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1
Smith, Peter. "Moment method analysis of microstrip/stripline fed slot radiators including polarisation agility." Thesis, Heriot-Watt University, 1995. http://hdl.handle.net/10399/744.
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2
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.
3
Mustafa, Incebacak. "Design Of Series-fed Printed Slot Antenna Arrays Excited By Microstrip Lines." Master's thesis, METU, 2010. http://etd.lib.metu.edu.tr/upload/12612447/index.pdf.
Full textAbstract:
Series-fed printed slot antenna arrays excited by microstrip lines are low profile, easy to manufacture, low cost structures that found use in applications that doesn&rsquot require high power levels with having advantage of easy integration with microwave front-end circuitry. In this thesis, design and analysis of microstrip line fed slot antenna arrays are investigated. First an equivalent circuit model that ignores mutual coupling effects between slots is studied. A 6-element array is designed by using this equivalent circuit model. From the measurement and electromagnetic simulation results of this array, it is concluded that mutual coupling effects should be considered in order to achieve a successful design that meets the design specifications related to the main beam direction and sidelobe levels of the antenna. Next, an improved equivalent circuit model proposed for stripline fed slot antenna arrays is studied. It is observed that, the mutual coupling effects are incorporated into the equivalent model through the utilization of active impedance concept. Finally, the design equations proposed in the improved equivalent circuit model are derived for the microstrip line fed slot antenna array structure. To demonstrate the validity and the accuracy of the derived design equations, results obtained by the proposed analysis method are compared with simulation and measurement results. It is concluded that the proposed method successfully predicts the radiation pattern of the array by including the mutual coupling effects.
4
Cirineo, Tony, Rick Davis, Marvin Byrd, and Scott Kujiraoka. "Design and Development of a Thin Conformal C-Band Telemetry Antenna for a Small Diameter Missile." International Foundation for Telemetering, 2011. http://hdl.handle.net/10150/595618.
Full textAbstract:
ITC/USA 2011 Conference Proceedings / The Forty-Seventh Annual International Telemetering Conference and Technical Exhibition / October 24-27, 2011 / Bally's Las Vegas, Las Vegas, NevadaThis paper will present the preliminary design of a C-Band telemetry antenna mounted conformal to a small diameter missile. Various design studies and options will be explored leading to a preliminary design that best meets system requirements. Simulation results are presented for various options and the rationale for down selection to final configuration is discussed.
5
Yildirim, Meltem. "Design Of Dual Polarized Wideband Microstrip Antennas." Master's thesis, METU, 2010. http://etd.lib.metu.edu.tr/upload/12612023/index.pdf.
Full textAbstract:
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.
6
Farooqui, Muhammad Fahad. "Compact circularly polarized slot-ring antenna and microstrip bandpass filter using triangular open-loop resonators." Texas A&M University, 2006. http://hdl.handle.net/1969.1/4969.
Full textAbstract:
In this thesis two different research topics are undertaken, both in the area of compact
RF/microwave circuits design. The first topic involves the design of a compact circularly
polarized (CP) slot-ring antenna. A study of several compact CP microstrip and slotline
antennas reported in the past has been carried out. In this research, a method of reducing
the size of a printed slot-ring antenna is proposed. The reduction in size is achieved by
introducing meandered-slot sections in the ring. Circular polarization is achieved by
introducing an asymmetry, also a meandered-slot section, and feeding the antenna at an
angle of 45o from the asymmetry using a microstrip feed line. The minimum axial ratio
of 0.4 dB is obtained at 2.46 GHz, which is the operating frequency of the antenna. The
size of the proposed antenna is reduced by about 50% compared to a conventional CP
slot-ring antenna and it displays a CP bandwidth of about 2.5%. The simulated and
measured results are presented, and they are in good agreement. The small size of the
antenna makes it very suitable for use in modern RF/microwave wireless systems which
require compact, low cost, and high performance circuits. Moreover, its CP behavior
makes it more attractive for applications such as satellite communications. The second topic in the thesis involves the design of a compact microstrip bandpass
filter using triangular open-loop resonators. A new compact three-pole microstrip
bandpass filter using four triangular open-loop resonators is presented. A fourth
resonator is placed to provide cross-coupling in the structure which gives a better skirt
rejection. The measured pass-band center frequency is 2.85 GHz. The filter demonstrates
about 7% bandwidth with insertion loss of less than 1 dB in the passband, a return loss
of greater than 15 dB and out-of-band rejection of greater than 30 dB. The simulated
and measured results are in good agreement. The proposed filter is very attractive for use
in modern wireless systems which require bandpass filters having compact size, low
insertion loss, high selectivity, and good out-of-band rejection.
7
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.
8
Agbor, Ikechukwu Wilson. "Adaptive Slot Location in the Design of Slotted Microstrip Multi-Frequency Antenna for Radionavigation and Radiolocation Applications." Thesis, University of North Texas, 2020. https://digital.library.unt.edu/ark:/67531/metadc1707319/.
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In light of incidents and concerns regarding the vulnerability of the global positioning system (GPS), the main purpose of the thesis is to look at alternative systems for radio guidance and to put up a serious study on such alternatives with receive and transmit antenna. There is also the need to design such antennas with multiple frequencies to offer robustness in the unlikely event that such adversarial attacks on the GPS happen. The basis on which such alternative antennas are designed is a slotted microstrip. The characteristics of the slot or slots on the microstrip are analyzed by mapping their exact locations on the patch and then noting the resultant center frequencies, the return losses, and the bandwidth. The activities associated with this also focus on the design, fabrication, validation, and characterization of one or more slotted antennas prototypes. The measurement of the antenna prototypes does confirm several frequencies that coexist to see applications, in aeronautical radionavigation, fixed-mobile radionavigation, and radiolocation. The antennas could also feature in a wide-area augmentation system (WAAS), satellite ground link system (SGLS) as well as in surveillance and precision approach radars. Some variations of the antenna are deployed in the areas of law enforcement, surveillance, and unmanned aerial vehicle (UAV). Applications of the antenna in an unmanned ground vehicle (UGV) are feasible due to its multiple resonant frequencies. Radiolocation and radionavigation antennas have also been known to be mounted in UAVs or on tethered balloons along the borders of the United States to detect low-flying aircraft in support of drug interdiction programs.
