Дисертації з теми "APERTURE COUPLED ANTENNA"
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1
Civerolo, Michael Paul. "Aperture Coupled Microstrip Antenna Design and Analysis." DigitalCommons@CalPoly, 2010. https://digitalcommons.calpoly.edu/theses/300.
Повний текст джерелаАнотація:
A linearly-polarized aperture coupled patch antenna design is characterized and optimized using HFSS antenna simulation software. This thesis focuses on the aperture coupled patch antenna due to the lack of fabrication and tuning documentation for the design of this antenna and its usefulness in arrays and orthogonally polarized communications. The goal of this thesis is to explore dimension effects on aperture coupled antenna performance, to develop a design and tuning procedure, and to describe performance effects through electromagnetic principles.
Antenna parameters examined in this study include the dimensions and locations of the substrates, feed line, ground plane coupling slot, and patch. The operating frequency, input VSWR, percent bandwidth, polarization ratio, and broadside gain are determined for each antenna configuration.
The substrate material is changed from RT Duroid (material in nominal HFSS design) to FR4 due to lower cost and availability. The operating frequency is changed from 2.3GHz (specified in nominal HFSS design) to 2.4GHz for wireless communication applications. Required dimensional adjustments when changing substrate materials and operating frequencies for this antenna are non-trivial and the new design procedure is used to tune the antenna.
The antenna is fabricated using 59mil thick double and single sided FR4 boards joined together with double sided 45mil thick acrylic tape. The antenna is characterized in an anechoic chamber and experimental results are compared to theoretical predictions. The results show that the new design procedure can be successfully applied to aperture coupled antenna design.
2
Zubir, Farid. "Direct integration of push-pull amplifier and aperture coupled antenna." Thesis, University of Birmingham, 2016. http://etheses.bham.ac.uk//id/eprint/6454/.
Повний текст джерелаАнотація:
The work described in this thesis concerns the integration of push-pull class B amplifier and antenna modules. Push-pull class B is well-known with its fruitful advantages of using differential feeding technique, resulting in low distortion, reasonably high efficiency and high output power. Meanwhile, the antenna module in this work is adapted from the aperture-coupled antenna structure due to its degree of freedom to control the variables which provide the best possible topology that could be realised in system on chip or system in package. More generally, the variables allow good coverage of the Smith Chart so that a wide range of odd-mode matching requirements could be met, for different devices and bias condition of a given transistor. The approach also offers additional filtering up to 3rd harmonic in that it comprises identical harmonic traps on both sides of the aperture using resonant stubs to form bandstop filters, which reduce the ripples at the output waveforms, giving them a significant advantage of neat and tight integration of a push-pull transmitting amplifier.
3
Zivanovic, Bojana. "Series-Fed Aperture-Coupled Microstrip Antennas and Arrays." Scholar Commons, 2012. http://scholarcommons.usf.edu/etd/4425.
Повний текст джерелаАнотація:
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.
4
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.
Повний текст джерелаАнотація:
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.
5
Vlasits, Tamas. "Modelling and application of a cross-aperture coupled single feed circularly polarised patch antenna." Thesis, Northumbria University, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.245262.
Повний текст джерела
6
Liu, Lei. "Investigation of aperture coupled microstrip antenna to obtain a high efficient active integrated antenna by using Class F and Inverse Class F power amplifiers." Thesis, Northumbria University, 2013. http://nrl.northumbria.ac.uk/21425/.
Повний текст джерелаАнотація:
In wireless communications and radar systems, there are requirements for high efficiency, small size, low cost, and wide bandwidth of transmitter front –end usage for commercial and also military applications. Active integrated antenna (AIA) could satisfy almost all the requirements. The overall objective of the proposed research is to model, optimise, and design a compact and high efficient AIA using an aperture coupled microstrip antenna (ACMA) by integrating with a power amplifier (PA). Research on ACMA has been focused on the transmissions line (TL) model (TLM) and full wave electromagnetic (EM) model analysis. The full wave investigation is rigorous and elegant but because the dimension of the physical model and the value of the circuit elements are interdependent, the design of the antenna is still difficult. TLM analysis has lower accuracy but easier to analysis and optimise than full wave EM model analysis. To increase the accuracy, the challenge is the coupling ratios between feed/slot, and slot/patch where no unique solution at the moment exists. In this thesis, a novel and simplified method has been produced to investigate these ratios using Scattering (S) parameters. A dual frequency ACMA has been designed to verify these results. Research on the class F and inverse class F PAs is carried out by a novel and simplified load/pull method. A new design method of harmonic load matching network has been presented using lump elements and TLs. Both linear and nonlinear modelling has been investigated. High power added efficiency (PAE) and high gain which are up to 60% and 12dB have been obtained. Finally AIAs have been produced based on previous investigation on class F, inverse class F PAs and a broadband circular polarized ACMA design with 350 MHz bandwidth and 8.5 dB gain at 2 GHz.
7
Okuducu, Yusuf. "Dual Band Microstrip Patch Antenna Structures." Master's thesis, METU, 2005. http://etd.lib.metu.edu.tr/upload/2/12606859/index.pdf.
Повний текст джерелаАнотація:
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
8
Bílek, Ondřej. "Flíčkový reflektor s elektronickým řízením směrové charakteristiky." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2017. http://www.nusl.cz/ntk/nusl-316447.
