Dissertations / Theses on the topic 'Microstrip patch antenna'
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Lai, Hau Wah. "Wideband meandering probe-fed patch antenna /." access full-text access abstract and table of contents, 2005. http://libweb.cityu.edu.hk/cgi-bin/ezdb/thesis.pl?phd-ee-b19887383a.pdf.
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Thesis (Ph. D.)--City University of Hong Kong, 2005."Submitted to Department of Electronic Engineering in partial fulfillment of the requirements for the degree of Doctor of Philosophy." Includes bibliographical references (leaves 144-153).
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Chiu, Chi Yuk. "Impedance bandwidth broadening techniques for small patch antennas /." access full-text access abstract and table of contents, 2005. http://libweb.cityu.edu.hk/cgi-bin/ezdb/thesis.pl?phd-ee-b19887796a.pdf.
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Thesis (Ph.D.)--City University of Hong Kong, 2005."Submitted to Department of Electronic Engineering in partial fulfillment of the requirements for the degree of Doctor of Philosophy" Includes bibliographical references (leaves 152-162)
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Okuducu, Yusuf. "Dual Band Microstrip Patch Antenna Structures." Master's thesis, METU, 2005. http://etd.lib.metu.edu.tr/upload/2/12606859/index.pdf.
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Wideband and dual band stacked microstrip patch antennas are investigated for the new wideband and dual band applications in the area of telecommunications. In this thesis, aperture-coupled stacked patch antennas are used to increase the bandwidth of the microstrip patch antenna. By this technique, antennas with 51% bandwidth at 6.1 GHz and 43% bandwidth at 8 GHz satisfying S11<-15 dB are designed, manufactured and measured. A dual-band aperture coupled stacked microstrip patch antenna operating at 1.8 GHz with 3.8% bandwidth and at 2.4 GHz with 1.6% bandwidth is designed, produced and measured for mobile phone and WLAN applications. In addition, an aperture coupled stacked microstrip patch antenna which operates at PCS frequencies in 1.7-1.95 GHz band is designed. Dual and circularly polarized stacked aperture coupled microstrip patch antennas are also investigated. A triple band dual polarized aperture coupled stacked microstrip patch antenna is designed to operate at 900 MHz, at 1.21 GHZ and at 2.15 GHz. Mutual coupling between aperture coupled stacked microstrip patch antennas are examined and compared with the coupling of aperture coupled microstrip patch antennas
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Li, Pei. "Novel wideband dual-frequency L-probe fed patch antenna and array /." access abstract and table of contents access full-text, 2006. http://libweb.cityu.edu.hk/cgi-bin/ezdb/thesis.pl?phd-ee-b21471447a.pdf.
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Thesis (Ph.D.)--City University of Hong Kong, 2006."Submitted to Department of Electronic Engineering in partial fulfillment of the requirements for the degree of Doctor of Philosophy" Includes bibliographical references (leaves 179-189)
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Revankar, U. K. "Three-Layer Electromagnetically Coupled Circular Microstrip Antennas." Thesis, Indian Institute of Science, 1995. https://etd.iisc.ac.in/handle/2005/241.
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Presented in this thesis are the following experimental and theoretical investigations carried out on the three-layer electromagnetically coupled (EMC) circular microstrip antennas and their arrays.
1.Three-Layer EMC Circular Microstrip Antenna
A three-layer EMC circular microstrip antenna consists of a probe-fed circular microstrip patch having two parasitically excited circular microstrip patches (without ground planes) stacked above it, with air gaps in between successive substrates. In the "inverted" configuration, the parasitic patches are on the lower (nearer to the driven substrate) surface of the substrate.
An exhaustive experimental study of the resonant frequencies, input impedance, impedance bandwidth and radiation characteristics of this antenna, has been carried out for both the "normal" and the "inverted" configurations. Based on this experimental study, the design and optimisation of the antenna have been discussed and experimentally tested. In the S-band, it is found that an impedance bandwidth as high as 20 percent coupled with good patterns, high gain and low cross-polarisation levels, have been obtained.
2.Three-Layer EMC Circular Microstrip Antenna Arrays
Experimental work has also been carried out on linear arrays of three-layer EMC circular microstrip antennas.
The design of a linear array both in the E- and H- planes, of the three-layer microstrip antennas in their "normal" as well as "inverted" configurations, has been discussed and realisation carried out. Impedance bandwidths of the arrays have been experimentally found to be the same as that of the three-layer antenna element High gain and good pattern shape with sidelobes as well as cross-polarisation levels better than -20 dB through a scan angle of 40°, have been realised.
A study of the mutual coupling between two-layer as well as three-layer EMC circular patch elements has also been carried out for the useful range of interelement spacings.
3.Theoretical Analysis of Resonant Frequencies of Multilayer Patch Structures
Theoretical investigations have been carried out on the resonance properties of single-layer and multilayer EMC patch structures employing the full-wave analysis based on spectral domain immittance approach. The impedance Green's functions for all these structures have been derived from the combination of equivalent transverse transmission lines concept Galerkin's method is employed in the spectral (Hankel) transform domain where two sets of disk current expansions are used for obtaining die characteristic equation. By solving the characteristic equation, the resonant frequencies are obtained for various values of the parameters of the layered antenna.
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Revankar, U. K. "Three-Layer Electromagnetically Coupled Circular Microstrip Antennas." Thesis, Indian Institute of Science, 1995. http://hdl.handle.net/2005/241.
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Presented in this thesis are the following experimental and theoretical investigations carried out on the three-layer electromagnetically coupled (EMC) circular microstrip antennas and their arrays.
1.Three-Layer EMC Circular Microstrip Antenna
A three-layer EMC circular microstrip antenna consists of a probe-fed circular microstrip patch having two parasitically excited circular microstrip patches (without ground planes) stacked above it, with air gaps in between successive substrates. In the "inverted" configuration, the parasitic patches are on the lower (nearer to the driven substrate) surface of the substrate.
An exhaustive experimental study of the resonant frequencies, input impedance, impedance bandwidth and radiation characteristics of this antenna, has been carried out for both the "normal" and the "inverted" configurations. Based on this experimental study, the design and optimisation of the antenna have been discussed and experimentally tested. In the S-band, it is found that an impedance bandwidth as high as 20 percent coupled with good patterns, high gain and low cross-polarisation levels, have been obtained.
2.Three-Layer EMC Circular Microstrip Antenna Arrays
Experimental work has also been carried out on linear arrays of three-layer EMC circular microstrip antennas.
The design of a linear array both in the E- and H- planes, of the three-layer microstrip antennas in their "normal" as well as "inverted" configurations, has been discussed and realisation carried out. Impedance bandwidths of the arrays have been experimentally found to be the same as that of the three-layer antenna element High gain and good pattern shape with sidelobes as well as cross-polarisation levels better than -20 dB through a scan angle of 40°, have been realised.
A study of the mutual coupling between two-layer as well as three-layer EMC circular patch elements has also been carried out for the useful range of interelement spacings.
3.Theoretical Analysis of Resonant Frequencies of Multilayer Patch Structures
Theoretical investigations have been carried out on the resonance properties of single-layer and multilayer EMC patch structures employing the full-wave analysis based on spectral domain immittance approach. The impedance Green's functions for all these structures have been derived from the combination of equivalent transverse transmission lines concept Galerkin's method is employed in the spectral (Hankel) transform domain where two sets of disk current expansions are used for obtaining die characteristic equation. By solving the characteristic equation, the resonant frequencies are obtained for various values of the parameters of the layered antenna.
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Smith, Christopher Brian. "Wideband dual-linear polarized microstrip patch antenna." [College Station, Tex. : Texas A&M University, 2008. http://hdl.handle.net/1969.1/ETD-TAMU-3162.
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Belentepe, Bilge. "Electromagnetically coupled microstrip patch antenna array design." Thesis, University of Surrey, 1993. http://epubs.surrey.ac.uk/842825/.
