Дисертації з теми "Ultrawideband antennas"
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1
Moulder, William F. "Novel Implementations of Ultrawideband Tightly Coupled Antenna Arrays." The Ohio State University, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=osu1354024399.
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2
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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Almalkawi, Mohammad J. "Computer Aided Design of Microwave Front-End Components and Antennas for Ultrawideband Systems." University of Toledo / OhioLINK, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1321653715.
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4
Irci, Erdinc. "Low-Profile Wideband Antennas Based on Tightly Coupled Dipole and Patch Elements." The Ohio State University, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=osu1316456337.
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5
Cheng, Shi. "Integrated Antenna Solutions for Wireless Sensor and Millimeter-Wave Systems." Doctoral thesis, Uppsala universitet, Mikrovågs- och terahertzteknik, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-111197.
Повний текст джерелаАнотація:
This thesis presents various integrated antenna solutions for different types of systems and applications, e.g. wireless sensors, broadband handsets, advanced base stations, MEMS-based reconfigurable front-ends, automotive anti-collision radars, and large area electronics. For wireless sensor applications, a T-matched dipole is proposed and integrated in an electrically small body-worn sensor node. Measurement techniques are developed to characterize the port impedance and radiation properties. Possibilities and limitations of the planar inverted cone antenna (PICA) for small handsets are studied experimentally. Printed slot-type and folded PICAs are demonstrated for UWB handheld terminals. Both monolithic and hybrid integration are applied for electrically steerable array antennas. Compact phase shifters within a traveling wave array antenna architecture, on single layer substrate, is investigated for the first time. Radio frequency MEMS switches are utilized to improve the performance of reconfigurable antennas at higher frequencies. Using monolithic integration, a 20 GHz switched beam antenna based on MEMS switches is implemented and evaluated. Compared to similar work published previously, complete experimental results are here for the first time reported. Moreover, a hybrid approach is used for a 24 GHz switched beam traveling wave array antenna. A MEMS router is fabricated on silicon substrate for switching two array antennas on a LTCC chip. A concept of nano-wire based substrate integrated waveguides (SIW) is proposed for millimeter-wave applications. Antenna prototypes based on this concept are successfully demonstrated for automotive radar applications. W-band body-worn nonlinear harmonic radar reflectors are proposed as a means to improve automotive radar functionality. Passive, semi-passive and active nonlinear reflectors consisting of array antennas and nonlinear circuitry on flex foils are investigated. A new stretchable RF electronics concept for large area electronics is demonstrated. It incorporates liquid metal into microstructured elastic channels. The prototypes exhibit high stretchability, foldability, and twistability, with maintained electrical properties.wisenet
6
Ghonein, El Hage. "FDTD antenna modeling for ultrawideband electromagnetic remote sensing." Connect to this title online, 2005. http://hdl.handle.net/1811/315.
Повний текст джерелаАнотація:
Thesis (Honors)--Ohio State University, 2005.Title from first page of PDF file. Document formattted into pages: contains 25 p.; also includes graphics. Includes bibliographical references. Available online via Ohio State University's Knowledge Bank.
7
Tzanidis, Ioannis. "Ultrawideband Low-Profile Arrays of Tightly Coupled Antenna Elements: Excitation, Termination and Feeding Methods." The Ohio State University, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=osu1316439948.
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8
Lopez-Castellanos, Victor. "Ultrawideband Time Domain Radar for Time Reversal Applications." The Ohio State University, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=osu1301040987.
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9
Vo, Henry Hoang. "DEVELOPMENT OF AN ULTRA-WIDEBAND LOW-PROFILE WIDE SCAN ANGLE PHASED ARRAY ANTENNA." The Ohio State University, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=osu1437692437.
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10
Yu, Xiaoju, Rongguo Zhou, Hualiang Zhang, and Hao Xin. "A Microwave Direction of Arrival Estimation Technique Using a Single Antenna." IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, 2016. http://hdl.handle.net/10150/621549.
Повний текст джерелаАнотація:
A direction of arrival (DoA) estimation technique for broadband microwave signals is proposed using a single ultrawideband antenna. It is inspired by the sound source localization ability of a human auditory system using just one ear (monaural localization). By exploiting the incident angle-dependent frequency response of a wideband antenna, the DoA of a broadband microwave signal can be estimated. The DoA estimation accuracies are evaluated for two antenna configurations and microwave signals with different signal-to-noise ratios. Encouraging the DoA estimation performance of the proposed technique is demonstrated in both simulation and experiment.