9
Lindberg, Peter. "Wideband Active and Passive Antenna Solutions for Handheld Terminals." Doctoral thesis, Uppsala : Acta Universitatis Upsaliensis, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-7445.
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10
Hermány, Roman. "Vícevrstvá textilní anténní řada." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2018. http://www.nusl.cz/ntk/nusl-377157.
Full textAbstract:
Thesis focuses on the design and development of three possible methods to power the serial patch array and optimization of the chosen design. The antenna array is conceived as a multi-layered structure formed on a 3D textile substrate. The objective of this work is to identify the best possible configuration of antenna array for the use in automotive and aerospace industry. The first concept – array coupled by near microstrip line – proved in the case of the more serial elements as non-functional. The second concept – aperture coupled array – is unsuitable for use in close proximity to the electrically conductive shell of the aircraft. The third concept – array coupled with textile integrated waveguide – seems like the best possible solution. The design of the array coupled with textile integrated waveguide was optimized in consideration of the production process. The impedance bandwidth of this proposed three elements antenna is 890 MHz, the gain in the main lobe direction is 11.8 dBi.
11
La, Rosa Henrry. "Investigation of a Rectenna element for infrared and millimeter wave application." [Tampa, Fla.] : University of South Florida, 2007. http://purl.fcla.edu/usf/dc/et/SFE0002221.
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12
Ballikaya, Elif. "Analysis Of Slot Coupled Microstrip Patch Antennas." Master's thesis, METU, 2008. http://etd.lib.metu.edu.tr/upload/12609094/index.pdf.
Full textAbstract:
Method of Moments (MoM)/Green&rsquos 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.
13
Mikulášek, Tomáš. "Mikropáskové flíčkové antény napájené vlnovodem integrovaným do substrátu." Doctoral thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2013. http://www.nusl.cz/ntk/nusl-233587.
Full textAbstract:
Dizertační práce je zaměřena na výzkum mikropáskových flíčkových antén a anténních řad napájených vlnovodem integrovaným do substrátu (SIW). Využitím vlnovodu integrovaného do substrátu pro napájení mikropáskové flíčkové antény dochází ke kombinaci výhodných vlastností obou struktur. Výsledkem je kompaktní anténní struktura, jejíž napájecí vedení neprodukuje parazitní záření a neovlivňuje tak vyzařovací charakteristiku antény. Práci lze z věcného hlediska rozdělit do dvou částí. První část práce (kapitola 2) je zaměřena na návrh flíčkových antén a jejich navázání na vlnovod integrovaný do substrátu. První dvě navržené flíčkové antény využívají vlnovod integrovaný do substrátu a štěrbinu nebo koaxiální sondu pro buzení lineárně polarizované vlny. Napájení koaxiální sondou je dále použito pro buzení kruhově polarizované flíčkové antény. Za účelem získání širšího pásma osového poměru je navrženo napájení flíčkové antény ve dvou bodech. Funkčnost všech anténních struktur je popsána pomocí parametrických simulací a ověřena realizací a měřením vyrobených prototypů antén. Prezentované napájecí metody představují nový způsob napájení pro mikropáskové antény využívající technologii SIW. Ve druhé části práce (kapitola 3) je pojednáno o implementaci štěrbinou napájené mikropáskové anténní struktury do malých anténních polí o velikosti 2x2 a 1x4. V případě lineární řady je uvažováno amplitudové rozložení pro optimální potlačení postranních laloků. Obě navržené anténní řady jsou ověřeny měřením a v porovnání s podobnými anténními řadami dostupnými v literatuře dosahují širšího pracovního pásma kmitočtů a vyššího zisku.
14
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.
15
Akhavan, Haj Ghadir. "Analysis of single and coupled microstrip-fed slot antennas." Thesis, University of Essex, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.339226.
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16
Weigel, Filip. "Rekonfigurovatelná štěrbinová anténní řada." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2016. http://www.nusl.cz/ntk/nusl-242136.
Full textAbstract:
This master's thesis deals with the basic principles of slot antennas. Models of antennas were simulated in a selected electromagnetic simulator CST MICROWAVE STUDIO (CST MWS). There are several models of slot antennas which are optimized for communication in the car at a frequency 8 GHz.
17
Cihangir, Aykut. "Radiation Characteristic Analysis Of Tapered Slot Antennas." Master's thesis, METU, 2010. http://etd.lib.metu.edu.tr/upload/12612367/index.pdf.
Full textAbstract:
The aim of this study is to investigate the effects of changes in the physical parameters of tapered slot antennas (TSA) on their radiation characteristics and also to explore the possibility of reconfiguration in the radiation pattern of TSA by
switching between two different types of tapering.
There are mainly three physical parameters that affect the radiation pattern of TSAs. These are antenna length, aperture width and the ground extension. After designing a wideband microstrip line to slot line transition, the effect of antenna parameter variations on the beamwidth and sidelobe level of the antenna are investigated through the use of a commercially available electromagnetic simulation software
HFSS by ANSOFT. The radiation characteristics of constant width slot antennas (CWSA) and linearly tapered slot antennas (LTSA) are compared. It is observed that
CWSAs exhibit narrower beamwidth and higher sidelobe level whereas linearly tapered slot antennas (LTSA) have wider beamwidth with lower sidelobe level compared to each other. A novel switching architecture between CWSA and LTSA is
proposed to obtain a reconfigurable antenna.
18
Matin, Mohammad Abdul. "Design and analysis of slot loaded microstrip patch antennas for ultrawideband (UWB) systems." Thesis, University of Newcastle Upon Tyne, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.437987.
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19
Goksu, Mesut. "Analysis Of Slot Coupled Patch Antennas Using Closed Form Green." Master's thesis, METU, 2009. http://etd.lib.metu.edu.tr/upload/12610996/index.pdf.