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This work is an effort to investigate and derive a simple equivalent circuit model to represent an electromagnetically coupled microstrip patch antenna. This provides a simple approach to the complicated electromagnetic coupling behaviour in the patch. A simplified theory based on the broadside coupled line and improved transmission line theories is developed to derive the equivalent circuit of EM coupled patch antenna. The design parameters are determined from the above mentioned theory. Computer programs are developed to provide a practical design of such antennas without involving complicated, time consuming, rigorous methods. A number of sample patches are designed, made and tested to verify the theory. These elements are also incorporated into an array to evaluate their performance in an array environment. The impedance and pattern measurements are made for comparison with theoretical results.
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Krier, Peter. "Microstrip patch antennas on gallium arsenide substrates." Thesis, University of Leeds, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.256366.
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Fatthi, Alsager Ahmed. "Design and Analysis of Microstrip Patch Antenna Arrays." Thesis, Högskolan i Borås, Institutionen Ingenjörshögskolan, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:hb:diva-20461.
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The performance and advantages of microstrip patch antennas such as lowweight, low profile, and low cost made them the perfect choice forcommunication systems engineers. They have the capability to integrate withmicrowave circuits and therefore they are very well suited for applications suchas cell devices, WLAN applications, navigation systems and many othersIn this thesis; a compact rectangular patch antennas are designed and tested forGPS devices at 1.57542 GHz, and for a satellite TV signal at 11.843 GHz and11.919 GHz. The final part of this work has been concentrated on studying anarray antenna with two and four elements. The antennas of the design examplesof this work has been manufactured and tested in laboratory.
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Jacmenovic, Dennis, and dennis_jacman@yahoo com au. "Optimisation of Active Microstrip Patch Antennas." RMIT University. Electrical and Computer Engineering, 2004. http://adt.lib.rmit.edu.au/adt/public/adt-VIT20060307.144507.
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This thesis presents a study of impedance optimisation of active microstrip patch antennas to multiple frequency points. A single layered aperture coupled microstrip patch antenna has been optimised to match the source reflection coefficient of a transistor in designing an active antenna. The active aperture coupled microstrip patch antenna was optimised to satisfy Global Positioning System (GPS) frequency specifications. A rudimentary aperture coupled microstrip patch antenna consists of a rectangular antenna element etched on the top surface of two dielectric substrates. The substrates are separated by a ground plane and a microstrip feed is etched on the bottom surface. A rectangular aperture in the ground plane provides coupling between the feed and the antenna element. This type of antenna, which conveniently isolates any circuit at the feed from the antenna element, is suitable for integrated circuit design and is simple to fabricate. An active antenna design directly couples an antenna to an active device, therefore saving real estate and power. This thesis focuses on designing an aperture coupled patch antenna directly coupled to a low noise amplifier as part of the front end of a GPS receiver. In this work an in-house software package, dubbed ACP by its creator Dr Rod Waterhouse, for calculating aperture coupled microstrip patch antenna performance parameters was linked to HP-EEsof, a microwave computer aided design and simulation package by Hewlett-Packard. An ANSI C module in HP-EEsof was written to bind the two packages. This process affords the client the benefit of powerful analysis tools offered in HP-EEsof and the fast analysis of ACP for seamless system design. Moreover, the optimisation algorithms in HP-EEsof were employed to investigate which algorithms are best suited for optimising patch antennas. The active antenna design presented in this study evades an input matching network, which is accomplished by designing the antenna to represent the desired source termination of a transistor. It has been demonstrated that a dual-band microstrip patch antenna can be successfully designed to match the source reflection coefficient, avoiding the need to insert a matching network. Maximum power transfer in electrical circuits is accomplished by matching the impedance between entities, which is generally acheived with the use of a matching network. Passive matching networks employed in amplifier design generally consist of discrete components up to the low GHz frequency range or distributed elements at greater frequencies. The source termination for a low noise amplifier will greatly influence its noise, gain and linearity which is controlled by designing a suitable input matching network. Ten diverse search methods offered in HP-EEsof were used to optimise an active aperture coupled microstrip patch antenna. This study has shown that the algorithms based on the randomised search techniques and the Genetic algorithm provide the most robust performance. The optimisation results were used to design an active dual-band antenna.
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Tasoglu, Ali Ozgur. "Analysis And Design Of Cylindrically Conformal Microstrip Antennas." Master's thesis, METU, 2011. http://etd.lib.metu.edu.tr/upload/12613441/index.pdf.
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Cylindrically conformal microstrip antennas are investigated. Two different structures, namely proximity coupled and E-shaped microstrip antennas are analyzed and information about the design parameters is obtained by means of parametric study. With these structures, cylindrical arrays, having omnidirectional radiation in the circumferential plane of the cylinder, are designed. Proximity coupled cylindrical arrays operate in the 2.3-2.4 GHz aeronautical telemetry band with approximately 4% bandwidth. On the other hand, more than 30% bandwidth is obtained by E-Shaped cylindrical array
antenna structure, which also includes the commercial telemetry band. In order to verify the simulation method, a fabricated antenna in literature is simulated and acceptable agreement with simulation and fabrication results obtained.
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Khan, Raja Sheharyar, and Muhammad Ishfaq. "A Compact Microstrip Patch Antenna for LTE Applications." Thesis, Linnéuniversitetet, Institutionen för fysik och elektroteknik (IFE), 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:lnu:diva-24505.
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A compact multiband antennas for Long Term Evolution (LTE) applications is a challenge. Both the frequencies of new wireless technologies and new frequency bands must be covered. The lower end of the 0.7- 3.5 GHz band is especially difficult to handle for miniaturized terminal devices. A single layer, line-feed rectangular microstrip patch antenna is small enough for the LTE handsets. Our project proposes size reduction and bandwidth enhancement through adapted feeding techniques. By means of slits the return loss and gain can be optimized with the aid of HFSS (High Frequency Structure Simulator).
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Lanka, Subrahmanya Vivekananda. "Pattern Analysis of “The Rectangular Microstrip Patch Antenna”." Thesis, Högskolan i Borås, Institutionen Ingenjörshögskolan, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:hb:diva-19564.
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In the recent years the development in communication systems requires the development of low cost, minimal weight, low profile antennas that are capable of maintaining high performance over a wide spectrum of frequencies. This technological trend has focused much effort into the design of a Microstrip patch antenna. In this work, the patter of two designs of a Microstrip patch antenna have been analyzed and studied.Design1 (LxWxH: 23mm x 30mm x 1.5mm) with a dielectric constant of 9.8(alumina) at 2.1GHz and Design2 (LxWxH: 47mm x 31mm x 1.59mm) with a dielectric constant 2.32 at 2.1GHz.These two designs have been compared with other two from the literature by using SonnetLite software and IE3D from Zeland.After the design when we compared the results of the Design1 and Design2, Design2 has the highest Antenna Efficiency (the configuration can be seen above) of 80%. With this we suggest the best configuration that can be used in practice would be Design 2.A rigorous analysis of the problem begins with the application of the equivalence principle that introduces the unknown electric and magnetic surface current densities on the dielectric surface. The formulation of the radiation problems is based on the combined field integral equations coupled to the Method of Moments (MoM) as a numerical solution of the integral equations.
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Erel, Mahmut. "Design of microstrip patch antenna for the NPSAT1." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2002. http://library.nps.navy.mil/uhtbin/hyperion-image/02Dec%5FErel.pdf.
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Thesis (M.S. in Electrical Engineering)--Naval Postgraduate School, December 2002.Thesis advisor(s): Jovan E. Lebaric, Richard W. Adler. Includes bibliographical references (p. 61). Also available online.
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PARTHASARATHY, KRISHNAN V. "MUTUAL COUPLING IN PATCH ANTENNA ARRAYS." University of Cincinnati / OhioLINK, 2006. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1148325728.
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Khan, Jahanzeb. "Design of Microstrip Patch Antenna on Liquid Crystal Polymer (LCP) for Applications at 70GHz." Thesis, University of Gävle, Department of Technology and Built Environment, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:hig:diva-807.
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The demand of small size electronic systems has been increasing for several decades. The physical size of systems is reduced due to advancements in integrated circuits. With reduction in size of electronic systems, there is also an increasing demand of small and low cost antennas. Patch antennas are one of the most attractive antennas for integrated RF front end systems due to their compatibility with microwave integrated circuits. To fulfil the demand of integrated RF front end systems, a design of microstrip patch antenna with optimum performance at 70GHz is investigated. The procedure could be extended to design other planar antennas that act in a similar way.
