩士
國立虎尾科技大學
光電與材料科技研究所
94
In recent years, the fast development of the wireless communication network has already provided much convenience to human being’s livings. The size and radiation characteristic of an antenna embedded in a wireless communication network will thus apparently affect the transceiving efficiency of the communication devices. Therefore, design of an antenna with suitable operating band, sufficient bandwidth, compact size, simple structure, and easy implementation for improving the mobility of a wireless communication device becomes the purpose of this study. The subject of this thesis is design of planar printed antennas for application to wireless communication systems. Two feed techniques of coplanar waveguide（CPW）feed and probe feed are utilized in this research to design three CPW-fed antennas with different impedance characteristics and one probe-fed antenna with circular-polarization characteristic. These proposed antenna designs include（1）a CPW-fed inverted triangular patch antenna for ultra-wideband operation（2）a CPW-fed inverted triangular patch antenna with a frequency band notch function for ultra-wideband operation（3）a compact CPW-fed dual folded-strip monopole antenna for 5.8 GHz RFID application, and（4）a square slotted patch antenna for circular polarization. The theoretical simulation, implementation of antenna prototypes, and measurement of antenna characteristics including impedance bandwidth, radiation patterns, and antenna gain, are all detailedly described and discussed in this thesis.

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48

Lai, Chen-Shian, and 賴辰銜. "Planar Ultra Wide Band Miniature Monopole Antenna Designs." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/68714432558127636772.

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碩士
淡江大學
電機工程學系碩士班
93
The goal of this thesis is to design a miniature fully-planar antenna that satisfies for UWB (3.1GHz~10.6GHz) released by the FCC. Most of the planar monopoles reside on a large orthogonal ground plane, and thus the antennas are not fully planar structures.. The fully planar coplanar waveguide-fed or microstrip-fed UWB monopole antennas have attracted the attention of many researchers. None of them has both the impedance bandwidth and radiation bandwidth covering the UWB simultaneously. In this study, the UWB antennas are fabricated on an FR4 board of thickness 0.8mm, for which the relative dielectric constant 4.4 is used for design. In this paper, the miniature ultra wideband (UWB) fully-planar monopole antennas fed by microstrip line are investigated in order to take full advantages of the planar antenna structure, such as the light weight, small size, low cost, conformal and ease of integration with the microwave networks. The empirical formula is employed to determine the initial size of a square monopole, by which the influences of the dimensions upon the reflection coefficient are investigated. It is found that the reflection coefficient is very sensitive to the gap. It is thus proposed to change the shape and size of the gap between the monopole and the ground in order to achieve the goal of miniature wideband antenna. The optimized results show that the radiation patterns in the E plane and the omni-directional characteristic in the H-plane are improved.

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49

Li, Chung-Huan, and 李仲桓. "Study of the microstrip-fed printed monopole antenna." Thesis, 2004. http://ndltd.ncl.edu.tw/handle/73927389480336454152.

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碩士
國立臺灣科技大學
電子工程系
92
The microstrip-fed printed monopole antenna was studied in this thesis in many aspects. Since the physical size of portable communication devices is reduced greatly in recent decades, the ground plane of the products also has to be miniaturized. Besides, it is usually placed in parallel to the monopole in recent applications. This, in turn, will affect the characteristics of regular monopole antenna significantly as well. Since the electrical size of the ground plane is too small to be treated as a ’’ground”, the ground plane should be regarded as a radiator. As a result, it combines with the monopole radiator as an asymmetric dipole antenna. Besides, the feeding structure, namely microstrip-fed, causes the antenna to be as a printed sleeve dipole. This would vary the input impedance with no influence in radiation pattern. The effect of the rectangular ground plane on input impedance and radiation pattern would be discussed in detail. The antenna is an asymmetric dipole and the geometry of the ground plane distorts the pattern dramatically. In particular, the altered current distribution that affects the pattern was different from that of asymmetric slender dipole. In addition, a simple approximation method of resonant resistance estimation with the experiment figure was introduced. On the other hand, the ground plane would induce the other resonance and this could broaden the matching bandwidth efficiently. On the other hand, since the monopole is bent and placed at the side of ground plane for miniaturization in current applications, two practical topics relative to the monopole radiator of the antenna are discussed in this thesis. There include the effect of both monopole setup location shifting and bending on input impedance and radiation pattern of the microstrip-fed printed monopole antenna. Besides, the effect of the substrate was also discussed briefly.

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50

Yang, Shu-Wei, and 楊書維. "Inset Feeding Configuration for A DTV Monopole Antenna." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/83cg8z.

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碩士
大同大學
通訊工程研究所
95
In the thesis, a DTV (Digital television) monopole antenna with an inset feeding configuration is proposed. This monopole antenna has to satisfy the frequency band which is used by DTV (470 MHz to 806 MHz). Therefore, it connects a patch with inset feeding configuration. The goal of wideband is achieved to efficiently increase the impedance bandwidth by appropriating tuning the configuration. In addition, after achieving the above goal, integrate a rectangle metallic plane in back of FR4 without influencing the radiating pattern of the band of DTV. Then, using the method of coupling excites the current which is on the rectangle metallic plane. Additionally, the length, width and position of the rectangle metallic plane to make the retune loss of 2.4 GHz to 2.484 GHz lower than -10 dB, which conforms the using band of WLAN.

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Dissertations / Theses on the topic 'Monopolar antenna'

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