Повний текст джерелаАнотація:
The diploma thesis is aimed to design, optimize, produce and subsequently measure the properties of the reflector with the electronic steering direction for the frequency of the 24,125 GHz band ISM. The problem chosen is solved by a group of voltage-controlled varicaps. The reflector consists of a matrix of two rows, each containing 3 cells. The reflector was designed by full-wave software CST Microwave Studio 2015.
9
Liyakath, Riaz Ahmed. "Reconfigurable Antenna and RF Circuits Using Multi-Layer Stretchable Conductors." Scholar Commons, 2012. http://scholarcommons.usf.edu/etd/4130.
Повний текст джерелаАнотація:
The growth of flexible electronics industry has given rise to light-weight, flexible devices which have a wide range of applications such as wearable electronics, flexible sensors, conformal antennas, bio-medical applications, solar cells etc. Though several techniques exist to fabricate flexible devices, the limiting factors have been durability, cost and complexity of the approach. In this research, the focus has been on developing stretchable (flexible) conductors using a multi-layer structure of metal and conductive rubber. The stretchable conductors developed using this approach do not lose electrical connection when subjected to large strains up to 25%. Also, the conductivity of the conductive rubber has been improved by ~20 times using the multi-layer approach. Furthermore, the multi-layer approach was used to fabricate devices for RF and antenna applications. A flexible micro-stripline was fabricated using the multi-layer approach to study the performance at microwave frequencies up to 5 GHz. It was observed that using an optimal metal and conductive rubber layer structure can help to reduce the loss of the device by 58% and also the device does not get damaged due to bending. In addition to this, an aperture-coupled patch antenna at 3.1 GHz was fabricated using the multi-layer approach to demonstrate reconfigurability. Ideally, the multi-layer patch antennas can be stretched up to 25% which helps to tune the resonance frequency from 3.1 GHz to 2.5 GHz. The multi-layer patch antennas were tested up to ~10% strains to study their radiation properties. It was demonstrated that using an ideal multi-layer structure of metal and conductive rubber layer can help to improve the antenna's peak gain by 3.3 dBi compared to a conductive rubber based antenna.
10
GUGLIANDOLO, GIOVANNI. "Applications of Microwave Resonators to Thermal Metrology." Doctoral thesis, Politecnico di Torino, 2020. http://hdl.handle.net/11583/2849028.
Повний текст джерела
11
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.
Повний текст джерелаАнотація:
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.
12
Filice, Francesco. "Solutions innovantes d'antennes en bande Ku- et Ka- en technologie d’impression 3-D pour la réalisation des réseaux phasés visant des applications 5G et des communications mobiles par satellite." Thesis, Université Côte d'Azur, 2020. http://www.theses.fr/2020COAZ4023.
Повний текст джерелаАнотація:
L'utilisation exponentielle d’applications mobiles entraîne une demande en constante croissance pour des débits de données de plus en plus élevés associées à des solutions de télécommunications mobiles à faible coût. Alors que les réseaux 5G en sont encore à leur début, les télécommunications mobiles par satellite (Sat-Com-On-The-Move) peuvent jouer un rôle central dans cette problématique. La bande passante disponible dans les bandes de fréquences Ku- (10,75-14,5 GHz) et Ka- (18-31 GHz) pour ces applications peut être exploitée afin de fournir une connexion internet globale à haut débit et faible coût. Des entreprises comme SpaceX déploient actuellement de grandes constellations de satellites positionnées sur des orbites terrestres basses et pouvant répondre à ces besoins. Néanmoins, le prix et le facteur de forme des terminaux utilisateurs à réflecteur motorisé existants restent les principaux goulots d'étranglement pour rendre ces technologies abordables à une grande partie de consommateurs. La bande passante opérationnelle atteignable par les éléments rayonnants intégrés à faible profil (i.e. réseaux d’antennes à fentes) étant limité, la plupart des solutions existantes divisent la transmission (Tx) et la réception (Rx) dans deux panneaux rayonnants différents ce qui impose un coût relativement élevé pour les utilisateurs finaux. L'objectif de cette thèse consiste à développer des solutions d'antennes innovantes à faible coût et à large bande, notamment des antennes patch à couplage par fente et des antennes à guides d'ondes nervurés fabriqués avec des circuits imprimés standard (PCB) et par impression 3D en métal. Ces antennes sont censées couvrir la totalité de la bande Ku et Ka afin de permettre la création de terminaux utilisateur Sat-Com-On-The-Move à faible encombrement capables d'effectuer à la fois les fonctions Rx et Tx à l'aide d'un seul panneau antennaire. Une attention particulière est accordée à la possibilité d'intégrer ces éléments rayonnants dans de petits réseaux à utiliser comme cellule unitaire pour la réalisation de plus grands, en envisageant la possibilité d'atteindre les niveaux de gain requis par ce type de télécommunicationsThe increasing use of mobile applications leads to a growing demand for higher data-rates and low-cost mobile telecommunication solutions. While 5G networks are still at their early stages, a central role can be played by the mobile satellite telecommunications (Sat-Com-On-The-Move). The frequency bandwidth available at Ku- (10.75-14.5 GHz) and Ka- (18-31 GHz) bands for these applications can be leveraged in order to provide worldwide, high-speed and low-cost internet connections. Companies like SpaceX are actually deploying large satellite constellations required to work at Low Earth Orbits and offer such services. Nevertheless, the price and the form factor of the traditional motorized reflector-based user terminals remain the main bottlenecks in order to make these technologies affordable to the mass-market consumers. The limited operational bandwidth of the radiating elements integrated in their low-profile alternatives (i.e. slotted waveguide antenna arrays) actually obliges to split transmission (Tx) and reception (Rx) in two different panels, keeping a relatively high cost for the end-users. The objective of this thesis is to develop innovative low-cost and wideband antenna solutions, notably microstrip aperture coupled patch and double ridged waveguide antennas, to be respectively realized by standard Printed Circuit Board (PCB) and metal 3-D printing. These antennas are meant to cover the whole Ku- and Ka- band in order to allow the creation low-profile Sat-Com-On-The-Move user terminals able to perform both Rx and Tx using a single antenna panel. A particular attention is given to the possibility to integrate these radiating element in small arrays to be used as unit cell for the realization of larger ones, envisaging the possibility to achieve the levels of gain required by this kind of telecommunications
13
Robinson, Bryan. "Mathematical modelling of aperture coupled patch antennas with multi-layered superstrates." Thesis, Northumbria University, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.245239.