In this work, three different design methods to design patch antennas for applications at 70GHz are investigated that include use of analytical models, numerical optimization, and numerical variation of dimensions. Analytical models provide a basic understanding of the operation of a patch antenna and they also provide approximate dimensions of a patch antenna for a targeted frequency without using numerical simulations. However, as the operating frequencies of RF systems reach mm-wave frequencies, we expect that the accuracy of analytical models become less accurate. For example, the excitation of substrate modes and effect of ground size are not predicted in simple analytical models.
Due to these expected limitations of the analytical design methods, the accuracy of these models is investigated by numerical electromagnetic field simulations. In this work, CST Microwave Studio Transient Solver is used for that purpose. In order to make sure that the appropriate settings of the solver are applied, the simulation settings such as mesh density, boundary conditions and the port dimensions are investigated. The simulation settings may affect computation time and convergence of the results. Here, in this work, the accuracy of the simulator for a specific design of inset feed rectangular patch antenna is verified. The patch dimensions obtained from analytical calculations are optimized at 70GHz by using the optimizer of the transient solver. The patch dimensions obtained from optimizer are verified by varying the patch dimensions in equidistant steps around the found result of the optimizer.
In a rectangular microstrip patch antenna design, the use of a width of 1.5 times the length is an approximate rule of thumb [1] for low dielectric constant substrates. It is also investigated how the performance properties of a microstrip patch antenna are affected by varying the width to length ratio of the patch. There are occasions where a different ratio is required because of space limitations, or to change the input impedance. The patch designs having various width to length ratios were optimized with the feed location.
The analytically calculated dimensions provided good initial values of the rectangular patch antenna for further optimization using more accurate techniques. The design have been optimized at 70GHz for the investigated mesh density, boundary conditions and the port dimensions. The numerical variation of dimensions is found to be most reliable among the investigated design methods but it is more complicated with many parameters.
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Yildirim, Meltem. "Design Of Dual Polarized Wideband Microstrip Antennas." Master's thesis, METU, 2010. http://etd.lib.metu.edu.tr/upload/12612023/index.pdf.
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In this thesis, a wideband dual polarized microstrip antenna is designed, manufactured and measured. Slot coupled patch antenna structure is considered in order to achieve the wideband characteristic. Although rectangular shaped slot coupled patch antennas are widely used in most of the applications, their utilization in dual polarized antenna structures is not feasible due to space limitations regarding the positioning of two separate coupling slots for each polarization. For a rectangular slot, the parameter that affects the amount of coupling is the slot length. On the other hand when a H-shaped slot is considered, both the length of the center arm and the length of the side legs determine the coupling efficiency. This flexibility about the optimization parameters of the H-shaped slot makes it possible to position the two coupling slots within the boundaries of the patch antenna. Therefore, H-shaped slot coupled patch antennas are studied in this thesis. In order to investigate the effects of slot and antenna dimensions on the radiation characteristics of the antenna, a parametric study is performed by analyzing the antenna structure with a planar electromagnetic field simulation software (Ansoft Designer). By the help of the experience gained through this parametric study, a dual polarized patch antenna that can be used at the base station of a cellular system (DCS: 1710&ndash1880 MHz) is designed. Before manufacturing the antenna, dimensions of the antenna are re-tuned by considering a finite sized ground plane in the simulations. Finally, the antenna is manufactured and measured. An acceptable agreement is obtained between the measurement and the simulation results.
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Maki, Pamela Ruth. "A dual circularly polarized single element microstrip patch antenna." Thesis, Stellenbosch : Stellenbosch University, 2004. http://hdl.handle.net/10019.1/49818.
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Thesis (MScEng)--University of Stellenbosch, 2004.ENGLISH ABSTRACT: This thesis discusses the design of a dual circularly polarized single element antenna with special emphasis on achieving a wide bandwidth and high polarization isolation. The aim of the study is to produce an antenna for transmission of colour video signals between a ground station and a low earth orbit satellite. Microstrip patch antennas are suitable for satellite applications because they are light weight, conformal and have a thin profile. However, the antennas' inherent naITOW bandwidth is one of their major drawbacks. The aperture coupled microstrip patch antenna boasts of a much-improved bandwidth over the traditional single layer microstrip antenna and the freedom of using separate substrates for the patch and the feeding network. Hence the designed single element antenna is aperture coupled. To achieve dual circular polarization with good polarization purity, the antenna had a crossed slot aperture with a balanced feed. The feed network was designed on a single layer. The design was executed in two steps using IE3D moment of methods simulation software: design of the radiating part, and design of the feed part. Each part was simulated and optimized on its own before the two were combined, simulated and optimized again. Parameters used in the antenna optimization were: the substrates' thicknesses and dielectric constants, patch and aperture dimensions, and the feed line width and offset. The designed antenna was built and measured. Initial measurements of S-parameters yielded unacceptable results, especially for S22 and S21, and so an investigation into the matter was conducted. That led to the sizes of the feed and reflector planes being extended. Absorbing material was used between the parallel feed and reflector planes because some power was, to a lesser extent, still escaping, due to the fact that the planes were fmite. Measurement results demonstrated reasonable agreement with the simulation. The final antenna had a reflection coefficient of less than -10 dB for the entire operating band of 400 MHz centred on 3 GHz, an isolation of approximately -15 dB in the operating band and a gain of 2 dBi and I dBi for Ports 1 and 2, respectively, at 3 GHz. These results, especially the gain, are influenced by the back radiation and the finite sizes of the feed and reflector planes. It is therefore recommended that an enclosed cavity be used at the back of the antenna and a 'dogbone' aperture be used to minimize back radiation.
AFRIKAANSE OPSOMMING: Die tesis omskryf die ontwerp van 'n tweevoudige sikuler gepolariseerde enkel-element antenne met spesiale klem op wye bandwydte en hoe polariserings isolasie. Die doel van hierdie studie is om 'n antenne vir uitsending van kleur video seine tussen 'n grond stasie en 'n omnentelingsatelliet daar te stel. Mikrostrook plakantennes is gepas vir satelliet toepassings weens hulle ligte gewig en dun profiel. Die antenne se gepaardgaande nou bandwydte is egter een van hulle grootste nadele. Die gleufgekoppelde mikrostrook plakantenne gee egter 'n baie beter bandwydte as die tradisionele enkellaag mikrostrook plakantenne asook die vryheid om verskillende substrate vir die plak en die voernetwerkte gebruik. Vir hierdie redes daar besluit om die enkel-element antenne sleufgekoppeld te maak. Om tweevoudige sikuler gepolariseerde met goeie polarisasie suiwerheid te kry, moes 'n kruisvonnige gleuf met 'n gebalanseerde voer ontwerp word. Die voernetwerk was op 'n enkellaag ontwerp. Die ontwerp was in twee fases in IE3D momentmetode simulasie sagteware gedoen: ontwerp van die stralings gedeelte, en ontwerp van die voer gedeelte. Elke gedeelte word afsonderlik gesimuleer en geoptimiseer voordat die twee saam gesimuleer en geoptimiseer word. Parameters wat gebruik word in die antenne optimiseering is: dikte van substraat en dielektriese konstante, plak en gleuf grootes, en voer lynwydte en afwyking. Die ontwerpde antenne is gebou en gemeet. Aanvanklike metings van S-parameters het onaanvaarbare resultate gel ewer, vera I vir S22 en S21,dus is daar besluit om die redes daarvoor te ondersoek. Dit het daartoe gelei dat die voer- en reflector vlakte groter gemmak is. Absorbeer material is tussen die parallel voer- en reflector vlakke gebruik aangesien steeds drywing verloor is weens die eindige vlakke. Meting resultate het taarnlike goed met die simulasies vertoon. Die finale antenne het 'n weerkaatskoeffisient laer as -10 dB getoon vir die volle bandwydte van 400 MHz gesentreerd rondom 3 GHz, 'n isolasie van ongeveer -15 dB in die bandwydte en 'n aanwins van 2 dBi en I dBi vir onderskeidelik Poorte I en 2 by 3 GHz. Hierdie resultate veral die aanwins is deur die straling na agter beinvloed en die eindige grootes van die voer- en reflector vlakke. Dit word om hierdie rede dus voorgestel dat 'n geslote holte aan die rugkant van die antenne gebruik word en dat 'n "dogbone" gleuf gebruik word om straling na agter te minimeer.