Full textAbstract:
In this thesis, an analysis technique for the slot coupled patch antennas using MoM in
conjunction with the closed form Green&rsquos functions is presented. Slot coupled patch antennas are fed by a microstrip open stub which is coupled to the patch through an electrically small slot. Current distributions over the microstrip line, slot line and the patch are represented by rooftop basis functions. First, a relatively simple structure, microstrip coupled slot line is investigated using the proposed technique. Then the method is extended to the slot coupled patch antenna geometry. By using the method, current distributions on the feedline and the patch are calculated for a generic slot coupled patch antenna. Then by using the distributions, return scattering parameters of the antenna is approximated with complex exponentials using Prony&rsquo
s method. A parametric study is carried out to observe the effect of each antenna component on the antenna performance. Current distributions and return loss calculations are repeated for modified antennas to observe and demonstrate the performance differences. All simulations are verified using HFSS®
software and the results available in the literature.
20
Šmarda, Marek. "Miniaturní anténa pro mobilní aplikace." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2013. http://www.nusl.cz/ntk/nusl-219975.
Full textAbstract:
This work deals with the most famous constructions of planar antennas. The work analyses selected methods of connecting planar antennas' charging with the possibility of impedance adaptation. An important part of the work consists of description of techniques for increasing bandwidth and conversely techniques for reducing the dimensions which are important for the design of planar antennas for mobile devices. The antennas were designed by means of theoretical basis and their properties were examined in the electromagnetic field simulator. The selected antenna model was constructed and its parameters were measured experimentally. The matching circuit for the antenna to tune it to different resonant frequencies was designed and constructed.
21
Tong, Chin Hong Matthew. "System study and design of broad-band U-Slot microstrip patch antennas for aperstructures and opportunistic arrays." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2005. http://library.nps.navy.mil/uhtbin/hyperion/05Dec%5FTong.pdf.
Full textAbstract:
Thesis (M.S. in Combat Systems Technology)--Naval Postgraduate School, December 2005.Thesis Advisor(s): David C. Jenn, Donald L. Walters. Includes bibliographical references (p.83-85). Also available online.
22
Komulainen, M. (Mikko). "Bandwidth enhanced antennas for mobile terminals and multilayer ceramic packages." Doctoral thesis, University of Oulu, 2009. http://urn.fi/urn:isbn:9789514290879.
Full textAbstract:
Abstract
In this thesis, bandwidth (BW) enhanced antennas for mobile terminals and multilayer ceramic packages are presented. The thesis is divided into two parts. In the first part, electrically frequency-tunable mobile terminal antennas have been studied. The first three antennas presented were of a dual-band planar inverted-F type (PIFA) and were tuned to operate in frequency bands appropriate to the GSM850 (824–894 MHz), GSM900 (880–960 MHz), GSM1800 (1710–1880 MHz), GSM1900 (1850–1990 MHz) and UMTS (1920–2170 MHz) cellular telecommunication standards with RF PIN diode switches. The first antenna utilized a frequency-tuning method developed in this thesis. The method was based on an integration of the tuning circuitry into the antenna. The tuning of the second antenna was based on a switchable parasitic antenna element. By combining the two frequency-tuning approaches, a third PIFA could be switched to operate in eight frequency bands.
The planar monopole antennas researched were varactor-tunable for digital television signal reception (470–702 MHz) and RF PIN diode switchable dual-band antenna for operation at four cellular bands. The key advantage of the former antenna was a compact size (0.7 cm3), while for the latter one, a tuning circuit was implemented without using separate DC wiring for controlling the switch component.
The second part of the thesis is devoted to multilayer ceramic package integrated microwave antennas. In the beginning, the use of a laser micro-machined embedded air cavity was proposed to enable antenna size to impedance bandwidth (BW) trade-off for a microwave microstrip in a multilayer monolithic ceramic media. It was shown that the BW of a 10 GHz antenna fabricated on a low temperature co-fired ceramic (LTCC) substrate could be doubled with this technique. Next, the implementation of a compact surface mountable LTCC antenna package operating near 10 GHz was described. The package was composed of a BW optimized stacked patch microstrip antenna and a wide-band vertical ball grid array (BGA)-via interconnection. Along with the electrical performance optimization, an accurate circuit model describing the antenna structure was presented. Finally, the use of low-sintering temperature non-linear dielectric Barium Strontium Titanate (BST) thick films was demonstrated in a folded slot antenna operating at 3 GHz and frequency-tuned with an integrated BST varactor.
23
ZHENG, RUI-GING, and 鄭瑞清. "Slot-coupled microstrip antenna arrays." Thesis, 1989. http://ndltd.ncl.edu.tw/handle/19959493304377062070.
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24
Chang, Hsun-Pin, and 張訓斌. "Microstrip-Fed Microstrip-Slot Antenna for Mobile Handsets." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/21736063275300038658.
Full textAbstract:
碩士國立臺灣大學
電信工程學研究所
97
A new planar multiband antenna with a low antenna height less than 0.06 λ/4 is proposed for moblie handset applications. The antenna comprises two half-wave dipole antennas and two slot antennas. It is fed by a microstrip line which couples the two half-wave strip dipole antennas and two tapered slot antennas on the ground plane. Our design can cover 10 bands including GSM850/GSM900/GSM1800/GSM1900/UMTS/GPS for cellular communication systems, WiMAX2.6/3.5/WLAN2.4/5 GHz for wireless network applications, and the navigation GPS system. The resonant frequency of the antenna can be adjusted by simply changing the lengths of the tuning stub, the monopole slot, and the strip dipole at their respective fundamental resonances. The design principles are simple, the cost is relatively inexpensive, and the fabrication due to its simple 2-dimensional geometry. The radiating elements and the ground plane are located on both sides of the substrate. The whole area of the proposed antenna has dimensions of only 40mmx16mm , which is small enough to fulfill the requirement of the cellular phone.
25
Huang, Tzung-Fang, and 黃宗訪. "CPW-fed slot and microstrip antenna analysis and slot antenna array design." Thesis, 1999. http://ndltd.ncl.edu.tw/handle/15328082494886303293.