Повний текст джерела
14
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.
Повний текст джерелаАнотація:
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.
15
Kacar, Merve. "Direct Digital Manufacturing of Multi-layer Wideband Ku-band Patch Antennas." Scholar Commons, 2017. https://scholarcommons.usf.edu/etd/7411.
Повний текст джерелаАнотація:
Design and performance of fully-printed Ku-band aperture coupled patch antennas fabricated by a direct digital manufacturing (DDM) approach that integrates fused deposition modeling (FDM) of acrylonitrile butadiene styrene (ABS) thermoplastic with in-situ micro-dispensing of conductive silver paste (CB028) are reported. Microstrip line characterizations are performed and demonstrate that misalignment of ABS substrate deposition direction with microstrip line micro-dispensing direction can degrade the effective conductivity up to 60% within the Ku-band, and must be taken into consideration in antenna array feed network designs. Specically, over 125 µm thick ABS substrate, RF loss of 0.052 dB/mm is obtained at 18 GHz, demonstrating the feasibility of additively manufactured RF devices within the Ku-band. By varying ABS inll ratios and resorting to multi-layer printing with custom substrate thicknesses, single and stacked patch antennas are designed, fabricated, and characterized with bandwidth performances up to 35%, and radiation efficiencies up to 90%. This extensive utilization of the design flexibilities provided by the direct digital manufacturing (i.e. customized substrate thicknesses, multiple substrates with varying infill ratios, and in-situ micro-dispensing of conductors) distinguishes the present work from the recently reported 3-D printed antennas. Compared to the existing work in literature, the antennas presented within this thesis stand out as being fully printed structures, operating in higher frequency range (i.e. Ku-band), and exhibiting high radiation efficiencies with wide bandwidth performances.
16
Nien-An, Kao, and 高念安. "Active Aperture-Coupled Leaky-Wave Antenna." Thesis, 1999. http://ndltd.ncl.edu.tw/handle/86577771140409809941.
Повний текст джерелаАнотація:
碩士國立交通大學
電信工程系
87
This thesis will investigate the active aperture-coupled leaky-wave antennas and the multi-beam aperture-coupled leaky-wave antenna, including design, fabrication and measurement. To excite the microstrip first higher mode, the aperture-fed structure is utilized and a sequence of covered wire is added in the center of this antenna to suppress the dominant mode. The leaky-wave antenna offers beam-steering capability, high gain and narrow main beam. In addition, the aperture-fed structure reduces the circuit size and offers an excellent shielding between active and radiation elements. We produce two kinds of active aperture-coupled leaky-wave antennas-side-fed with a single main beam and center-fed with a dual-beam. The side-fed one provides a 16°scanning angle in H-plane from 8.97 GHz to 9.5 GHz and its maximum EIRPs are 21.98±1.59 dBm. The center-fed one provides a 20°scanning angle in H-plane from 8.97 GHz to 9.5 GHz and its maximum EIRPs are 18.56±0.33 dBm for the right beam and 18.9±0.13 dBm. Theses antennas are suitable for active phase antenna array applications or other microwave transceiver system. On the other hand, we utilized the aperture-fed leaky-wave antenna to develop a multi-beam antenna. Its transmitting and receiving radiation patterns are observed their scanning angles as 22°and 16°~18°respectively. This antenna has a developmental potential in transmit/receive modules such as smart antenna systems because both modules employ use only one antenna.
17
GAO, YI-TAO, and 高易韜. "Series-fed aperture-coupled microstrip antenna array." Thesis, 1992. http://ndltd.ncl.edu.tw/handle/89241900093145098936.
Повний текст джерела
18
Huang, Chien-Hsiung, and 黃建雄. "PARALLEL APERTURE-COUPLED DUAL-BAND CIRCULARLY POLARIZED ANTENNA." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/67838891277471199597.
Повний текст джерелаАнотація:
碩士大同大學
通訊工程研究所
99
This thesis presents a parallel feed line which couples diamond-shaped slot to ring and cross-slot to patch. The feed line is used to feed the two parts in parallel. Then, the structure can easily be operated as a dual-band circularly polarized antenna to cover both (0.902GHz~0.928GHz and 2.4GHz~2.5GHz) bands. Simulated and measured results indicate that the proposed antenna can achieve good circularly polarized radiation performance.
19
Lin, Chung-Chu, and 林忠助. "Design of Micromachined Wideband Aperture Coupled Microstrip Patch Antenna." Thesis, 2001. http://ndltd.ncl.edu.tw/handle/02144213947617591218.