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Hategekimana, Bayezi. "A Wideband Stacked Microstrip Patch Antenna for Telemetry Applications." International Foundation for Telemetering, 2010. http://hdl.handle.net/10150/604303.
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ITC/USA 2010 Conference Proceedings / The Forty-Sixth Annual International Telemetering Conference and Technical Exhibition / October 25-28, 2010 / Town and Country Resort & Convention Center, San Diego, CaliforniaThis research article reports a design of a wide band multilayer microstrip patch antenna (MSPA). Positions of a coaxial probe feed to main patch of the multilayer MSPA, widths and lengths of main and parasitic patches, and height of a Rohacell foam layer in the multilayer MSPA were optimized to achieve desired performance in L-band. The work also reports a design of a two-by-two array of multilayer MSPA. We present results on antenna radiation patterns and return loss obtained with full wave finite element simulations with Ansoft HFSS software and measurements with a vector network analyzer.
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Mayhew-Ridgers, Gordon. "Development and modelling of new wideband microstrip patch antennas with capacitive feed probes." Thesis, Pretoria : [s.n.], 2004. http://upetd.up.ac.za/thesis/available/etd-09162004-083016.
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Luther, Justin. "Microstrip Patch Electrically Steerable Parasitic Array Radiators." Doctoral diss., University of Central Florida, 2013. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/5984.
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This dissertation explores the expansion of the Electrically Steerable Parasitic Array Radiator (ESPAR) technology to arrays using microstrip patch elements. Scanning arrays of two and three closely-coupled rectangular patch elements are presented, which incorporate no phase shifters. These arrays achieve directive radiation patterns and scanning of up to 26° with maintained impedance match. The scanning is effected by tunable reactive loads which are used to control the mutual coupling between the elements, as well as additional loads which compensate to maintain the appropriate resonant frequency. The design incorporates theoretical analysis of the system of coupled antennas with full-wave simulation. A prototype of the three-element array at 1 GHz is fabricated and measured to exhibit a maximum gain of 7.4 dBi with an efficiency of 79.1%. Further, the microstrip ESPAR is thoroughly compared to uniformly-illuminated arrays of similar size.
To satisfy the need for higher directivity antennas with inexpensive electronic scanning, the microstrip ESPAR is then integrated as a subarray. The three-element subcell fabrication is simplified to a single layer with an inverted-Y groove in the ground plane, allowing for DC biasing without the need for the radial biasing stubs or tuning stubs found in the two-layer design. The 1 GHz ESPAR array employs a corporate feed network consisting of a Wilkinson power divider with switchable delay line phase shifts, ring hybrid couplers, and achieves a gain of 12.1 dBi at boresight with &"177;20° scanning and low side lobes. This array successfully illustrates the cost savings associated with ESPAR subarray scanning and the associated reduction in required number of phase shifters in the RF front end.Ph.D.
Doctorate
Electrical Engineering and Computer Science
Engineering and Computer Science
Electrical Engineering
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Ali, Abdulbaset M. M. "Gain enhancement of microstrip patch antenna using dielectric DNG superstrate /." Online version of thesis, 2009. http://hdl.handle.net/1850/11170.
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Elmezughi, Abdurrezagh, and s3089087@student rmit edu au. "Investigation of Methods for Integrating Broadband Microstrip Patch Antennas." RMIT University. Electrical and Computer Engineering, 2009. http://adt.lib.rmit.edu.au/adt/public/adt-VIT20090305.093332.
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The use of the microstrip antenna has grown rapidly for the last two decades, because of the increasing demand for a low profile antenna with small size, low cost, and high performance over a large spectrum of frequencies. However, despite the advantages microstrip antennas provide, a number of technical challenges remain to be solved for microstrip antennas to reach their full potential, particularly if they are to be interfaced with monolithic circuits. The objective of this thesis is to examine novel methods for integrating and constructing broadband microstrip antennas, particularly at high microwave and millimeter wave frequencies where dimensions get very small and fabrication tolerances are critical. The first stage of the thesis investigates techniques to reduce the spurious feed radiation and surface wave generation from edge-fed patch antennas. A technique to reduce the spurious radiation from the edge-fed patch antenna by using a dielectric filled cavity behind the radiating element is explored. From this, a single element edge-fed cavity backed patch antenna was developed. Measured results showed low levels of cross polarization, making it suitable for dual or circular polarization applications. A 2 x 2 edge-fed cavity backed patch antenna array was also developed, which benefited greatly from this new technique due to the extensive feed network required. Furthermore, investigation into edge-fed cavity backed patches on high dielectric materials was also conducted. The measured impedance bandwidth of this edge-fed cavity backed patch is three times greater than the conventional edge-fed patch, and the gain increases to 5.1 dBi compared to 3.6 dBi. Further bandwidth enhancement of the single element edge-fed cavity backed antenna on high dielectric material was achieved by applying the hi-lo substrate structure. The hi-lo substrate structure produced an increase in the bandwidth to 26% from the 1.7% of the single element edge-fed cavity backed patch, while maintaining pattern integrity and radiation efficiency. Next, the development of a flip-chip bonding technique was investigated to enhance the fabrication accuracy and robustness of multilayer antennas on high dielectric materials. This technique was proven through simulation and experiment to provide good impedance and radiation performance via the high accuracy placement of the superstrate layer. The single element flip-chip patch antenna uses a high dielectric constant material for both the base and the patch superstrate, whereas the stacked flip-chip patch again uses a high and low permittivity material combination to achieve efficient wideband performance. Due to the high permittivity feed material, these antennas display the attributes required for integration with MMICs. The measured 10 dB return loss bandwidth of the single element was 4% with a gain of 4.6 dBi, whereas the stacked flip-chip patch showed very broadband performance, with a bandwidth of 23% with a gain of 8.5 dBi. The high accuracy placement and rigid attachment of the upper superstrat e layer via the flip-chip bonding technique also enables these antennas to be scaled up to millimeter-wave operational frequencies. The final section of this thesis is focused on developing a fabrication technique to enable the creation of a low permittivity layer at a nominated thickness.
25
Acimovic, Igor. "Improving port isolation in dual-polarized microstrip patch antenna arrays." Thesis, University of Ottawa (Canada), 2006. http://hdl.handle.net/10393/27323.
Full textAbstract:
In this thesis we present the design techniques mitigating the port isolation degradation in dual-polarized microstrip arrays. The advantages of using dual-polarized antennas are the frequency band reuse and simultaneous receive/transmit capability. To fully exploit these advantages the isolation between orthogonally polarized ports must be maximized and radiation cross-polarization minimized.
To prevent the port isolation degradation due to presence of the feed network lines surrounding the radiator the "folded" feed optimized to maximize the port isolation is introduced. The analysis of the port isolation dependence on radiating element positioning and grouping as well as the layout of the non-mirrored sections of the feed network within the array is performed. Based on the design guidelines introduced in this thesis the 4x4 element dual-polarized microstrip patch array was manufactured and port isolation in excess of 40dB was measured over the impedance bandwidth. The effects of excitation amplitude taper and excitation phase progression on port isolation performance of the array are examined and the results presented.
26
Ng, Ming Wah. "TLM modelling of microstrip patch antenna on magnetized ferrite substrate." Thesis, University of London, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.405515.
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Akgun, Erdem. "Millimeter Wave Microstrip Launchers And Antenna Arrays." Master's thesis, METU, 2006. http://etd.lib.metu.edu.tr/upload/12607863/index.pdf.
Full textAbstract:
Coaxial-to-microstrip launcher and microstrip patch array antenna are designed to work at center frequency of 36.85 GHz with a bandwidth higher than 300 MHz. The antenna array design also includes the feeding network distributing the power to each antenna element. The design parameters are defined on this report and optimized by using an Electromagnetic Simulation software program. In order to verify the theoretical results, microstrip patch array antenna is produced as a prototype. Measurements of antenna parameters, electromagnetic field and circuit properties are interpreted to show compliance with theoretical results. The values of deviation between theoretical and experimental results are discussed as a conclusion.