11
Ethier, Jonathan L. T. "Antenna Shape Synthesis Using Characteristic Mode Concepts." Thèse, Université d'Ottawa / University of Ottawa, 2012. http://hdl.handle.net/10393/23464.
Повний текст джерелаАнотація:
Characteristic modes (CMs) provide deep insight into the electromagnetic behaviour of any arbitrarily shaped conducting structure because the CMs are unique to the geometry of the object. We exploit this very fact by predicting a perhaps surprising number of important antenna metrics such as resonance frequency, radiation efficiency and antenna Q (bandwidth) without needing to specify a feeding location. In doing so, it is possible to define a collection of objective functions that can be used in an optimizer to shape-synthesize antennas without needing to define a feed location a priori. We denote this novel form of optimization “feedless” or “excitation-free” antenna shape synthesis. Fundamentally, we are allowing the electromagnetics to dictate how the antenna synthesis should proceed and are in no way imposing the physical constraints enforced by fixed feeding structures. This optimization technique is broadly applied to three major areas of antenna research: electrically small antennas, multi-band antennas and reflectarrays. Thus, the scope of applicability ranges from small antennas, to intermediate sizes and concludes with electrically large antenna designs, which is a testament to the broad applicability of characteristic mode theory. Another advantage of feedless electromagnetic shape synthesis is the ability to synthesize antennas whose desirable properties approach the fundamental limits imposed by electromagnetics. As an additional benefit, the feedless optimization technique is shown to have greater computational efficiency than traditional antenna optimization techniques.
12
N?brega, Clarissa de Lucena. "Otimiza??o dos par?metros de monopolos planares de microfita para aplica??es em sistemas de banda ultra larga." Universidade Federal do Rio Grande do Norte, 2008. http://repositorio.ufrn.br:8080/jspui/handle/123456789/15200.
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This work presents a theoretical and experimental investigation about the properties of microstrip antennas for ultra-wideband systems. Configurations of elliptic monopoles with different eccentricities and circular monopoles are considered. Two prototypes for each antenna configuration were built, one with the typical microstrip configuration and the other is similar to the first, except for a small aperture in the ground plane. Therefore, this work proposes to modify the configuration of the ground plane of the monopoles designed adding a rectangular stub, in order to optimize and improve the performance of such structures. The obtained results show that the introduction of that rectangular aperture in the ground plane allows an improvement of the frequency response for the considered antenna propotypes. It is observed a good agreement between the measured and simulated results. Finally, some proposals for future works are presented
Este trabalho apresenta uma investiga??o te?rica e experimental sobre as propriedades de antenas de microfita para sistemas de banda ultra larga. S?o consideradas configura??es de monopolos el?pticos com excentricidades diferentes, e monopolos circulares. Foram constru?dos dois prot?tipos para cada configura??o de antena, um com a configura??o t?pica de microfita e outro similar ao primeiro, mas com uma pequena abertura no plano de terra. Assim, este trabalho objetiva modificar a configura??o do plano de terra dos monopolos projetados atrav?s da inser??o de um recorte retangular, para fins de otimiza??o e melhoria nos desempenhos das estruturas. Os resultados obtidos mostram que a introdu??o dessa abertura retangular no plano de terra permite melhorar a resposta em freq??ncia das antenas consideradas. Observa-se uma boa concord?ncia entre os resultados medidos e simulados. Algumas propostas para a realiza??o de trabalhos futuros s?o apresentadas
13
Lin, Jiun-Da, and 林君達. "Design of Ultrawideband Dielectric Resonator Antennas." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/quv6sc.
Повний текст джерелаАнотація:
碩士國立臺北科技大學
電腦與通訊研究所
102
In this thesis, The new dielectric resonator antenna(DRA) is implemented by replacing the traditional dielectric resonator with a new material with low permittivity for ultrawideband (UWB) application is presented and studied. First, a hybrid structure DRA was designed with parasitic slot to enhance the impedance bandwidth. The flexible design consist of a coplanar waveguide (CPW) feed and parasitic slot. The bandwidth met the specification of MB-OFDM for the bandwidth(3.168-4.752GHz). Finally, another antenna structure was designed by changing the size of the dielectric resonator to satisfy the boundary conditions of the lower band. By applying the microstrip feed line, UWB and radiation characteristics are achieved. From the measured results, the proposed DRA showed good radiation pattern, high gain (5.2dBi), wide bandwidth (3.03-11GHz) and compact size ( ). The bandwidth met the specification of MB-OFDM (3.168-10.56GHz).The antenna system proposed in this work showed potential for mass production due to the simplicity of the design.