Повний текст джерелаАнотація:
碩士國立臺北科技大學
機電整合研究所
89
In this thesis, the characteristics of wide band aperture coupled microstrip patch antennas (MPAs) is studied. First, we conduct the basic theoretical analysis of the aperture coupled MPA. We use the full-wave numerical analysis method that has higher accuracy to understand the whole process of analysis. The purpose is to build up foundation of theoretical analysis for wide band aperture coupled MPA. Then, we design a series of the S-band aperture coupled MPA. The cheaper and more available FR4 PCB substrate is used to layout the element of antenna. These antenna structures consist of (a) the traditional aperture coupled MPA, (b) the wide band aperture coupled MPA with a air layer, and (c) the wide band aperture coupled stacked MPA. The simulations and the experimental measurements is used to study the characteristics of these antenna structures, in terms of parameters for the variations of resonant frequencies and input impedance with antenna. The bandwidth of the traditional aperture coupled MPA is measured to be only about 3 %. The bandwidth of the wide band aperture coupled MPA with a air layer is measured to be about 14 %, and maximum antenna gain of 7.7 dBi. The bandwidth of the wide band aperture coupled stacked MPA is measured to be about 33 %, and maximum antenna gain of 7.51 dBi. Next, we design Ka-band wide band aperture coupled MPAs based on the simulation software tool. These antenna structures consist of (a) the wide band aperture coupled MPA with an etched cavity, (b) the wide band aperture coupled stacked MPA. We design these antenna based on micromachined process. Finally, one of the designed Ka-band wide band aperture coupled MPAs has been produced on silicon wafers by using the micromachining technique. The bandwidth (defined as having a return loss of less than —10 dB) of the micromachined wide band aperture coupled MPA is measured to be over 50 %.
20
Chen, Chin-Yi, and 陳晉毅. "DUAL L-SHAPED APERTURE COUPLED WIDEBAND CIRCULARLY POLARIZED ANTENNA." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/90041576368597294826.
Повний текст джерелаАнотація:
碩士大同大學
通訊工程研究所
101
An aperture-coupled patch antenna is presented. The aperture is composed of two L-shaped-like slots and is proximately-fed by an L-shaped-like strip. The L-shaped-like strip is first coupled to the first slot through its vertical arm , then serially coupled to the second slot through its horizontal arm. The length of the vertical and horizontal arms of the L-shaped strip are found highly correlated to the axial- ratio bandwidth of the antenna. The center frequency in the return-loss plot of the antenna is also influenced by the two lengths. The optimized antenna has a return-loss bandwidth of 19.6 % (2.26-2.75 GHz) and an axial-ratio bandwidth of 16 % (2.3-2.7 GHz).
21
Majeed, Asmaa H., Abdulkareem S. Abdullah, Fauzi Elmegri, Khalil H. Sayidmarie, Raed A. Abd-Alhameed, and James M. Noras. "Aperture-Coupled Asymmetric Dielectric Resonators Antenna for Wideband Applications." 2014. http://hdl.handle.net/10454/8422.
Повний текст джерелаАнотація:
yesA compact dielectric resonator antenna (DRA) for wideband applications is proposed. Two cylindrical dielectric resonators which are asymmetrically located with respect to the center of a rectangular coupling aperture are fed through this aperture. By optimizing the design parameters, an impedance bandwidth of about 29%, covering the frequency range from 9.62 GHz to 12.9 GHz, and a gain of 8 dBi are obtained. Design details of the proposed antenna and the results of both simulation and experiment are presented and discussed.
22
Zebiri, Chemseddine, Mohamed Lashab, D. Sayad, Issa T. Elfergani, Khalil H. Sayidmarie, F. Benabdelaziz, Raed A. Abd-Alhameed, Jonathan Rodriguez, and James M. Noras. "Offset Aperture-Coupled Double-Cylinder Dielectric Resonator Antenna with Extended Wideband." 2017. http://hdl.handle.net/10454/13087.
Повний текст джерелаАнотація:
YesA compact dielectric resonator antenna for ultra-wideband vehicular communication applications is proposed. Two cylindrical dielectric resonators are asymmetrically located with respect to the center of an offset rectangular coupling aperture, through which they are fed. Optimizing the design parameters results in an impedance bandwidth of 21%, covering the range from 5.9 to 7.32 GHz in the lower-band and a 53% relative bandwidth from 8.72 to 15 GHz in the upper-band. The maximum achieved gain is 12 dBi. Design details of the proposed antenna and the results of both simulations and experiment are presented and discussed.
23
KUMAR, PEEYUSH. "DESIGN AND ANALYSIS OF APERTURE COUPLED ANTENNA WITH DEFECTIVE GROUND." Thesis, 2017. http://dspace.dtu.ac.in:8080/jspui/handle/repository/16095.
Повний текст джерелаАнотація:
Aperture Coupled Micro-Strip Antenna Design and Analysis A linearly-polarized aperture coupled patch antenna design is characterized and optimized using Agilent ADS antenna simulation software [1]. This thesis focuses on the aperture coupled patch antenna due to the lack of fabrication and tuning documentation for the design of this antenna and its usefulness in arrays and orthogonally polarized communications. The goal of this thesis is to explore dimension effects on aperture coupled antenna performance, to develop a design and tuning procedure, and to describe performance effects through electromagnetic principles. Antenna parameters examined in this study include the dimensions and locations of the substrates, feed line, ground plane coupling slot, and patch. The operating frequency, input VSWR, percent bandwidth, polarization ratio, and broadside gain are determined for each antenna configuration. The substrate material is changed from RT Duroid (material in nominal ADS design [1]) to FR4 due to lower cost and availability. The operating frequency is changed from 2.3GHz (specified in nominal HFSS design) to 2.4GHz for wireless communication applications. Required dimensional adjustments when changing substrate materials and operating frequencies for this antenna are non-trivial and the new design procedure is used to tune the antenna. The antenna is fabricated using 59mil thick double and single sided FR4 boards joined together with double sided 45mil thick acrylic tape. The antenna is characterized in an anechoic chamber and experimental results are compared to theoretical predictions.