28
Almutawa, Ahmad Tariq. "Log-Periodic Microstrip Patch Antenna Miniaturization Using Artificial Magnetic Conductor Surfaces." Scholar Commons, 2011. http://scholarcommons.usf.edu/etd/2982.
Full textAbstract:
Microstrip patch antennas are attractive for numerous military and commercial applications due to their advantages in terms of low-profile, broadside radiation, low-cost, low-weight and conformability. However, the inherent narrowband performance of patch antennas prohibits their use in systems that demand wideband radiation. To alleviate the issue, an existing approach is to combine multiple patch antennas within a log-periodic array configuration. These log-periodic patch antennas (LPMAs) are capable of providing large bandwidths (>50%) with stable broadside radiation patterns. However, they suffer from electrically large sizes. Therefore, their miniaturization without degrading the bandwidth performance holds promise for extending their use in applications that demand conformal and wideband installations.
In recent years, electromagnetic band gap structures have been proposed to enhance the radiation performances of printed antennas. These engineered surfaces consist of a periodic arrangement of unit cells having specific metallization patterns. At particular frequencies, they provide a zero-degree phase shift for reflected plane waves and effectively act as high impedance surfaces. Since, their band-limited electromagnetic field behavior is quite similar to a hypothetical magnetic conductor; they are also referred to as artificial magnetic conductors (AMCs). AMC structures were shown to allow lower antenna profile, larger bandwidth, higher gain, and good unidirectional radiation by alleviating the field cancellation effects observed in ground plane backed antenna configurations.
Previous research studies have already demonstrated that microstrip patch antennas can enjoy significant size reductions when placed above the AMC surfaces. This project, for the first time, investigates the application of AMCs to LPMA configurations. Specifically, the goal is to reduce the LPMA size while retaining its highly desired large bandwidth performance. To accomplish this, we employ various AMC surface configurations (e.g. uniform, log-periodic) under traditional LPMAs and investigate their performance in terms of miniaturization, bandwidth, gain, and radiation patterns.
29
Gupta, Sanjeev. "Tracking antenna architectures based on an integrated mixer microstrip patch array." Thesis, Queen's University Belfast, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.247349.
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Jackson, Ronald Edward Ramadoss Ramesh. "MEMS based tunable microstrip patch antenna fabricated using printed circuit processing techniques." Auburn, Ala., 2006. http://repo.lib.auburn.edu/2006%20Summer/Theses/JACKSON_RONALD_51.pdf.
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31
Sener, Goker. "Analysis And Design Of Microstrip Patch Antennas With Arbitrary Slot Shapes." Phd thesis, METU, 2011. http://etd.lib.metu.edu.tr/upload/12613161/index.pdf.
Full textAbstract:
A new method is proposed that provides simple and effcient design and analysis algorithm for microstrip antennas with arbitrary patch shapes. The proposed procedure uses the mutiport network model (MNM) where the antenna is considered as a cavity bounded by perfect electric conductors on the top and the bottom surfaces and perfect magnetic conductor on the side surfaces. Ports are defined along the periphery of the patch, and the impedance
matrix representing the voltage induced at one port due to a current source at another port, is obtained through the use of the 2-D Green&rsquos function corresponding to the cavity. For the MNM analysis of patches with irregular shapes such as slotted structures, the segmentation/desegmentation methods are utilized since the Green&rsquo
s function expressions are available only for regularly shaped cavities. To speed up the analysis and to develop a design procedure, vector Pade approximation is used in order to approximate the antenna impedance matrix as a rational function of two polynomials. When the approximation is performed with respect to frequency, the roots of the polynomial at the denominator provides the resonant frequencies of the antenna. The design algorithm is applicable when the approximation variable is changed to one of the dimensions of the patch that need to be optimized. Because for this case, the roots of the denominator polynomial correspond to optimum dimensions of the antenna where it resonates.
32
Yee, Steven C. (Steven Christopher) 1989. "A frequency reconfigurable circularly polarized microstrip patch antenna using liquid metal microswitches." Thesis, Massachusetts Institute of Technology, 2013. http://hdl.handle.net/1721.1/82359.
Full textAbstract:
Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2013.Cataloged from PDF version of thesis.
Includes bibliographical references (p. 78-80).
Reconfigurable antennas with adaptable frequency, pattern, and polarization offer flexibility and size reduction for wireless systems that must increasingly execute multiple missions with less volume. These antennas will also complement anticipated cognitive radio systems, which promise more efficient use of the electromagnetic spectrum. Microscale liquid metal switches are proposed to overcome the series loss, mechanical fatigue, and limited power handling reliability of common methods of antenna reconfiguration such as semiconductor diodes and microelectromechanical switches. The proposed microswitches consist of mercury droplets that selectively connect solid metal traces. Both fluidic and electrostatic switch actuation mechanisms are investigated, and an electrostatic switch is demonstrated. Electrostatically actuated switches are designed into a compact single-feed patch antenna configurable between two communication frequency bands and a GPS band with different circular polarizations. The antenna topology is based on a corner truncated square patch with switched sets of extensions to achieve resonant frequency and axial ratio control. Measurements of reconfigurable prototypes demonstrate frequency and polarization configurability in good agreement with full-wave simulations. The proposed reconfiguration mechanism is compared to other methods, and future directions for the integration of microfluidics in reconfigurable radio frequency systems are proposed.
by Steven Christopher Yee.
S.M.
33
Staffan, Paul. "Design of an ultra-wideband microstrip antenna array with low size, weight and power." Wright State University / OhioLINK, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=wright1578437280799995.
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34
Kawser, Mohammad Tawhid. "Investigation of a Novel Dual Band Microstrip/Waveguide Hybrid Antenna Element." Thesis, Virginia Tech, 2005. http://hdl.handle.net/10919/33660.
Full textAbstract:
Microstrip antennas are low in profile, light in weight, conformable in structure and are now developed for many applications. The main difficulty of the microstrip antenna is its narrow bandwidth. Several modern applications like satellite communications, remote sensing and multi-function radar systems will find it useful if there is dual band antenna operating from a single aperture. Some applications require covering both transmitting and receiving frequency bands which are spaced apart. Providing multiple antennas to handle multiple frequencies and polarizations becomes especially difficult if the available space is limited as with airborne platforms and submarine periscopes.
Dual band operation can be realized from a single feed using slot loaded or stacked microstrip antenna or two separately fed antennas sharing a common aperture. The former design, when used in arrays, has certain limitations like complicated beam forming or diplexing network and difficulty to realize good radiation patterns at both the bands. The second technique provides more flexibility with separate feed system as beams in each frequency band can be controlled independently. Another desirable feature of a dual band antenna is easy adjustability of upper and lower frequency bands.
This thesis presents investigation of a new dual band antenna, which is a hybrid of microstrip and waveguide radiating elements. The low band radiator is a Shorted Annular Ring (SAR) microstrip antenna and the high band radiator is an aperture antenna. The hybrid antenna is realized by forming a waveguide radiator in the shorted region of the SAR microstrip antenna. It is shown that the upper to lower frequency ratio can be controlled by the proper choice of various dimensions and dielectric material. Operation in both linear and circular polarization is possible in either band. Moreover, both broadside and conical beams can be generated in either band from this antenna element.
Finite Element Method based software, HFSS and Method of Moments based software, FEKO were employed to perform parametric studies of the proposed dual band antenna. The antenna was not tested physically. Therefore, in most cases, both HFSS and FEKO were employed to corroborate the simulation results.Master of Science
35
Khattak, Muhammad Kamran, Osama Siddique, and Waqar Ahmed. "Design and Simulation of Microstrip Phase Array Antenna using ADS." Thesis, Linnéuniversitetet, Institutionen för datavetenskap, fysik och matematik, DFM, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:lnu:diva-11715.