Full textAbstract:
博士國立臺灣大學
電機工程學研究所
87
Slot and slot-coupled patch antennas fed by the coplanar waveguide are investigated by using the full-wave analysis based on the Galerkin''s moment method in the spectral domain approach in this dissertation. The coupling slot is etched on the conducting plane of the coplanar waveguide and placed in the direction perpendicular to the transmission line. The equivalent magnetic currents in the coupling slot and in the slots of the coplanar waveguide are all expanded by the subsectional rooftop basis functions, while the equivalent surface electric current density on the microstrip antenna is represented by the entire domain basis functions if necessary. These equivalent currents are solved by the full-wave analysis using the Galerkin weighting procedure, and the reflection coefficient is extracted from the magnetic current distribution on the coplanar waveguide utilizing the matrix pencil technique. All the theoretical results are verified by the measurements and the comparisons show a good agreement between them. Investigation begins with a wide slot antenna fed by a coplanar waveguide. To model the wide slot accurately, the transverse magnetic current component is introduced and more than one longitudinal components are used across the slot. With this study, we can realize how to model the equivalent magnetic current to get a good agreement between theory and experiment. The variations of the characteristics of the inductive or capacitive slot antennas with parameters such as the slot width, slot length, and center strip width of the coplanar waveguide are presented and their corresponding variations in the bandwidth and the resonant frequency are also discussed. The spectral domain Green''s functions and the method of Stationary Phase are also used to calculate the front-to-back radiated power ratio for the CPW-fed slot antenna on a single dielectric substrate. A very simple formulation for the front-to-back radiated power ratio is obtained by assuming that the substrate and metalization is infinite in extend. With this formula, the substrate thickness and dielectric constant can be chosen and designed properly for CPW-fed slots. The same research for the inductive and capacitive patch antenna fed by the coplanar waveguide are also studied in this dissertation. There are more variable parameters such as the slot width, slot length, patch width, and patch length for us to design the patch antenna. The variations of the bandwidth and the resonant frequency with different parameters are also compared to each other. Finally, a simplified procedure for designing the slot antenna array excited by a coplanar waveguide is proposed. Moment method analysis and matrix pencil approach are adopted to calculate the scattering parameters and hence the self-admittance of each slot. The mutual admittances between the slots are calculated from the formulas derived for the complementary strip dipoles based on the reciprocity theorem and via Booker''s relation. Then the transmission line theory is used to calculate the input impedance of the array, and an iterative process is employed to obtain a matched design for a desired slot voltage distribution. A four-element slot array is fabricated and measured using this design procedure. Calculated results are in good agreement with measurements.
26
Li, YiWei, and 李翊瑋. "Analysis and Design of Microstrip Slot Loop Antenna." Thesis, 2001. http://ndltd.ncl.edu.tw/handle/93503038327963038285.
Full textAbstract:
碩士淡江大學
電機工程學系
89
Microstrip antennas have the advantages of light weight, small size and low profile and had found wide applications in various EM areas in this two decades. In this thesis, the radiation characteristics of microstrip square slot loop antenna are investigated in details. Various compact square slot loop antennas of a wavelength and/or half wavelength are designed. These antennas can radiate in broadside and act in resonant mode, hence, they usually have limited impedance bandwidth. Several linearly polarized (LP) antennas fed by stripline and/or microstrip line are designed to operate in the ISM bands. Without external polarizer, the LP antennas can be converted into circularly (CP) polarized antennas by introducing some unsymmetrical elements. Three compact CP slot loop antennas are designed by introducing a center slot or shunt side stubs or corner stubs and tuning the feeding probe carefully. The details of the antenna structures and the radiation characteristics are listed.
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He, Jeng-Shiou, and 何政修. "Dual-band Broadband Annular-ring Slot Microstrip Antenna." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/d99hnu.
Full textAbstract:
碩士中華技術學院
電子工程研究所碩士班
94
A dual-band broadband annular-ring slot microstrip antenna is designed. Its structure is simple. This antenna is analyzed and optimized by using the IE3D software. The annular-ring slot and coupled microstrip feed-line are built on the FR4 printed board. The two resonant frequencies of the proposed antenna are decided by the redius of the annular-ring slot. The prototype are fabricated and measured. The two resonant frequencies are 2.4GHz and 5.8GHz. At 2.4GHz, input impedance bandwidth is23.4% for the S11 < -10 dB, with the peak gain on the order of 8.6dBi. At 5.8GHz, input impedance bandwidth is 13.7% for the S11 < -10 dB, with the peak gain on the order of 14dBi. It is suitable for WLAN applications.
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Lin, Jun-Hong, and 林峻宏. "The Study of Circular Slot Dual-band Microstrip Antenna." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/77a3g5.
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Fu-Mao, Hsieh, and 謝馥懋. "The Design of Microstrip-Line-Fed Printed Slot Antenna." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/74375620362534848658.
Full textAbstract:
碩士南台科技大學
電子工程系
93
The novel designs of printed slot antennas for broadband characteristic have been investigated in this thesis. About this thesis, the designs of printed slot antennas all adopt the method of microstrip-line-fed, they can be classified into two main types of microstrip-line-fed isosceles triangular slot antenna and rectangular slot antenna, and impedance bandwidth of these proposed designs can achieved 77% and 104%, respectively. To begin with, the microstripline feed isosceles triangular slot antenna for broadband operation, the proposed antenna with a small rectangular slot of dimensions L×W, loaded on vertex of the isosceles triangular slot and centered above the microstrip feed line. Under the new structure, the proposed antenna leads to the advantages of broadband, high antenna gain and good co-polarization level. Next, to base on the broadband design of the isosceles triangular slot, we design a structure of rectangular slot antenna with a small trapezoid slot and to perform the purpose of broadband operation. Naturally, we focus on the characteristics of impedance matching, radiation patterns and antenna gain to analyze and study, too.
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shih, han-rong, and 施漢嶸. "Suppression of Reflected Wave of a short Microstrip Leaky-Wave Antenna By Utilizing A Microstrip-Fed Slot Antenna." Thesis, 2001. http://ndltd.ncl.edu.tw/handle/35153849634450751795.