24
Song, Yunpeng. "Radiation pattern of aperture coupled prolate hemispheroidal dielectric resonator antenna." Thesis, 2004. http://spectrum.library.concordia.ca/8393/1/MR04400.pdf.
Повний текст джерелаАнотація:
A detailed analysis and study of a prolate hemispheroidal dielectric resonator antenna (DRA) excited by a rectangular slot aperture are developed. The method used is based on the dyadic Green's function technique in the spheroidal coordinates. In this work, the dyadic Green's functions pertaining to a magnetic-current source located in a dielectric spheroid is derived and expressed in a form convenient for numerical computations. The dyadic Green's functions are then employed to formulate the electromagnetic fields radiated by the DRA. The electromagnetic far field is expressed analytically in a compact form. The antenna radiation patterns and directivities are computed for different design parameters. The accuracy of the solution is attested by both comparing with HFSS simulation results and with published data for the corresponding hemispherical dielectric resonator antenna. Furthermore, efficient algorithms for calculating the prolate spheroidal wave functions are developed using the software package MATLAB. The algorithm developed here for calculating the prolate spheroidal function is compact, fast, and efficient, and compared well with other results in the literature.
25
Chen, Wei-Jen, and 陳威任. "Design of A Two-Dimensional Amplifying Antenna Array Using Multi-Ported Aperture-Coupled Patch Antennas." Thesis, 2002. http://ndltd.ncl.edu.tw/handle/43205645809279608852.
Повний текст джерелаАнотація:
碩士國立交通大學
電信工程系
90
This thesis proposes a novel circuit-fed two-dimensional amplifying array using the multi-ported aperture-coupled patch antennas. Power coupling between the patch and feed circuit is through the apertures etched on the ground plane. This array is formed by reproductively connecting three basic cells, each with a multi-ported aperture-coupled patch antenna and some with one or two amplifiers, in sequence like stacking the LEGO blocks, so that a beam-shaped and high-gain amplifying array can be constructed quite quickly. An X-band 4×3 elements array with uniform excitation distribution is demonstrated in this study. The measured return loss of the designed array is below -10 dB in the frequency range from 10 GHz to 10.7 GHz, and shows a resonant frequency of 10.33 GHz. The measured peak gain of the amplifying array comes to 27.7 dBi. The H-plane patterns of the array possess a half-power beamwidth of 14 degrees and a side-lobe level of -11 dB, while the E-plane patterns possess those of 16 degrees and -6 dB, respectively.
26
陳柏州. "Design of Aperture Coupled Tri-polarization Antenna and Dual Planar Inverted-F Tri-polarization Antenna." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/64966525199777868040.
Повний текст джерелаАнотація:
碩士國立交通大學
電信工程研究所
101
A design of aperture coupled tri-polarization antenna is presented in the first part of this thesis. By integrating an aperture coupled-fed antenna and a branch line coupler, the proposed antenna can provide a linear polarization and a pair of orthogonal circular polarizations, realizing the switchable tri-polarization characteristics. Since the phase difference and magnitude from two output ports of the branch line coupler varies by frequency, the polarization characteristic will also be changed. Since the branch line coupler provides two output signals with the same magnitude and 90° phase difference, RHCP and LHCP can therefore be generated by switching two input ports. Also, when the two input ports are fed simultaneously with equal phase, a linear polarization can be obtained. This mechanism can be applied at operation frequency and three times the operation frequency of the branch line coupler. In the second part of this thesis, another structure is presented by using a pair of Planar Inverted-F Antenna (PIFA) to achieve the switchable polarization characteristics. Due to its quarter wavelength resonant characteristic, the equivalent electrical length is reduced, therefore reduces the overall antenna size. In this part, the mechanism of polarization diversity is the same as first part, however, this structure can be operated at the operation frequency and three times the operation frequency of the branch line coupler, and both have switchable tri-polarization characteristics. In the end of the thesis, we introduce the sequential rotation method antenna array, and do some experiments in order to further improve the dual PIFAs' circular polarization bandwidth and beamwidth. The design principles and the polarization mechanisms of proposed antennas will be further discussed in our research of this thesis.
27
Kuan, Hua-Ling, and 關華凌. "Two-Directional Scanning by Using Short Leaky-Wave Antenna Integrated with Aperture Coupled Patch Antenna Phase Array." Thesis, 2001. http://ndltd.ncl.edu.tw/handle/50997717880444311222.