Full textAbstract:
The aim of this project is to design a microstrip phase array antenna in ADS (Advance Design System) Momentum. The resonant frequency of which is 10 GHz. Two circular patches with a radius of 5.83 mm each are used in designing the array antenna. RT-DURROID 5880 is used as a substrate for this microstrip patch array design. These circular patches are excited using coaxial probe feed and transmission lines of particular lengths and widths. These transmission lines perfectly match the impedance of the circular patches. Various parameters, for example the S-parameters, two dimensional and three dimensional radiation patterns, excitation models, gain, directivity and efficiency of the designed antenna are obtained from ADS Momentum.
36
Maia, Hugo Michel C?mara de Azevedo. "Antenas de microfita com patch supercondutor a 212 K." Universidade Federal do Rio Grande do Norte, 2010. http://repositorio.ufrn.br:8080/jspui/handle/123456789/15328.
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Previous issue date: 2010-07-09Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior
This work has as main objective to study the application of microstrip antennas with patch and use of superconducting arrays of planar and linear phase. Was presented a study of the main theories that explain clearly the superconductivity. The BCS theory, Equations of London and the Two Fluid Model are theories that supported the implementation of the superconducting microstrip antennas. Arrangements phase was analyzed in linear and planar configuration of its antennas are reported factors such arrays to settings and criteria of phase and the spacing between the elements that make the arrayst was reviewed in order to minimize losses due to secondary lobes. The antenna used has a rectangular patch Sn5InCa2Ba4Cu10Oy the superconducting material was analyzed by the method of Transverse Transmission Line (TTL) applied in the field of Fourier transform (FTD). The TTL is a full-wave method, which has committed to obtaining the electromagnetic fields in terms of cross-cutting components of the structure. The inclusion of superconducting patch is made using the boundary condition, complex resistive. Are obtained when the resonant frequency depending on the parameters of the antenna, radiation pattern of E-Plan and H-Plan for the M-phase arrangements of antennas in the linear and planar configurations for different values of phase and spacing between the elements.
Este trabalho tem como objetivo principal o estudo da aplica??o de antenas de microfita com patch supercondutor e uso dos arranjos de fase linear e planar. Foi apresentado um estudo das principais teorias que explicam com clareza a supercondutividade. As teorias BCS, Equa??es de London e modelo dos Dois Fluidos s?o as teorias que d?o suporte a aplica??o dos supercondutores nas antenas de microfita. Os arranjos de fase foram analisados em configura??es lineares e planares de suas antenas. Foram obtidos os fatores de arranjos para tais configura??es e os crit?rios da fase e do espa?amento entre os elementos que comp?e o arranjo, ao qual foram examinados com o objetivo de obter um l?bulo principal com alta diretividade e alto ganho. A antena utilizada tem como patch retangular o material supercondutor Sn5InCa2Ba4Cu10Oy foi analisada atrav?s do m?todo da Linha de Transmiss?o Transversa (LTT), aplicado no dom?nio da transformada de Fourier (FTD). O LTT ? um m?todo de onda completa, que tem como regra a obten??o dos campos eletromagn?ticos em termos das componentes transversais ? estrutura. A inclus?o do patch supercondutor ? feita utilizando-se a condi??o de contorno complexa resistiva. S?o obtidos resultados da freq??ncia de resson?ncia em fun??o dos par?metros da antena; diagramas de radia??o do Plano-E e Plano-H para os arranjos de fase de antenas nas configura??es lineares e planares para diferentes valores da fase e espa?amento entre os elementos.
37
Dundar, Burhan. "Investigations On Frequency Beam Scanning Microstrip (bsms) Antenna Structures." Master's thesis, METU, 2009. http://etd.lib.metu.edu.tr/upload/12610876/index.pdf.
Full textAbstract:
Beam scanning Microstrip (BSMS) antenna is designed to work at center frequency of 10 GHz for using in the scanning applications of 9 GHz to 11 GHz band. The design parameters are defined and by using an Electromagnetic Simulation software program, the parameters are optimized. A Beam Scanning Microstrip Antenna is produced as a prototype and the measurement&rsquos results are compared with theoretical results. In conclusion, the values of deviation between theoretical and experimental results are discussed.
38
Wu, Doris I., and James Rieger. "COMPUTER-AIDED DESIGN OF CIRCULARLY-POLARIZED CONFORMAL MICROSTRIP PATCH ANTENNA FOR TELEMETRY APPLICATIONS." International Foundation for Telemetering, 1994. http://hdl.handle.net/10150/608569.
Full textAbstract:
International Telemetering Conference Proceedings / October 17-20, 1994 / Town & Country Hotel and Conference Center, San Diego, CaliforniaPlanar microstrip antennas are desirable in many telemetry applications because they are small in size, light in weight, and conformal to most surfaces. The design and optimization of circularly-polarized omnidirectional microstrip arrays using a new software simulation tool are discussed in this paper. Critical design issues such as the optimization of each array element for circular polarization and the minimization of mutual couplings as well as feed network mismatch are examined. The software tool, which consists of a novel graphical user interface and a full-wave numerical simulator for a flat mounting surface, provides a testbed environment for the user to explore new designs as well as optimizing existing designs. Using this tool, the design of several wraparound arrays with different mounting cylinder radii are presented. Comparisons between measured and simulated data for two S-band 8-element wraparound arrays are also presented.
39
Khoshniat, Ali. "A Linearly and Circularly Polarized Active Integrated Antenna." DigitalCommons@USU, 2011. https://digitalcommons.usu.edu/etd/881.
Full textAbstract:
This thesis work presents a new harmonic suppression technique for microstrip patch antennas. Harmonic suppression in active integrated antennas is known as an effective method to improve the efficiency of amplifiers in transmitter side. In the proposed design, the antenna works as the radiating element and, at the same time, as the tuning load for the amplifier circuit that is directly matched to the antenna. The proposed active antenna architecture is easy to fabricate and is symmetric, so it can be conveniently mass-produced and designed to have circular polarization, which is preferred in many applications such as satellite communications.
The antenna simulations were performed using Ansoft High Frequency System Simulator (HFSS) and all amplifier design steps were simulated by Advanced Design System (ADS). The final prototypes of the linearly polarized active integrated antenna and the circularly polarized active integrated antenna were fabricated using a circuit board milling machine. The antenna radiation pattern was measured inside Utah State University's anechoic chamber and the results were satisfactory. Power measurements for the amplifiers' performance were carried out inside the chamber and calculated by using the Friis transmission equation. It is seen that a significant improvement in the efficiency is achieved compared to the reference antenna without harmonic suppression.
Based on the success in the single element active antenna design, the thesis also presents a feasibility of applying the active integrated antenna in array configuration, in particular, in scanning array design to yield a low-profile, low-cost alternative to the parabolic antenna transmitter of satellite communication systems.
40
Irci, Erdinc. "Low-Profile Wideband Antennas Based on Tightly Coupled Dipole and Patch Elements." The Ohio State University, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=osu1316456337.
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41
Iseri, Kadir. "Analysis Of Dual-polarized Aperture-coupled Microstrip Antennas With H-shaped Slots And Equivalent Circuit Modeling Of H-shaped Slots." Master's thesis, METU, 2012. http://etd.lib.metu.edu.tr/upload/12614527/index.pdf.
Full textAbstract:
This thesis includes the design, production and measurement of a wideband dualpolarized
X-band aperture-coupled microstrip patch antenna. The wideband and
dual-polarized operation is achieved through the use of H-shaped coupling slots.
Therefore, the equivalent circuit modeling of a microstrip line fed H-shaped slot is
also studied in this thesis. A step-by-step procedure is followed during the design
process of the dual-polarized aperture-coupled microstrip antenna. First, an
aperture-coupled microstrip antenna with a single rectangular slot, that exhibits a
wideband characteristic for single polarization, is designed. Then, the design
procedure is repeated for an antenna with H-shaped slot in order to satisfy the same
specifications with a shorter slot. Finally, dual-polarized aperture-coupled
microstrip antenna is designed. At this configuration, two H-shaped slots are used
and they are placed orthogonal to each other. During the design process, the effects
of antenna parameters on the input impedance characteristics of the antenna are
investigated. These parametric analyses are done in CST Microwave Studio®. The v designed dual-polarized wideband aperture-coupled microstrip antenna is manufactured. Simulation results and measurement results are compared. During the equivalent circuit modeling of an H-shaped slot fed by a microstrip line, an approach based on the reciprocity theorem is utilized. The method was originally proposed for rectangular shaped slots, in this thesis it is generalized for arbitrarily shaped slots. Software codes are developed in MATLAB to calculate the equivalent impedance of the slot.
