Dissertations / Theses: 'MICROSTRIP PATCH ANTENNAE'

1

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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2

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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3

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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4

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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5

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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6

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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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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8

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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9

Ballikaya, Elif. "Analysis Of Slot Coupled Microstrip Patch Antennas." Master's thesis, METU, 2008. http://etd.lib.metu.edu.tr/upload/12609094/index.pdf.

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Method of Moments (MoM)/Green&rsquo
s function formulation is developed for the analysis of electromagnetic radiation from planar rectangular microstrip antennas with different feeding techniques. Investigated structures are microstrip line fed patch antenna, proximity coupled patch antenna and slot coupled patch antenna. For all these structures equivalent problems are defined. Then, integral equations where currents are the unknowns are obtained from boundary conditions and by using spectral domain representation of Green&rsquo
s functions. Finally, MoM is applied to convert these integral equations to a system of linear equations. Currents on the conducting surfaces as well as equivalent magnetic currents on the apertures are modeled as a sum of piecewise sinusoidal subdomain basis functions with unknown coefficients which are calculated by solving the system of linear equations. Based on the formulations provided in this study, a Fortran code is developed. Numerical results calculated by using the code are presented in the form of patch and line currents and input impedances. Presented results are in good agreement with the results given in the literature.

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10

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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11

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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12

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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13

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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14

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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15

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&ndash
1880 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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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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17

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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18

Gok̈ben, Il̇han. "Prototype fabrication and measurements of uplink and downlink microstrip patch antennas for NPSAT-1 /." Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2003. http://library.nps.navy.mil/uhtbin/hyperion-image/03Mar%5FGokben.pdf.

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Thesis (M.S. in Electrical Engineering)--Naval Postgraduate School, March 2003.
Thesis advisor(s): Jovan Lebaric, Richard W. Adler. Includes bibliographical references (p. 49). Also available online.

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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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20

Economou, Lazaros. "Circular microstrip patch antennas for mobile communication systems." Thesis, University of Kent, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.242815.

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21

Batchelor, John. "Annular ring microstrip patch antennas for mobile communications." Thesis, University of Kent, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.282579.

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22

Rostbakken, Olaf. "Automatic frequency tuning control of microstrip patch antennas." Thesis, University of Bristol, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.389137.

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23

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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24

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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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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Zou, Xinlei. "Bandwidth enhancement techniques for probe-fed microstrip patch antennas." Thesis, University of Ottawa (Canada), 2005. http://hdl.handle.net/10393/27106.

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Many bandwidth enhancement techniques for microstrip patch antennas have been developed since the 1970's. Except for an IEEE collection of reprints which appeared in 1995, relatively little work has been done to review and categorize these techniques. As a result, the published research and design of broadband microstrip antennas has become somewhat unsystematic. In this thesis, papers on broadband microstrip antennas have been reviewed. Using full-wave electromagnetic simulation, the important performance parameters such as the bandwidth, realized gain, antenna efficiency, radiation efficiency and radiation patterns of broadband microstrip patch antennas have been considered. Based on these results, bandwidth enhancement techniques have been categorized in two broad classes, namely those applicable when electrically-thick low-permittivity substrates are used, and those applicable to electrically-thin high-permittivity substrates. These broad classes have been sub-divided into several sub-classes in a structured manner that aids the understanding of the bandwidth enhancement methods. A summary of these techniques, linked to a comparison of resulting microstrip patch antenna performance obtained from full-wave analysis of the sub-classes, is provided. It is also shown, through a specific example, how the increased understanding afforded by this categorization can lead to the development of new broad bandwidth geometries that can offer some advantages over existing ones.

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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.

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Bhalla, Ritu. "Analysis of broadband and dual band microstrip patch antennas." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2001. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/MQ62692.pdf.

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30

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, California
This 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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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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Made available in DSpace on 2014-12-17T14:55:45Z (GMT). No. of bitstreams: 1 HugoMCAM_DISSERT_partes autorizadas.pdf: 586809 bytes, checksum: e96d1467d4ab6c5fa6da39927cde0bca (MD5) Previous issue date: 2010-07-09
Coordena??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.

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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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34

Gokben, Ilhan. "Prototype fabrication and measurements of uplink and downlink microstrip patch antennas for NPSAT-1." Thesis, Monterey, California. Naval Postgraduate School, 2003. http://hdl.handle.net/10945/1109.