14
Malakooti, Seyedali. "Ultrawideband and Multi-state Reconfigurable Antennas with Sum and Difference Radiation Patterns." Thesis, 2019. http://hdl.handle.net/2440/124259.
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Pattern diversity is a term used to describe the operation of several antenna elements working together to produce multiple different radiation patterns with the aim of improving the quality and reliability of a communications system. One useful implementation of pattern diversity considers sum and difference radiation patterns which can be exploited to extend high-gain space coverage and tackle multipath fading. The conventional forms of such pattern diversity antennas are generally working at a single or multiple narrowband frequencies and are designed for specific applications. Hence, generating sum and difference pattern diversity in wide range of frequencies requires the development of new pattern diversity antenna designs. Ultrawideband and frequency reconfigurable designs of pattern diversity antennas are desirable to help reduce the cost and increase the flexibility in applications of pattern diversity antennas. These two types of performances constitute the principal parts of this thesis. The first part of this thesis deals with the challenges of designing ultrawideband Vivaldi antennas with sum and difference radiation patterns. When two Vivaldi antennas are placed next to each other, two mutually exclusive phenomena of grating lobe generation at the highest end of frequency and mutual coupling at the lowest end of frequency will define the bandwidth. Hence, to enhance the bandwidth, the separation between the antenna elements is reduced, which delays the grating lobes generation, and the coupling at lower frequencies is mitigated by introducing an asymmetry in the design of each Vivaldi antenna element. It is shown that this method can be extended to multi-element Vivaldi antennas for higher gain. Next, the bandwidth is further enhanced by adding two vertical metal slabs between the antenna elements improving the isolation at lower frequencies. The proposed antennas use commercially available couplers as feeding networks. As a potential replacement for couplers, an out-of-phase power divider with unequal power division is also proposed. In the second part of this thesis, the pattern diversity function is combined with multistate frequency-reconfigurable filtering functions in a series of novel designs. In the first proposed design, two quasi-Yagi-Uda antennas are used for pattern diversity, while two switchable and reconfigurable bandpass-to-bandstop filters are used to excite the antenna elements. The whole system is excited by an external commercially available rat-race coupler. In a next step, this design is modified to attain wideband, tunable bandpass, and tunable bandstop operations while obviating the need for an external coupler by using three antenna elements excited by a switchable power divider. In another implementation, the filtering functions is extended to dual-band independently tunable bandpass and bandstop to excite wideband antennas. While all the former designs featured E-plane pattern diversity, in another design aiming at increasing space coverage, a switchable patch antennas with sum and difference radiation patterns in both E- and H-plane of the antenna is designed.Thesis (Ph.D.) -- University of Adelaide, School of Electrical and Electronic Engineering, 2020
15
Chang, Wan-lin, and 張琬琳. "Design and Analysis of Multiband and Ultrawideband Planar Monopole Antennas." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/25971630227546556089.
Повний текст джерелаАнотація:
碩士國立臺灣科技大學
電機工程系
96
This thesis investigates two new antenna designs. The first antenna is a four-arm planar monopole for mobile phone applications. The antenna covers the frequency bands including GSM900, DCS1800, PCS1900, IMT2000, and WLAN 802.11 a/b/g.The second antenna design is a multilayered ultrawideband antenna with band-notched characteristics. The antenna is designed for ultrawideband applications from 3.1 to 10.6 GHz with a rejection band at 5 to 6 GHz. The notched band is capable of alleviating the interference from the WLAN signals.
16
Yang, Chih-Hsiang, and 楊智翔. "Planar Band-Notched Ultrawideband Monopole Antennas for Wireless USB Dongle Applications." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/33973316989985579344.
Повний текст джерелаАнотація:
碩士國立宜蘭大學
電子工程學系碩士班
97
The goal of this thesis is to design a planar monopole UWB antenna with a small size, a simple structure and a band-rejection feature for wireless USB dongle applications. To meet the specification of usage frequency band allocated from 3.1GHz to 10.6GHz, an empirical formula for antenna design is first employed to design a rectangular planar monopole UWB antenna. Then, a staircase with three steps near the feeding port was modified and tuned to improve impedance bandwidth. The measured results exhibit its ultra-wide bandwidth and omni-directional patterns and it demonstrates the planar monopole antenna is suitable for UWB wireless dongle receiver. To avoid interference with existing wireless local area networks (WLANs) systems between 5 and 6 GHz, UWB antennas with band–rejection characteristics were presented. Here, three kinds of band–notched approaches were proposed and designed : first is quarter–wavelength parasitic stripline resonator printed on the back plane of the PCB, second is a half–wavelength U–shaped parasitic stripline resonator on the back plane of the PCB, and third is a complementary split–ring resonator (CSRR) embedded on the monopole conductor. The experiment confirms the band–rejection capability but the monopole antenna is still preserving the UWB features. The printed UWB antenna is comprised of a planar monopole radiator and the ground plane which are connected to a coaxial cable to launch RF signals. This kind of ground and antenna system is essentially an unbalanced design, where electric currents are distributed on both radiator and ground plane, and then leakage to the outer conductor of the feeding cable. The impedance matching and radiation pattern will be influenced in the low band, which are our focus. Finally, some techniques will be proposed to reduce the cable effect on the antenna performance.