42
Zivanovic, Bojana. "Series-Fed Aperture-Coupled Microstrip Antennas and Arrays." Scholar Commons, 2012. http://scholarcommons.usf.edu/etd/4425.
Full textAbstract:
The focus of this dissertation is on the development and circuit modeling of planar series-fed, linear- and circular-polarized microstrip aperture-coupled antennas and N-element arrays operating in C-band. These arrays were designed to be used as part of airborne or land-based frequency-hopped communication systems. One of the main objectives of this work was to maintain a constant beam angle over the frequency band of operation. In order to achieve constant beam pointing versus frequency, an anti-symmetric series-fed approach using lumped-element circuit models was developed. This series feed architecture also balances the power radiated by each element in the N-element arrays.
The proposed series-fed approach was used in the development of four-element series-fed aperture-coupled arrays with 15% 10 dB impedance bandwidth centered at 5 GHz and a gain of 11.5 dB, to construct an omni-directional radiator. Omni-directional radiators with pattern frequency stability are desired in a multitude of applications; from defense in tactical communications, information gathering, and detection of signal of interest to being part of sensors in medical applications. A hexagonal assembly of six series-fed microstrip aperture-coupled four-element arrays was used to achieve the omni-directional radiation with 0.6 dB peak to peak difference across 360˚ broadside pattern and 0.6 dB gain variation at the specific azimuth angle across 15% impedance bandwidth. Given that each of these six arrays can be individually controlled, this configuration allows for individual pattern control and reconfiguration of the omni-directional pattern with increased gain at specific azimuth angles and the ability to form a directional pattern by employing a fewer number of arrays. Incorporating a beam-forming network or power distribution network is also possible.
Wide 3 dB circular polarization (CP) bandwidth was achieved without external couplers and via only a single feed with a unique Z-slot aperture-coupled microstrip antenna. A single RHCP Z-slot aperture-coupled antenna has ∼10% CP and 10 dB impedance bandwidth. The series-fed network consisting of lumped elements, open-circuited stubs and transmission lines was subsequently developed to maintain more than 5% CP and 10% 10 dB impedance bandwidth in the series-fed four-element Z-slot aperture-coupled CP array that could also be used for-omni-directional radiation.
43
Tastan, Mehmet. "Analysis And Design Of A Circularly Polarized Microstrip Antenna." Master's thesis, METU, 2005. http://etd.lib.metu.edu.tr/upload/12607868/index.pdf.
Full textAbstract:
In this study we tried to design a microstrip antenna, to get a suitable radiation pattern for a LEO satellite. Our aim is to get a radiation pattern that has a maximum power which is not in the broadside direction to the antenna surfaceinstead broadside radiation has a relatively lower power density. Maximum power radiation is desired to be at about 30 &ndash
50 degrees angle beyond the normal to the antenna surface. We desire circularly polarized radiation. We used two concentric antennas
one is a circular patch at the center and the other is an annular ring which is used at the outer region. By using Ansoft Ensemble 8.0 software, we design an antenna which has a resonance frequency at 8.2 GHz. Using the result of the program we design the real antenna. The measurement results are compared with the simulation results.
44
Kornbau, Nathan Thomas. "Design and analysis of a wideband patch antenna for use with a miniature radar system." Diss., Connect to online resource - MSU authorized users, 2008.
Find full text
45
Ooi, Shirt Fun. "Design of a high efficiency class-F power amplifier integrated with a microstrip patch antenna." Thesis, Northumbria University, 2007. http://nrl.northumbria.ac.uk/2245/.
Full textAbstract:
This thesis presents the research carried out into the effects of load and source harmonic terminations on the efficiency of a class-F power amplifier (PA). A demonstration on the direct integration of the class-F PA and an H-shaped patch antenna using an active integrated antenna (AIA) approach is also presented. To obtain a high efficiency PA, it is necessary to ensure that the power dissipated in the active device is minimised and this is achieved by ensuring that the overlapping area between the drain voltage and current waveforms in the time domain is minimised. To minimise this overlapping area, optimum source and load harmonic impedances for the fundamental frequency, and second and third harmonics, are obtained using a novel application of the simulated load/source-pull method. New forms of harmonic matching networks were designed to ensure that the active device is terminated by the optimum impedances at the gate and drain for maximum efficiency. Three PAs were designed, one operating at 0.9 GHz and the other two at 2.45 GHz. For the 0.9 GHz PA the load matching network was designed to obtain the required optimum impedances at the fundamental frequency, and second and third harmonics. As the effect of gate capacitance is small at this frequency, the source matching network was designed to obtain a conjugate match at the fundamental frequency only. At the higher frequency of 2.45 GHz, the gate capacitance has a larger effect on the efficiency of the PA and hence two designs were investigated and compared. In the first PA design the load and source matching networks were designed to obtain optimum impedances at the fundamental frequency and second harmonic. For the second PA design, these networks were designed to obtain optimum impedances at the fundamental frequency, and second and third harmonics. For these three PAs the simulated drain voltage/current waveforms, return loss, stability factor, power gain, output power and power added efficiency (PAE) are presented. The practical results are compared with those obtained by simulation. Each PA produced a PAE of greater than 70% and good agreement was obtained between the simulated and measured results. The PAE obtained in these works is comparable to that reported in published papers. Based on this research five papers have been published in journals and conferences. An H-shaped microstrip patch antenna is used in the active integrated antenna (AIA) design. The antenna must not only act as a radiator and a harmonic suppresser but also as an optimum load for the PA so that it can be connected directly to the active device in order to obtain maximum efficiency. An extensive study on this antenna was carried out. The formulas for the first four mode frequencies were derived using odd and even mode analysis while a new and simpler formula for the fourth mode frequency was obtained. A systematic design approach to obtain the dimensions of the antenna is presented for an antenna operating at a given fundamental mode frequency. For matching, a new explicit matrix input impedance formula for the H-shaped antenna has been obtained using segmentation method. Using this formula, the location of the probe feed could be adjusted to obtain the required impedance at the pre-assigned frequency. MathCAD programming is used to implement the calculations in the design of two antennas. Good agreement between the predicted, simulated and measured results is obtained for the resonant mode frequencies, input impedance and return loss. Based on this research two papers have been published in journals.
46
N?brega, Clarissa de Lucena. "Otimiza??o dos par?metros de monopolos planares de microfita para aplica??es em sistemas de banda ultra larga." Universidade Federal do Rio Grande do Norte, 2008. http://repositorio.ufrn.br:8080/jspui/handle/123456789/15200.
Full textAbstract:
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Previous issue date: 2008-10-21Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior
This work presents a theoretical and experimental investigation about the properties of microstrip antennas for ultra-wideband systems. Configurations of elliptic monopoles with different eccentricities and circular monopoles are considered. Two prototypes for each antenna configuration were built, one with the typical microstrip configuration and the other is similar to the first, except for a small aperture in the ground plane. Therefore, this work proposes to modify the configuration of the ground plane of the monopoles designed adding a rectangular stub, in order to optimize and improve the performance of such structures. The obtained results show that the introduction of that rectangular aperture in the ground plane allows an improvement of the frequency response for the considered antenna propotypes. It is observed a good agreement between the measured and simulated results. Finally, some proposals for future works are presented
Este trabalho apresenta uma investiga??o te?rica e experimental sobre as propriedades de antenas de microfita para sistemas de banda ultra larga. S?o consideradas configura??es de monopolos el?pticos com excentricidades diferentes, e monopolos circulares. Foram constru?dos dois prot?tipos para cada configura??o de antena, um com a configura??o t?pica de microfita e outro similar ao primeiro, mas com uma pequena abertura no plano de terra. Assim, este trabalho objetiva modificar a configura??o do plano de terra dos monopolos projetados atrav?s da inser??o de um recorte retangular, para fins de otimiza??o e melhoria nos desempenhos das estruturas. Os resultados obtidos mostram que a introdu??o dessa abertura retangular no plano de terra permite melhorar a resposta em freq??ncia das antenas consideradas. Observa-se uma boa concord?ncia entre os resultados medidos e simulados. Algumas propostas para a realiza??o de trabalhos futuros s?o apresentadas
47
Chen, Shing-Hau, and 陳星豪. "Reconfigurable Microstrip Ring Patch Antenna." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/37865871203503266324.