Повний текст джерелаАнотація:
碩士國立交通大學
電信工程系
89
First, we present a two-directional scanning method by using a short leaky-wave antenna (LWA) integrated with aperture coupled patch antenna array on the bottom of the substrate. The aperture coupled patch antenna array is connected to the open end of the leaky-wave antenna. Such design offers another radiation path of the reflected wave and thus suppresses the power of reflected wave. The beam of the patch antenna array on the bottom plane can be steered by tuning individual phase-shifter connected to the patch antenna. The beam of the LWA is dominated by the frequency of input signal. Therefore, the two beams of individual direction can be steered independently. Experimental result shows that the suppression of the reflected wave can be 10 dB at 10.5 GHz with a short LWA length of 6cm (2 wavelengths). The results of return loss reveal that the bandwidth of the short LWA is extended by the proposed structure. Secondly, we propose another two-directional scanning topology that is realized by using a short leaky-wave antenna integrated with aperture coupled LWA on the bottom of the substrate. The topology then can accomplish multi-beam scanning and can also suppress the reflected power. The two-directional scanning of two different radiation patterns on different planes provides more flexibility in beam scanning and has great potential in many applications.
28
Reddy, S. P. "A Reconfigurable Aperture Coupled Microstrip Patch Antenna with Beam Steering Capability on Silicon." Thesis, 2012. http://raiith.iith.ac.in/704/1/EE10M10.pdf.
Повний текст джерелаАнотація:
First reconfigurable antenna came into existence in early 1980s. Reconfigurable
antennas provide various functions in operating frequency, polarization & radiation
patterns since it can be used to avoid noise sources, improve system gain & security
[1]. Reconfiguring the Frequency is the major issue & lot of recent work has been
done on frequency reconfigurability A Barium Strontium Titanate (BST) based
reconfigurable Aperture-coupled patch antenna on high resistivity silicon substrates
with beam steering capability using PIN doides has been proposed in this paper. For
low dielectric constant region in silicon substrate, Micromachined technique is used.
Varying voltage across BST layer changes its permittivity thereby tunable frequency
is achieved and switching p-i-n diodes will steer the beam. A Novel structure is
proposed which gives high directivity (> 6 dB), Good gain (> 5 dB), low VSWR
(<1.5), low control voltages (<80V) & 60° HPBWs & also The proposed
reconfigurable aperture coupled microstrip patch antenna array with beam scanning
capability has almost 40 degree scanning angle and BST based reconfiguring
frequency is achieved with good gain and directivity
29
Majeed, Asmaa H., Abdulkareem S. Abdullah, Fauzi Elmegri, Khalil H. Sayidmarie, Raed A. Abd-Alhameed, and James M. Noras. "Dual Segment S-Shaped Aperture-Coupled Cylindrical Dielectric Resonator Antenna for X-Band Applications." 2015. http://hdl.handle.net/10454/7885.
Повний текст джерелаАнотація:
yesA new low-cost dual-segmented dielectric resonator (DR) antenna design is proposed for wideband applications in the X-band region. Two DRs coupled to an S-shaped slot introduce interesting features. The antenna performance was characterized in terms of the reflection coefficient, gain, and radiation pattern, and detailed simulation studies indicate excellent antenna performance from 7.66 GHz to 11.2 GHz (37.5% fractional bandwidth) with a maximum gain of 6.0 dBi at 10.6 GHz while the fabricated prototype has a matched bandwidth from 7.8 GHz to 11.85 GHz (41% fractional bandwidth) and maximum gain of 6dBi. The antenna is compact, size 1 x 0.83 x 0.327 time the wavelength at 10 GHz. The two DR segments may be located on the same side or on opposite sides of the substrate, giving respectively improved gain or more uniform field patterns. Experimental testing of the prototype performance showed reasonable agreement with the predicted performance.
30
Kim, David G. "Design of Stripline-Fed Dual Polarization Aperture-Coupled Stacked Microstrip Patch Phased Array Antenna for Wideband Application." 2010. http://hdl.handle.net/1969.1/ETD-TAMU-2010-08-8567.
Повний текст джерелаАнотація:
Recent days, antennas play an important role in wireless communication system. Microstrip
patch antennas are well known to have positive features for cost-effective, low profile and
broadband. This type of antenna can be used in wide range of applications such as in wireless
communications, radar systems, and satellites. Inhibiting characteristics of single patch antenna
with low gain and narrow band leads to the research area to have array configuration. Beam
steering antennas are the ideal solution for various systems such as traffic control and collision
avoidance radar systems.
The goal of this work is to design and implement a dual-linear polarization stacked microstrip
patch phased array antenna. Single stacked microstrip patch antenna fed by microstrip line was
designed to have approximately 3 GHz bandwidth in X-band with another ground plane to form
a stripline-fed. Stripline-fed design protects feed lines from any outside effects. The array
configuration was adapted to design in order to accomplish beam scan angle of /- 30 degrees by /- 15 degrees.
Binomial power distribution of 3x2 array structure was used in order to reduce grating lobes, and
changing length of feed lines was implemented for phase shifting. Bowtie cross shape aperture
and dual-offset microstrip feedline was used to feed radiating patches. For the feed network, T-split power divider was implemented and optimized to achieve low loss. The length of microstrip
line was adjusted to meet desired phase shift that in wideband application, the length of the line
had to be long enough to have similar wavelength response over broad frequency range. The
antenna array was designed using standard equations and simulated by electromagnetic analysis
software called Zealand's IE3D which is method-of-moments based simulator. The resulting
measured impedance bandwidth and gain of both microstrip and stripline-fed single antenna are
43 percent and 5 to 10 dBi with low cross polarizations for all frequencies. The array antenna was
measured to have 29 to 60 percent impedance bandwidths depending on the different types of beam
scan angles. The gain of the array antenna is 8 to 13 dBi, and the beams are directed as required
with /- 3 degrees beam scan angle tolerance. The array antenna had a small offset as compared with
simulated results because of the fabrication process such as alignment, distorted feed lines while
etching, and etc, but the bandwidths and array patterns were acceptable.