Full textAbstract:
碩士國立交通大學
電信工程系
89
In this thesis, the suppression of the reflected wave of microstrip leaky wave antenna is studied. A microstrip-fed slot antenna is integrated on the backside of the microstrip leaky wave antenna (MLWA) in order to suppress the reflected wave and leak the residual power. Three types of microstrip-fed slot antenna have been designed, which are: one wavelength slot antenna, microstrip-fed first higher-order mode slot antenna and microstrip-fed folded slot antenna. The above antennas are designed at X-band. The two different antenna modes are excited at the top and bottom of a microwave substrate. The microstrip-folded slot antenna array is designed at the backside of a microwave substrate. At the top plane of a microwave substrate, the leaky wave antenna is frequency-dependent scanning and at the backside the microstrip-folded slot antenna array is scanning by different phase feeding. This circuit has the ability of the vertical and horizontal scanning and is constructed in a single-layer microwave substrate.
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Lin, Lawrence, and 林師銓. "Design of CPW-Fed Slot-Loaded Dual-Band Microstrip Antenna." Thesis, 2002. http://ndltd.ncl.edu.tw/handle/31017310219036349225.
Full textAbstract:
碩士國立臺灣科技大學
電子工程系
90
This thesis presents the design of a slot-loaded microstrip antenna fed by a coplanar waveguide which provides dual-frequency operation by means of two narrow slots close to the patch edges. The two narrow slots strongly modify the current distribution of a patch antenna at the resonance. We investigated polarization planes、radiation properties and the effect of slot size, of the two operating frequencies, and use cavity model to calculate operating frequencies. Finally, we implemented a 2.4G Hz microstrip antenna fed by a coplanar waveguide and a slot-loaded dual-frequency microstrip antenna fed by a coplanar waveguide at 2.4G Hz and 2.9G Hz. The characteristics of simulation and the measured results of return loss and radiation pattern are consist with the results from theory and simulation.
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GIA, LA-WEI, and 茄拉威. "An analysis method for the linear microstrip slot antenna array." Thesis, 1989. http://ndltd.ncl.edu.tw/handle/44108068097720435977.
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meng-shan, Chiang, and 蔣孟珊. "Study on active H-slot/T-coupled circular microstrip antenna." Thesis, 2004. http://ndltd.ncl.edu.tw/handle/80240554413355985697.
Full textAbstract:
碩士國防大學中正理工學院
電子工程研究所
92
In this thesis, using T-coupled feed line, H-slot, dual-polarized techniques and active integrated antenna to improve the conventional circular microstrip antenna, and applied for four 2.4GHz ISM-Band antennas. First, we make a study of circular microstrip antenna. Adding T-coupled feed line to achieve impedance matching. Then, we can improve the bandwidth and radiation gain of antenna by using H-slot to design an H-slot/T-coupled circular microstrip antenna. It has wideband and high radiation gain. Second, we can design a dual-polarized antenna by the symmetrical structure of H-slot/T-coupled circular microstrip antenna and dual-polarized technique. It has capability to receive and transmission. In application, we can design an active H-slot/T-coupled circular microstrip antenna and repeater active integrated antenna by using active integrated antenna’s technique.
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YU-TA, CHIEN, and 簡鈺達. "Implement of a Compact CPW-fed Square-Ring-Slot Coupled Microstrip Antenna." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/00540314211632209669.
Full textAbstract:
碩士正修科技大學
電子工程研究所
93
In this paper, We have presented about the compact CPW-fed square-ring-slot coupled microstrip antenna. We have investigated the characteristics of the proposed compact CPW-fed square-ring-slot coupled microstrip antenna. The properties of return losses, frequencies and radiation pattens have shown in this thesis. We have also discussed the effects on slot-ring and ground-plane size of the proposed antenna. The theoretical results have obtained from simulation software, HFSS. The software package HFSS is based on the differential equation and the Finite Element Methods. And, the experimental results have been verified by the HFSS simulation.
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Cheng, Hao, and 鄭浩. "Design of Dual-Band Microstrip Patch Antenna with Dual Cross-Slot for WLAN Application." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/h75xu8.
Full textAbstract:
碩士景文科技大學
電子工程系電腦與通訊碩士班
102
In the thesis, we present Dual-Band Microstrip Patch Antenna with a Double Cross-Slot employed Microstrip line feeding as well as slot design to enhance impedance matching and Cross-Slot to increase 5GHz resonance frequency.We use short area to fill the turning point of slots or short line to the centers of slots in order to enhance current paths. Simultaneously, aforesaid methods can change current at both sides of slot from reverse to the same direction so as to achieve antenna radiation gain.Dual-Band Microstrip Patch Antenna with a Double Cross-Slot is designed by one forth bandwidth of 2.45GHz to apply to WLAN 2.45GHz/5GHz dual-band directive antenna. In regard to antenna structure,Its dimension is 63mm x 72mm x 7.6mm,Dual-Band Microstrip Patch Antenna with a Double Cross-Slot design possesses the strength of power centralization and long distance transmission, which antenna design is more suitable for WLAN product application, e.g. wireless routers.
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Lin, Pei Ying, and 林佩穎. "The Influences of Feeding Via Upon the Bandwidth of Planar Slot Antenna Excited by Microstrip." Thesis, 2004. http://ndltd.ncl.edu.tw/handle/18740370482614134810.
Full textAbstract:
碩士淡江大學
電機工程學系
92
In this thesis, the characteristics of the folded slot antennas and the influences of the feeding via upon the slot antenna bandwidth are investigated in details. The antennas studied are polarized and excited by a 50Ω microstrip line, and are linearly polarized. There are two kind of folded slot antennas discussed, in the thesis: one is single folded slot antenna and the other is double folded slot antenna. As compared to a simple slot antenna, it is found that the bandwidth of a single folded slot antenna is slightly wider. In addition, double folded slot antennas can provide significantly wide bandwidth up to 34%, which serves as a good candidate for UWB application. The metallic contact between the microstrip line and the ground plane thought the via hole forms a short-circuit. The feeding via hole can reduce the cross polarization and the antenna size. In this thesis , all antennas fed by microstrip line are designed to operate in the ISM bands.