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Approved for public release; distribution is unlimited
This thesis addresses the prototyping, measurement, and validation of two circularly polarized microstrip patch antennas designed by LTJG Mahmut Erel for the NPSAT-1. The antenna system (receive and transmit), consisting of two antennas on a ground plane and their feed systems, was field-tested. The results were compared to the CSTÊ¼ Microwave Studio. Finite Difference Time Domain (FDTD) software package predictions in order to verify that this design satisfies the NPSAT-1 requirements for bandwidth, free-space radiation pattern and low-profile shape.
Lieutenant Junior Grade, Turkish Navy

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35

Onat, Sinan. "Re-configurable Microstrip Patch Antennas Controlled By Rf Mems Switches." Master's thesis, METU, 2006. http://etd.lib.metu.edu.tr/upload/12607969/index.pdf.

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This thesis presents design, fabrication and testing of a number of multi-frequency band microstrip-fed re-configurable microstrip patch antennas. All re-configurable antennas are designed to change from one resonance frequency to another by an electronic control of RF MEMS switches, one at a time. Besides a fixed size slot on the patch, switches are placed in insets for satisfying better input match at each resonance frequency individually. Also some switches are placed into the slot for adding another resonance frequency to change the effective slot-length like effective inset length changing.To actuate the RF MEMS switches in the configured way, DC-stubs are also designed to apply required potential difference between switch ports and the carrier. These stubs exhibit RF-open at switch side to prevent any RF leakage, and DCground on the other side. That RF short-to-open conversion is accomplished together with feed structure
with a taper depending on the feed network selected. All devices introduced here are built by Microwave Research Group in Electrical and Electronics Department, Middle East Technical University. Depending on the sensitivity of structure, some devices are built by RF MEMS group in Microelectronic Production Plant for MEMS (METU &
#8211
MET) during the thesis study. Therefore this study is the continuation of the first national work on fabrication of RF MEMS devices.

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36

Jahagirdar, Dhananjay R. "Non-leaky conductor-backed coplanar waveguide-fed microstrip patch antennas." Thesis, University of Southampton, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.241874.

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SaÌnchez-HernaÌndez, David A. "Active microstrip patch antennas for monolithic microwave integrated circuits (MMICs)." Thesis, King's College London (University of London), 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.362513.

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Elsdon, Michael. "An investigation of reduced size planar fed microstrip patch antennas." Thesis, Northumbria University, 2005. http://nrl.northumbria.ac.uk/1183/.

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The primary goal of this research work is to investigate the use of slot loading in reduced size planar fed microstrip patch antennas and develop new antenna structures based on this technique. At present, little theoretical investigation or design methodology exists to support the design of compact structures and research in this field is largely empirical. Moreover, little work exists on the use of planar fed designs. This necessitates a primary requirement to firstly address this knowledge gap. To facilitate this, a mathematical modelling technique that can be applied to such structures is developed. This is based upon the segmentation and Green's function approach. Using this model, the performance of slot loaded structures in terms of circuit characteristics including resonant frequency, input impedance, and Q factor is determined. Using this knowledge, a design procedure is established and subsequently used to provide a framework for the design of novel slot loaded antennas for specific applications. Several new slot loaded patch antenna configurations are designed that produce size reduction whilst allowing the use of a planar feed. The validity of the designs are confirmed through the use of commercial full-wave modelling software package Ensemble. Three linear polarised antennas are presented which are shown to achieve size reduction of 12, 40 and 55% respectively. Several compact circular polarised antenna structures are successfully implemented producing size reduction of up to 43%. A novel design for a reduced size antenna with a dual frequency response is also presented with a tuneable frequency ratio of between 1.03 — 2.0. Prototypes of the aforementioned antennas are fabricated and tested, and practical results are shown.

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39

Akgun, Erdem. "Millimeter Wave Microstrip Launchers And Antenna Arrays." Master's thesis, METU, 2006. http://etd.lib.metu.edu.tr/upload/12607863/index.pdf.

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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.

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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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Acimovic, Igor. "Improving port isolation in dual-polarized microstrip patch antenna arrays." Thesis, University of Ottawa (Canada), 2006. http://hdl.handle.net/10393/27323.

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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.

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42

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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43

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.

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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&rsquo
s 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.

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44

Zivanovic, Bojana. "Series-Fed Aperture-Coupled Microstrip Antennas and Arrays." Scholar Commons, 2012. http://scholarcommons.usf.edu/etd/4425.

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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.

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45

Almutawa, Ahmad Tariq. "Log-Periodic Microstrip Patch Antenna Miniaturization Using Artificial Magnetic Conductor Surfaces." Scholar Commons, 2011. http://scholarcommons.usf.edu/etd/2982.

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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.

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46

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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47

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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48

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.

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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.

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49

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.

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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.

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50

Kawser, Mohammad Tawhid. "Investigation of a Novel Dual Band Microstrip/Waveguide Hybrid Antenna Element." Thesis, Virginia Tech, 2005. http://hdl.handle.net/10919/33660.

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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

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