31
洪天富. "Study of Aperture-coupled Stack Antenna with Minkowski island-based Fractal Patch for Circular Polarization Operation." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/15203252048070565967.
Повний текст джерелаАнотація:
博士逢甲大學
電機與通訊工程博士學位學程
102
The dissertation presents fractal theories, experiments and antenna design for Minkowski-island-based (MIB) fractal patch and complementary Minkowski-island-based (CMIB) fractal patch. Two antennas are discussed in this dissertation. The first antenna is a compact single-feed stack antenna consisting of a MIB fractal patch with perturbation element for circular polarization (CP) application, also proves the MIB fractal which can reduce antenna&;#39;s area. The second antenna is a single-feed stack antenna consisting of a complementary MIB (CMIB) fractal patch with perturbation element for dual-band and dual circular polarization applications, also presents a new transformation which can be expressed in mathematical form for complementary MIB fractal. Three steps for antenna design are as follow: first, to use fractal theories as designing rules such as fractal dimension, fractal iteration, and to use a mathematical form as being expressed MIB and CMIB fractal geometries. Second, by using commercial software of ANSYS HFSS to analysis antenna&;#39;s features such as AR spectrum, current distribution, radiation patterns, and reflection coefficient. Finally, experiment, verify and discuss by an investigation on those antenna&;#39;s features. The antenna configuration is makeed with double-layer FR4 glass-fiber board. The lower layer is fed by a 50Ω microstrip line with aperture-coupled to the upper fractal patch. The upper layer is fractal patch, and using perturbation element to excite orthogonal mode for CP operation.
32
Chen, Rui-Hung, and 陳叡宏. "Aperture-coupled Microstrip Antennas." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/16893397530408364206.
Повний текст джерелаАнотація:
碩士國立彰化師範大學
電機工程學系
95
This thesis presents the designs of an aperture-coupled microstrip antenna with switchable polarization. Two orthogonal modes of the microstrip antenna can be excited by a series microstrip-line-feed configuration through the coupling of a ring slot in the ground plane. For the ring-slot-coupled microstrip antenna, the antenna can radiate linear (LP) or circular polarization (CP) with good performances by selecting a proper length of the open stub in the feed line. In addition, the LP radiation also can be excited through the coupling of an open-ring slot instead of the ring slot. The effects of the key parameters of the proposed design on the CP and LP performances are first investigated in details. Then, by using pin diodes to reconfigure the coupling slot and the stub length, the polarizations of the microstrip antenna can be electrically switched. Different polarization switching designs have been achieved, including linear / circular polarization, dual linear polarizations, and dual circular polarizations. Finally, the aperture-coupled microstrip antenna with quad polarization switching is also designed and implemented. From the obtained results, each polarization is operated at the same frequency band and has a broadside radiation pattern with low cross polarization.
33
Chang, Sung-Hsien, and 張嵩賢. "Wide-Band Aperture-Coupled Microstrip Antennas." Thesis, 1994. http://ndltd.ncl.edu.tw/handle/55325333498767240667.
Повний текст джерелаАнотація:
碩士國立交通大學
電信研究所
82
This thesis presents two approaches to increase the antenna's bandwidth of conventional aperture coupled microstrip antenna structure. One is coplanar patches with one aperture coupled to microstrip line, the other is series-fed patches with apertures coupled to microstrip line. Both configurations are analyzed using an integral equation technique solved in spectral domain with the Galerkin method of moments. New numerically efficient methods are applied to expediate the calculations. Experimental data are shown to be in be good agreement with the calculated results. The effect of varying geometric parameters of the structure is discussed with a goal of designing wide-band microstrip antenna.
34
Herscovici, Naftali I. "Analysis of aperture coupled microstrip transmission lines and antennas." 1992. https://scholarworks.umass.edu/dissertations/AAI9305839.
Повний текст джерелаАнотація:
The main subject of this work is the modular design of multilayer printed arrays. The need for a multilayer feeding network is evident in large arrays with a large number of power dividers or phase shifters. Due to space considerations the spurious coupling between the network and the radiating elements, or between different parts of the network itself, can be significant enough to degrade performance. In addition, corporate feed network radiation can affect the sidelobe and cross-polarization characteristics of the array. The use of a multilayer feed network located in a different plane than the radiating elements can alleviate these problems. The transfer of power between two adjacent layers in a multilayer structure can be done using either a pin which makes an electrical contact, or via coupling apertures in the ground plane separating the layers. Beyond the advantages of fabrication, aperture coupling leads to inherently symmetric feed network layouts which further simplify the design. The Green's functions for multilayer dielectric substrates can be used to compute the characteristic impedance of any printed planar transmission line and the full-wave analysis of an entire multilayer network can be obtained. In the past, full-wave solutions were derived for different configurations involving the coupling from one layer to another by means of a rectangular slot. The number of possible configurations is quite limited, since in a typical planar multi layer structure there may be only two microstrip layers (the outermost layers), while the inner layers are typically stripline. This leaves two types of aperture coupling transitions: microstrip to stripline and stripline to stripline. Assuming that the coupling between separate apertures and the coupling between patches is negligible, having a model for each of these two transitions is enough to analyze and design the whole multilayer structure. The radiating elements can also be fed by aperture coupling, and a separate analysis has to be performed for each configuration. Furthermore, the radiating element layer can be placed in a plane perpendicular to the feeding network. The theory used in the modeling of different transitions will be presented first. The reciprocity technique first developed in (9) and further extended in (10) proves to be computationally efficient and gives good results for these cases. The models for individual transitions are validated by measurements and subsequently used in the design of a number of prototype multilayer planar arrays.