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Holland, Steven S. "Miniaturization of Microstrip Patch Antennas for Gps Applications." 2008. https://scholarworks.umass.edu/theses/120.
Full textAbstract:
The desire to incorporate multiple frequency bands of operation into personal communication devices has led to much research on reducing the size of antennas while maintaining adequate performance. GPS is one such application, where dual frequency operation, bandwidth and circular polarization pose major challenges when using traditional miniaturization techniques. Various loading methods have been studied to reduce the resonant frequency of the antenna – high permittivity dielectric loading, slot loading and cavity loading – while examining their effects on bandwidth and gain. The objective of this thesis is to provide guidelines on what is achievable using these miniaturization methods and insight into how to implement them effectively.
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Alibakhshikenari, M., B. S. Virdee, C. H. See, Raed A. Abd-Alhameed, F. Falcone, and E. Limiti. "Super-Wide Impedance Bandwidth Planar Antenna for Microwave and Millimeter-Wave Applications." 2019. http://hdl.handle.net/10454/17098.
Full textAbstract:
YesA feasibility study of a novel configuration for a super-wide impedance planar antenna is presented based on a 2 × 2 microstrip patch antenna (MPA) using CST Microwave Studio. The antenna comprises a symmetrical arrangement of four-square patches that are interconnected to each other with cross-shaped high impedance microstrip lines. The antenna array is excited through a single feedline connected to one of the patches. The proposed antenna array configuration overcomes the main drawback of conventional MPA with a narrow bandwidth that is typically <5%. The antenna exhibits a super-wide frequency bandwidth from 20 GHz to 120 GHz for S11 < −15 dB, which corresponds to a fractional bandwidth of 142.85%. The antenna’s performance of bandwidth, impedance match, and radiation gain were enhanced by etching slots on the patches. With the inclusion of the slot, the maximum radiation gain and efficiency of the MPA increased to 15.11 dBi and 85.79% at 80 GHz, which showed an improvement of 2.58 dBi and 12.54%, respectively. The dimension of each patch antenna was 4.3 × 5.3 mm2 . The results showed that the proposed MPA is useful for various existing and emerging communication systems such as ultra-wideband (UWB) communications, RFID systems, massive multiple-output multiple-input (MIMO) for 5G, and radar systems.
This work was partially supported by the Innovation Program under grant agreement H2020-MSCA-ITN-2016 SECRET-722424 and financial support from the UK Engineering and Physical Sciences Research Council (EPSRC) under grant EP/E022936/1.
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HUANG, ZHANG-XIU, and 黃章修. "Slot-coupled double-layered microstrip antennas." Thesis, 1992. http://ndltd.ncl.edu.tw/handle/64257671893454577094.
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廖彥傑. "Reconfigurable Microstrip-fed Slot Antennas Design." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/49416155347563641699.
Full textAbstract:
碩士逢甲大學
電機工程學系
101
This thesis focuses on reconfigurable slot antenna research, and two types of reconfigurable slot antennas are proposed. To achieve frequency or polarization diversity for the proposed slot antenna, pin-diodes were used for switching purposes. A reconfigurable slot antenna with switchable polarization is initially proposed in this thesis. The proposed antenna is comprised of a square-shaped radiating element loaded with an eccentric circular slot. It is fed by a microstrip feed line, and can excite TM11 mode. In order to generate circularly polarization (CP) radiation, two identical perturbed circular shaped slot are loaded below the eccentric ring-shaped slot at -20° and 20° position with respect to the –Y axis. By switching the pin-diodes embedded into the slot, the proposed antenna can switch between left hand circular polarization (LHCP), right hand circular polarization (RHCP), and linear polarization (LP). Besides possessing the ability to switch between the three polarizations, the advantages of this proposed antenna also include compact size (50 × 50 mm2), simple DC bias circuit, and the ability to cover the required operating band (2400-2480 MHz) for WLAN 2.4 GHz applications. The second proposed antenna is a reconfigurable slot antenna design with switchable frequency. In this design, a circular slot is first embedded into a square-shaped ground plane; follow by embedding a semi-circular patch into the slot, forming a semi-circular slot structure with the bottom section analogous to a halve-annular ring slot. Here, a meandered stub is also loaded above the semi-circular patch, and the proposed antenna is fed by a microstrip line. To achieve frequency reconfiguration, three pin-diodes are embedded along the meandered stub. By switching these three pin-diodes in a certain sequences, the electric field distribution along the halve-annular ring slot will be affected, and four resonant modes (2.66, 2.94, 3.52, and 4.4 GHz) can be separately excited. Therefore, operating bands between 2.6 and 4.7 GHz can be controlled by the proposed antenna. Compared with the first proposed antenna, the latter has also exhibited small size characteristics (50 × 50 mm2) and simple DC bias circuit.
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TSAI, RUENN-BO, and 蔡潤波. "ANALYSIS OF CYLINDRICAL PRINTED SLOT AND SLOT-COUPLED MICROSTRIP ANTENNAS." Thesis, 1995. http://ndltd.ncl.edu.tw/handle/81909879675081363094.
Full textAbstract:
博士國立中山大學
電機工程研究所
83
Rigorous analysis of printed slot and slot-coupled microstrip antennas on a cylindrical surface is presented. The study is per- formed by using the full-wave analysis incorporating with the exact Green''s-function formulation in the spectral domain, and Galerkin''s moment-method is applied to calculate the numerical results. The curvature effects on the characteristics of both cylindrical prinred slot and slot-coupled microstrip antennas are major subjects of the present study. To begin with, the propagation constant and characteristic impedance of the cylindrical microstrip line mounted inside a ground cylinder are first investigated. Both the quasi-static approach and the full-wave analysis are used to solve the problem . Numerical results showing the curvature effects on the propaga- tion constant and characteristic impednce are presented. A compu- tation algorithm to facilitate the numerical calculation is also briefly described. Next, a microstrip-line-fed cylindrical printed slot antenna is studied. The resonant electric field in the slot is expanded using a set of piecewise sinusoidal(PWS) expansion functions. Reciprocity technique is employed to account for the equivalent series impedance introducted by the slot discontinuity on the microstrip line . Finally, a microstrip-line -fed slot-coupled cylindrical rect- angular microstrip patch antenna ia analyzed. The theoretical approach for this analysis is similar to tht used for the printed slot antenna. The unknown resonant currents on the microstrp patch are expanded using a set of entire-domain basis functions, while the electric field in the nonresonant slot is represented by a single PWS mode due to its smaller size. Based on the reci- procity method, the equivalent series impedance, introduced by the coupling slot and the resonant patch, seen by the microstrip line can be calculated.