Full textAbstract:
碩士國立彰化師範大學
電機工程學系
95
The designs of a reconfigurable ring patch antenna are proposed and studied in this dissertation. The thesis is mainly divided into three topics. First, the design of a ring patch antenna with wideband and dual-frequency operations is presented. The antenna consists of a parasitic square ring patch that is shorted to the ground plane through two shorting walls and is excited by a top-loaded coaxial probe. For the proposed design, while the side length of the square ring patch is about 0.3 free-space wavelengths and the antenna height is less than 0.1 free-space wavelengths, a 10 dB-input-impedance bandwidth of more than 50 % can be achieved. Also, the antenna can provide stable monopole-like conical radiation patterns across the impedance bandwidth. In addition, it is also found that two different resonant modes, patch-loaded monopole mode and normal patch mode, can be simultaneously excited in the shorted patch antenna structure by a coupling rectangular strip inside the ring patch. The antenna can radiate monopole-like and broadside patterns at the two operating frequencies, respectively. Second, a reconfigurable patch antenna with the functions of switchable radiation patterns, and polarizations is presented. The antenna is composed of a ring patch and four shorting walls. By controlling the connections states between the ring patch and shorting walls through pin diodes, the antenna can be operated at different modes to achieve the switching of the radiation patterns and polarizations. Moreover, three pairs of the shorting walls with various widths are integrated into the antenna to excite the patch-load monopole mode, and the resonant frequency can be changed by activating various pair of the shorting walls. From the obtained results, the three operating frequencies can occupy a successive impedance bandwidth, which makes the antenna with wide band operation.
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Srivastava, Prateek. "MULTIBAND TRIANGULAR PATCH ANTENNA." Thesis, 2015. http://dspace.dtu.ac.in:8080/jspui/handle/repository/14330.
Full textAbstract:
In telecommunication, there are several types of microstrip antennas (also known as printed
antennas) the most common of which is the microstrip patch antenna or patch antenna. A patch
antenna is a narrowband, wide-beam antenna.
Microstrip antennas are relatively inexpensive to manufacture and design because of the simple 2-
dimensional physical geometry. They are usually employed at UHF and higher frequencies because
the size of the antenna is directly tied to the wavelength at the resonant frequency. A single patch
antenna provides a maximum directive gain of around 6-9 dB. It is relatively easy to print an array
of patches on a single (large) substrate using lithographic techniques. Patch arrays can provide
much higher gains than a single patch at little additional cost; matching and phase adjustment can
be performed with printed microstrip feed structures, again in the same operations that form the
radiating patches. The ability to create high gain arrays in a low-profile antenna is one reason that
patch arrays are common on airplanes and in other military applications
The most commonly employed microstrip antenna is a rectangular patch. The rectangular patch
antenna is approximately a one-half wavelength long section of rectangular microstrip transmission
line. When air is the antenna substrate, the length of the rectangular microstrip antenna is
approximately one-half of a free-space wavelength. As the antenna is loaded with a dielectric as its
substrate, the length of the antenna decreases as the relative dielectric constant of the substrate
increases. Here a rectangular patch antenna resonating at 2.4 GHz is designed and their reflection
coefficient, radiation pattern & polar plot is drawn & analysed. Now the Triangular patch antenna
working on same resonant frequency is designed which is having less size compared to the
rectangular patch antenna.
The triangular microstrip antenna is one of the shapes of microstrip antennas which have radiation
properties similar to that of the rectangular antenna but with the advantage of being physically
smaller. The simplest of triangular shapes is equilateral antenna which has more directivity with
compact size.
In this project rectangular patch has been designed to operate at resonance frequency of 2.4 GHz for
Wi-Fi application. Then a triangular patch antenna of same resonating frequency is designed. It has
been seen from the result that the size required for the triangular antenna to resonate at the same
frequency is less as compared to rectangular patch antenna.
Then triangular slots have been made in the same triangular patch antenna so that it is converted
into the fractal antenna and the design is simulated. The result obtained for two fractal geometry
shows that the return loss of the antenna at 2.4 GHz is less as compared to the same dimensions of
triangular patch antenna. Fractal antenna is having many advantages over the simple patch antenna
like miniaturization, better input impedance matching & wideband / multiband behaviour.
A new triangular multiband patch antenna has been designed to operate at resonant frequencies 1.1
GHz, 2 GHz & 3 GHz.. again the triangular slots are cut in this design to make it fractal antenna so
we get the lower return loss at resonant frequencies.Dr. Priyanka Jain (Assistant Professor) Department of Electronics & Communication Engineering
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Raju, Robin. "Investigation of miniaturized microstrip antenna efficiency enhancement." 2015. http://hdl.handle.net/1993/30652.
Full textAbstract:
Radiation Efficiency improvement of miniaturized microstrip antenna is studied in this thesis. It is shown that, the loss reduction in miniaturized Microstrip Antenna can be achieved through two possible ways. The first is by modifying the materials used for building the antenna, and the second method is by increasing the radiation conductance of the antenna. Material modification at nano/micro scale by replacing conductors with Metallo-Dielectric one dimensional medium for applications in loss reduction is investigated first. It is shown by the Transfer Matrix Method and using simulations that, for a one dimensional medium replacing very thin conductors (less than skin depth) by laminated multilayered conductors reduce losses. However, the improvement does not exceed the case of single conductor which is a few times thicker than skin depth. Secondly, the efficiency improvement of a small H-Shaped patch antenna by using closely coupled stacked parasitic resonators is studied. It is shown that significant improvement in efficiency can be achieved with minimal changes in the foot print, radiation pattern and cross polarization levels of the antenna. The effect of the overall thickness and superstrate dielectric constant on the efficiency improvement is studied parametrically. It is shown that by using 5 radiating resonators and appropriate choice of inter-conductor dielectric constant, for a small increase in thickness of 0.127mm (5mil), the radiation efficiency can be increased from 2.34% to 6.3%. This efficiency improvement can be made very significant from 2.4% to 33%, by increasing the height to 1.27mm (50mil). These translate to a gain improvement of 4dB and 13dB, respectively. This technique is also demonstrated experimentally in H-Shaped antennas with two different levels of miniaturizations.October 2015
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SHARMA, KHUSHBU. "A RECONFIGURABLE PATCH ANTENNA WITH EBG STRUCTURE." Thesis, 2018. http://dspace.dtu.ac.in:8080/jspui/handle/repository/16535.
Full textAbstract:
Microstrip antennas are widely used in wireless communications because of their compatibility, low profile, low power consumption and low cost. The capability to select the frequency is essential for diverse missions and this is achieved by a Reconfigurable Antenna. Resonant frequency of an antenna is changed by reconfiguring its geometrical structure. To achieve reconfigurability RF switching devices such as PIN diodes , photoconductive switches, micro-electromechanical system (MEMS) switches and FETs can be used.
Electromagnetic Bandgap (EBG) Structures that are those structures in which each element follows periodicity. Hence using EBG structures in a conventional patch antenna increase bandwidth and provide better suppression of harmonics .
This major project combines these two structures designing a reconfigurable patch antenna with EBG structure in which PIN diodes are used as switch as they provide fast switching speeds, reasonably high current handling capabilities, reliability and ease of modelling.
First of all the phase reflection diagram for a unit cell of proposed EBG is shown, after that bandgap of full EBG structure is shown using suspended transmission line method. Different EBG structures’ bandgaps are also compared. Then the EBG structure is combined with a reconfigurable patch antenna and simulation results are presented in terms of return loss, VSWR and radiation pattern. A comparison between simulated results for reconfigurable antenna with and without EBG structures for return loss and radiation pattern is also provided. All the above simulations are carried out by CST STUDIO SUITE 2014.