35
Chabi, Mhamed. "Modelling and analysis of aperture coupled cylindrical dielectric resonator antennas." 1995. http://hdl.handle.net/1993/18791.
Повний текст джерела
36
Chang, Wei-Chun. "Investigation of waveguide-fed, slot and aperture-coupled-patch antennas." 2001. https://scholarworks.umass.edu/dissertations/AAI3012121.
Повний текст джерелаАнотація:
Waveguide-fed, slot and aperture-coupled patch arrays suitable for a radiometer operating at K-band have been studied. Using such antennas, an electrical scanned thinned array radiometer (ESTAR) operating at 18.7 GHz can be built with dual linear-polarization and conical-scan capability. Green's functions involving spatial and spectral domain variables have been derived and used to obtain the current on the patches and the coupling apertures. Computer simulation code using triangular basis functions are developed to analyze slot-patch radiating elements. The simulation is verified with empirical data and published data. Prototype arrays were built and measured. Design curves based on the simulations are also derived.
37
Chang, Chun-Chuan, and 張鈞全. "A Design of Aperture-Coupled Microstrip Antennas with Low Cross-Polarization." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/39298894366760812886.
Повний текст джерелаАнотація:
碩士國立彰化師範大學
電機工程學系
96
The thesis first presents the performances of microstrip patch antennas excited by the aperture-coupling feed that is composed of a T-shaped microstrip feed line and an annular-ring slot. Because the annular-ring slot is designed at a full-wavelength resonant mode, a broad impedance bandwidth can be obtained by combing the resonant modes of the coupling slot and radiating patch; moreover, a low cross polarization is also observed, especially around the direction with maximum gain. Several prototypes of the proposed aperture-coupled microstrip antennas with different substrate thickness are constructed and measured, and their performances are demonstrated. For reducing the considerable back radiation induced by the resonant coupling slot, additional slots are introduced and embedded along the perimeter of the annular-ring slot, and a 5 dB improvement of front-to-back ratio is obtained. Then, a design of dual-feed dual-polarized microstrip antennas with low cross polarization and high isolation is proposed. The proposed design uses two different feed mechanisms to respectively excite dual orthogonal linearly-polarized modes of a single radiating patch. One of the two modes is excited by the ring-slot-coupled feed, and the other is excited by a pair of meandering strips with a 180° phase difference. The measured results show that the isolation between the two feeding ports is less than -40 dB across a 10dB-input-impedance bandwidth of 14 %. Details of the antenna designs and measured results are shown.
38
Lin, Dah-Yah, and 林大業. "The design of dual-polarization aperture coupled microstrip antennas and the mircowave switch." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/57907036162996911636.
Повний текст джерелаАнотація:
碩士國立中央大學
通訊工程研究所
93
In the thesis, two types of designs of dual-polarized aperture-coupled microstrip antennas are proposed. In the first design, the bandwidth (for VSWR<2) is increased to at least 2 times of single patch antenna, while the isolation between two ports for different polarization remain the same. In the second design, the performance of both bandwidth and isolation are improved. The thesis also discusses the design theorem and set up the design flow graph of antenna. Finally a single-pole single-throw (SPST) switch is developed for dual-polarized system.
39
Lin, Jyun-ming, and 林俊鳴. "NEW FEED STRUCTURES FOR THE BROADBAND AND DUAL BAND APERTURE-COUPLED CIRCULARLY POLARIZED ANTENNAS." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/59357370002358608505.
Повний текст джерелаАнотація:
博士大同大學
通訊工程研究所
100
Three circularly polarized antennas are designed in this dissertation. The first one is operated on a wide bandwidth (2.42 GHz–2.64 GHz); the second and the third one are dual-band (centred at 0.9 GHz and 2.45 GHz) antennas. For the wideband antenna, a novel aperture-coupled ring-antenna is presented. The antenna is fed by a microstrip line through a unique aperture coupling configuration. The aperture contains a square slot ring with four short branch slots protruding toward the center of the ring. It is studied that the axial-ratio bandwidth of 8.7% centered at 2.42 GHz–2.64GHz can be achieved. For the dual-band antenna, we use a nested ring and patch where the patch is placed inside the ring. The patch is operated on the higher-band part; the ring is operated on the lower-band part of the dual-band antenna. This dual-band antenna is excited by two different feeding structures. The first one combines two aperture-coupled structures in serial; and the second one combines two aperture-coupled structures in parallel. The main contribution of the dissertation is to present the above new aperture-coupled methods to excite the ring or/and the patch. In the past, the aperture-coupled method is only used to excite an antenna for single-band operation. In this dissertation, we successfully extend the method to excite two antennas. To save space, the two antennas are arranged to have one patch antenna placed inside one ring antenna. With this configuration, it is easy to implement the dual-band operation by our proposed serial or parallel feeding method. Another contribution of this dissertation is to present a new aperture-coupled feeding structure applied to a single-wide band (ring) antenna. In the past, the aperture coupled method is often used to excite the patch antenna. Our study reveals that the aperture coupled method is also applicable to excite a ring with a slight modification.