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Nguyen, Hung Tien. "Miniaturizing microstrip patch antennas by slot loading." 2006. http://hdl.handle.net/1993/20837.
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Yi-Chin, Huang, and 黃宜勤. "MICROSTRIP-FED SLOT ANTENNAS ON UNIAXIAL SUBSTRATES." Thesis, 1998. http://ndltd.ncl.edu.tw/handle/27475967693774514347.
Full textAbstract:
碩士大同工學院
電機工程研究所
86
This thesis is a research of theoretical investigation and numerical results for a microstrip-fed slot antenna on an uniaxial anisotropic substrate by using the full-wave analysis. The uniaxial Green's function in the spectral form is first derived. Once the Green's function is obtained, the integral equations are solved by the moment method procedure. In this method, the piecewise sinusoidal (PWS) functions are selected as the basis functions and the Gaussian-Legendre integral rule is applied to reduce the CPU time. Finally, numerical results show the effects upon the resonant frequency of microstrip-fed slot antenna on unaxial anisotropic substrates.
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Chen, Ming-Huang, and 陳明煌. "Studies of Broadband Slot-Coupled Microstrip Antennas." Thesis, 1999. http://ndltd.ncl.edu.tw/handle/61453783316031299094.
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Sze, Jia-Yi, and 施家頤. "BANDWIDTH-ENHANCEMENT DESIGNS OF SLOT-LOADED RECTANGULAR MICROSTRIP ANTENNAS." Thesis, 2001. http://ndltd.ncl.edu.tw/handle/39979534891750933034.
Full textAbstract:
博士國立中山大學
電機工程學系研究所
89
The bandwidth-enhancement characteristics of slot-loaded rectangular microstrip antennas constructed on a thin microwave substrate have been investigated in this dissertation. The primary design process about this topic is demonstrated. Firstly, a new antenna design idea is provided from pre-determined antenna design specifications or obtained antenna performances from the previous antenna design, which lead to a novel antenna configuration. From the results of the simulation software IE3DTM, the characteristics of this new antenna configuration are obtained and compared with the experimental results. The antenna configuration is also modified to achieve a final optimal design from the comparison results. The study of the single-feed dual-frequency rectangular microstrip antenna with a pair of bent slots is first presented. By embedding properly-designed slots on a rectangular microstrip patch, the impedance characteristics of this antenna design have been effectively changed to exhibit dual-resonant behavior, which result in the excitation of two adjacent resonant modes with similar radiation characteristics. Furthermore, the two resonant modes can be excited at frequencies very close to each other to form a wider operating bandwidth by embedding additional perturbation slots. Four successful antenna designs with different embedded-slot shapes for bandwidth enhancement have been implemented and discussed in this dissertation.
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張明軒. "Study of Microstrip-fed Ring Slot Antennas with Harmonic Suppression." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/83282950870305764792.
Full textAbstract:
碩士逢甲大學
電機工程所
101
Recently, it is a pre-requisite requirement for hand-held communication products to possess the advantages such as light in weight, compact size and low manufacturing cost. To satisfy these requirements, a single structure design that comprised of an antenna integrated with the front-end circuit of the communication system is presently attracting many attentions. However, higher-order resonant modes excited by the antenna can cause EMI problems on the active circuit, which lead to degrading the performances of the system. Hence, the common solution to solve this problem is to use low-pass or band-pass filter. However, this method will increase the circuit size, manufacture cost, and insertion loss. To resolve these disadvantages, harmonic suppression antenna design is now an attractive topic of research interest. This thesis are divided into two parts, the first part presents a harmonic suppression annular-ring slot antenna that operates in the 2.4 GHz WLAN band. Here, the inverted U-shaped ground defect structure (DGS) is used as a low-pass filter, and it is integrated into an annular-ring slot antenna, so that it can suppress unwanted higher-order resonance modes (return loss < 3 dB) within the frequencies range between 3 and 9 GHz. In the second part of this thesis, a circularly polarized (CP) annular-ring slot antenna with harmonic suppression is proposed. It is noteworthy that this CP annular-ring slot antenna with harmonic suppression design has never been discussed or reported elsewhere in the open-literature. In this design, a novel CP annular-ring slot antenna operating at WLAN 2.4 GHz is initially studied with axial ratio (AR) bandwidth of 210 MHz (8.79%). Here, the main advantage of this CP slot antenna design is that during the process of integration with the harmonic suppression structure (DGS) discussed in the part 1, there is no need to alter the antenna’s feed terminal. By integrating the DGS into the proposed CP annular-ring slot antenna structure, a 2.4 GHz WLAN antenna with wide harmonic suppression bandwidth between 3 and 10 GHz is achieved, and the AR bandwidth is 223 MHz (9.33%).
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HUANG, SHENG-YANG, and 黃勝暘. "Microstrip-Fed Circular Ring Slot Antennas with Wideband Harmonic Suppression." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/q7wcns.