17
Wu, Jheng-Yuan, and 吳政遠. "The Compact Designs of Monopole Printed Antennas Array for UltraWideband Applications." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/51076979320226628965.
Повний текст джерелаАнотація:
碩士北台灣科學技術學院
機電整合研究所
98
This thesis proposes a novel ultra-wideband array antenna and excited by a printed patch monopole. The designs of 1×2 and 2×2 array antennas were fabricated on a low-cost FR4 substrate by 2 and 4 elements of microstrip patches. The T-junctions and quarter-wavelength impedance transformers were used to realized an ultra-wideband array antenna. The -10 dB return loss bandwidth of single element could be reached about 111.42% with respect to the center frequency at 7GHz. The bandwidths of 1×2 and 2×2 array antennas were 122.3% and 122.8% respectively. The maximum antenna gain of the single element is 4.6dB. Both 1×2 and 2×2 array antennas show obviously increase in maximum antenna gain.
18
See, Chan H., Hmeda I. Hraga, Raed A. Abd-Alhameed, Neil J. McEwan, James M. Noras, and Peter S. Excell. "A Low-Profile Ultra-Wideband Modified Planar Inverted-F Antenna." 2013. http://hdl.handle.net/10454/9727.
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NoA miniaturized modified planar inverted-F antenna (PIFA) is presented and experimentally studied. This antenna consists of a planar rectangular monopole top-loaded with a rectangular patch attached to two rectangular plates, one shorted to the ground and the other suspended, both placed at the optimum distance on each side of the planar monopole. The fabricated antenna prototype had a measured impedance bandwidth of 125%, covering 3 to 13GHz for reflection coefficient better than -10 dB. The radiator size was 20 x 10 x 7.5 mm(3), making it electrically small over most of the band and suitable for incorporation in mobile devices. The radiation patterns and gains of this antenna have been cross-validated numerically and experimentally and confirm that this antenna has adequate characteristics for short range ultra-wideband wireless applications.
19
Zhu, F., S. Gao, A. T. S. Ho, Raed A. Abd-Alhameed, Chan H. See, T. W. C. Brown, J. Li, G. Wei, and J. Xu. "Multiple Band-Notched UWB Antenna With Band-Rejected Elements Integrated in the Feed Line." 2013. http://hdl.handle.net/10454/9770.
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NoTo mitigate potential interferences with coexisting wireless systems operating over 3.3-3.6 GHz, 5.15-5.35 GHz, or 5.725-5.825 GHz bands, four novel band-notched antennas suitable for ultra-wideband (UWB) applications are proposed. These include UWB antennas with a single wide notched band, a single narrow notched band, dual notched bands, and triple notched bands. Each antenna comprises a half-circle shaped patch with an open rectangular slot and a half-circle shaped ground plane. Good band-notched performance is achieved by using high permittivity and low dielectric loss substrate, and inserting quarter-wavelength horizontal/vertical stubs or alternatively embedding quarter-wavelength open-ended slots within the feed line. The results of both simulation and measurement confirm that the gain suppression of the single and multiple band-notched antennas in each desired notched band are over 15 dB and 10 dB, respectively. The radiation pattern of the proposed triple band-notched design is relatively stable across the operating frequency band.
20
HUANG, DA-CHENG, and 黃大誠. "Ultrawideband Antenna Design for Bluetooth,LTE,WLAN and X Band." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/s2q586.
Повний текст джерелаАнотація:
碩士大葉大學
電機工程學系
106
This paper presents Ultra-Wideband antenna for Bluetooth , LTE , WLAN and X Band.The proposed Ultra-Wideband antenna system operates 2.3-2.96 GHz(TDD-LTE/Bluetooth) and 4.2-10.6 GHz(WLAN and X Band). In the 3.3 to 3.6 GHz (World interoperability for microwave access) and 3.6 to 4.2 GHz (C-band satellite applications) .These both bands cause interference with UWB devices. The antenna is designed using 1.6 mm FR-4 dielectric substrate having a dielectric constant of 4.4 and loss tangent of 0.02. The reflectance of the operational frequency band is below -10 dB.
21
Hraga, Hmeda I., Chan H. See, Raed A. Abd-Alhameed, Steven M. R. Jones, Mark B. Child, Issa T. Elfergani, and Peter S. Excell. "Design of a Planar Inverted F-L Antenna (PIFLA) for Lower-band UWB Applications." 2010. http://hdl.handle.net/10454/4786.
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YesThis paper examines the case for an ultrawideband planar inverted-F-L-antenna design intended for use in the lower sub-band. The antenna construction is based on the conventional inverted F, and inverted L as its feed element, and parasitic element, respectively. The optimized antenna size is 30×15×4mm3. The prototype antenna has a good return loss of -10 dB, and a 66.6% impedance bandwidth (2.8 GHz ¿ 5.6 GHz), the gain varies between 3.1 dBi and 4.5 dBi.
22
Logan, John. "A New Class of Improved Bandwidth Planar Ultrawideband Modular Antenna (puma) Arrays Scalable to mm-Waves." 2013. https://scholarworks.umass.edu/theses/1060.
Повний текст джерелаАнотація:
A new class of Planar Ultrawideband Modular Antenna (PUMA) arrays, termed PUMAv3, is introduced to offer improved performance and further meet demand needs for multifunctional systems. PUMAv3 extends the frequency scalability of PUMA arrays to mm-waves (approximately 50 GHz) and improves bandwidth by 50\% without the use of a matching network or external baluns. The major enabling technical innovation is the advent of a new common-mode mitigation mechanism that relies upon capacitively-loaded shorting vias to push broadside catastrophic resonances below the operating band without inhibiting low-end bandwidth performance. Ridged waveguide models are employed to explain the operational principles and accurately predict the location of the common-mode frequency within the new array topology. Additionally, the superstrate loading scheme is split into two exclusive layers to enhance broadside and wide angle impedance levels while maintaining the highest frequency at 97% of the grating lobe frequency and reducing the overall array profile by up to 30%. The PUMAv3 also retains the attractive practical advantages inherent to the PUMA array family: aperture modularity, direct 50-ohm feeding, and low-cost planar multilayer PCB fabrication. Infinite array full-wave simulations of a dual-polarized PUMAv3 satisfying manufacture guidelines suggest 10.6-47.6 GHz (4.5:1) operation with strong VSWR levels out to 45 degrees, high port isolation and low cross-polarization.
23
Holland, Steven S. "Low-profile, modular, ultra-wideband phased arrays." 2011. https://scholarworks.umass.edu/dissertations/AAI3482706.
Повний текст джерелаАнотація:
Ultrawideband (UWB) phased antenna arrays are critical to the success of future multi-functional communication, sensing, and countermeasure systems, which will utilize a few UWB phased arrays in place of multiple antennas on a platform. The success of this new systems approach relies in part on the ability to manufacture and assemble low-cost UWB phased arrays with excellent radiation characteristics. This dissertation presents the theory and design of a new class of UWB arrays that is based on unbalanced fed tightly-coupled horizontal dipoles over a ground plane. Practical implementation of this concept leads to two inexpensive wideband array topologies, the Banyan Tree Antenna (BTA) Array, and the Planar Ultrawideband Modular Antenna (PUMA) Array. The key challenge in designing unbalanced-fed tightly-coupled dipole arrays lies in the control of a common mode resonance that destroys UWB performance. This work introduces a novel feeding strategy that eliminates this resonance and results in wideband, wide-angle radiation. More importantly, the new feeding scheme is simple and intuitive, and can be implemented at low-cost in both vertically- and planarly-integrated phased array architectures. Another desirable byproduct of this topology is the electrical and mechanical modularity of the aperture, which enables easy manufacturability and assembly. A theoretical framework is presented for the new phased array topologies, which is then applied to the design of infinite BTA and PUMA arrays that achieve 4:1 and 5:1 bandwidths, respectively. A practical application of this technology is demonstrated through the full design, fabrication, and measurement of a 7.25–21GHz 16x16 dual-polarized PUMA array prototype for SATCOM applications.
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Василенко, Дмитро Олексійович. "Конструктивний синтез планарних антен природними алгоритмами оптимізації". Doctoral thesis, 2010. https://ela.kpi.ua/handle/123456789/641.
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