Full textAbstract:
碩士逢甲大學
電機工程學系
106
Recently, it is a prerequisite requirement for hand-held communication products to possess the advantages such as light in weight, compact size and low manufacturing cost. To satisfy these requirements, a single structure design that comprised of an antenna integrated with the front-end circuit of the communication system is presently attracting many attentions. However, high order harmonic modes excited by the antenna can cause electromagnetic interference (EMI) problems on the active circuit, which lead to degrading the performances of the system. Hence, the common solution to solve this problem is to use low-pass or band-pass filter. However, this method will increase the circuit size, manufacture cost, and insertion loss. To resolve these disadvantages, antenna design with harmonic suppression is now an attractive topic of research interest. This thesis is divided into two parts, the first part presents a wide band harmonic suppression circular ring slot antenna that operate in the 2.45 GHz wireless local area network (WLAN) band. Here, a novel stepped impedance resonator (SIR) structure as a low-pass filter and the open stubs (OS) as a band-stop filter are integrated into the circular ring slot antenna, so that it can suppress unwanted high order harmonic modes (return losses < 3 dB) within the frequencies range from 3 to 20 GHz. Also, it is well known the conventional ring slot antenna is a half wavelength resonator whereas the SIR structure is not only regarded a LPF but also can reduce the size of antenna about 15 % by its electrical characteristic. In the second part of this thesis, a triple-band circular ring slot antenna with wideband harmonic suppression is proposed. It is noteworthy that this triple-band circular ring slot antenna with wideband harmonic suppression design has no effect on the fundamental resonate mode with etching extra slots, so that can operate in the 2.4 GHz, 5.2 GHz and 5.8 GHz WLAN application.
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Chen, Richard H., and 陳彥池. "Miniaturized Design of Microstrip-Fed Slot Antennas for MIMO System Applications." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/45343314349670570238.
Full textAbstract:
碩士臺灣大學
電信工程學研究所
98
In this thesis, a miniaturized design of microstrip-fed slot antennas is presented. By adding C-shaped rings inside the slot, the antenna size is reduced and dual-band characteristic may also be obtained. The C-shaped rings are used as inductive loadings to enhance the slow-wave effects leading to the effective propagation wavelength and the required antenna resonant lengths can be shorten. The mechanism, location in the slot, and dimensions of C-shaped rings are extensively studied and the optimization is made to effectively reduce the antenna size. Besides antenna size reduction, the C-shaped rings can produce an additional impedance-matched deep so that the impedance bandwidth can cover the dual-band specification of IEEE 802.11a/b/g/n. Taking advantage of size reduction by using C-shaped rings in slot antennas, a four-element open-slot diversity antenna for MIMO system application is also proposed. It shows good pattern and polarization diversity characteristics. The system performances are studied by calculating the correlation coefficients, mean effective gains, and effective diversity gains.
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Tseng, Wen-Jen, and 曾文仁. "Slot-Coupled Microstrip Antennas with Single or Multiple Ports : Designs and Applications." Thesis, 1998. http://ndltd.ncl.edu.tw/handle/04919977414849308633.
Full textAbstract:
博士國立交通大學
電信工程系
87
In this thesis, we propose and analyze several slot-coupled microstrip antennas with single or multiple ports for applications in active integrated antennas, remote identification, and communications. These antenna structures consist of (a) adding a second port to the traditional slot-coupled microstrip antenna to obtain a brand-new two-port antenna, (b) arranging several slot-coupled microstrip antennas to achieve a planar retrodirective antenna array, and (c) using two slot antennas constructed with the Wilkinson power divider configuration to form a novel dual circularly polarized antenna. To analyze these antenna structures of slot coupling feed, Galerkin''s method of moments together with a mixed-potential integral equation (MPIE) was used. Also, the microstrip feed line was modeled as a waveguide for simplifying the problems. The two-port slot-coupled microstrip antenna contains a feeding port and a coupling port. Most of the incident power coming from the feeding port is radiated by the microstrip patch, and part of the power enters to the coupling port. A feedback antenna oscillator was designed by applying the present structure where it served as a feedback resonator and a radiator at the same time. The oscillation was stable and with a clean spectrum at the frequency of 9.79 GHz which was only 0.2% different from the design one. An effective isotropic radiated power (EIRP) of 39 mW was achieved. The measured cross-polarized fields were at least 15 dB lower than the co-polarized ones. Next, a planar antenna array reflector with retrodirectivity in both the E-plane and the H-plane is analyzed and demonstrated at X-band. The reflector consists of six pairs of symmetrically located slot-coupled patch antennas paired by microstrip lines. The total reflected field from the reflector is separated into three primary components, that is, the reradiation field from the patch antennas (RFPA), the scattering field from the patch antennas (SFPA), and the scattering field from the ground plane (SFGP). The first two components are calculated by using the method of moments and the last one is by the physical optics (PO) method combined with the method of equivalent currents (MEC). By tuning the microstrip-line lengths, the total reflected field contributed by the three components is designed to possess a broad-beamed pattern in both the E-plane and the H-plane. The measured reflected-field patterns of the fabricated reflector show good agreement with the designed ones. Finally, an offset-fed slot antenna was used to replace the lumped resistor in the equal-split Wilkinson power divider, and a dual CP slot antenna operating at S-band was designed and fabricated experimentally. The antenna possessed a return loss bandwidth of 39.3%, an isolation bandwidth of 10.3% for VSWR < 2, and a 3-dB axial ratio bandwidth of 28%.
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Chen, Ya-Shin, and 陳雅欣. "Microstrip Antenna Miniaturization Design Using Slow Wave Property of EBG Structure." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/26243683954337952726.
Full textAbstract:
碩士國立臺灣大學
電機工程學研究所
97
In wireless communication systems the signal transmission always relies on antennas. With the advance in technology nowadays, the appearances of miniaturized electronic products are more frequent. Most of these communication products are operating at lower frequency band such as WLAN which uses the specification of 802.11b and 802.11g, Bluetooth system as well as GSM900 are operating at lower frequency band below a few GHz. In order to integrate with miniaturized wireless devices, we have proposed an EBG integrated patch antenna for reducing antenna size. With numerous advantages, the conventional microstrip antennas can be employed in many devices but are not proper for compact systems which have low operation frequency. The good radiation property of a patch antenna integrated with EBG structure on a dielectric slab can still be maintained. The simulation and measurement have been developed for verification. Furthermore, we have an analysis about EBG parameters and propose a design procedure for better EBG patch antenna design. The comparisons between a conventional and EBG patch antenna have also discussed in this thesis. The overall performance is validated in the simulation and measurement.