121 research outputs found

    Interleavers

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    The chapter describes principles, analysis, design, properties, and implementations of optical frequency (or wavelength) interleavers. The emphasis is on finite impulse response devices based on cascaded Mach-Zehnder-type filter elements with carefully designed coupling ratios, the so-called resonant couplers. Another important class that is discussed is the infinite impulse response type, based on e.g. Fabry-Perot, Gires-Tournois, or ring resonators

    Analogue filter networks: developments in theory, design and analyses

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    UWB Technology

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    Ultra Wide Band (UWB) technology has attracted increasing interest and there is a growing demand for UWB for several applications and scenarios. The unlicensed use of the UWB spectrum has been regulated by the Federal Communications Commission (FCC) since the early 2000s. The main concern in designing UWB circuits is to consider the assigned bandwidth and the low power permitted for transmission. This makes UWB circuit design a challenging mission in today's community. Various circuit designs and system implementations are published in this book to give the reader a glimpse of the state-of-the-art examples in this field. The book starts at the circuit level design of major UWB elements such as filters, antennas, and amplifiers; and ends with the complete system implementation using such modules

    Multifrequency Aperture-Synthesizing Microwave Radiometer System (MFASMR). Volume 1

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    Background material and a systems analysis of a multifrequency aperture - synthesizing microwave radiometer system is presented. It was found that the system does not exhibit high performance because much of the available thermal power is not used in the construction of the image and because the image that can be formed has a resolution of only ten lines. An analysis of image reconstruction is given. The system is compared with conventional aperture synthesis systems

    The applications of near infra-red fibre bragg grating sensors for wave propagation based structural health monitoring of thin laminated composite plates

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    This thesis contributes to the research and development towards achieving better structural health monitoring (SHM) system for composite structures. Composites are widely used in critical engineering applications due to the advantage of higher specific strength and stiffness compared to other conventional materials. However, composite laminates have a very high probability of unexpected damage development during service. This study uses fiber Bragg grating (FBG) sensor to create a practical and robust SHM tool based on monitoring the acoustic emission, in order to provide continuous information of the structure's condition. The remarkable capability of using the FBG sensors for dynamic sensing has been demonstrated, in particular for the wave propagation based SHM. Combined with FBG sensor technologies, the wave propagation based SHM such as acoustic emission (AE), ultrasonic evaluation and acousto-ultrasonics becomes more exciting. The FBG sensor has the ability of acquiring both static and dynamic strains with a single sensor. Besides, the physical size of FBG sensor provides greater access to embed them in composite structures without significantly affecting its structural properties. This study also emphasizes some drawbacks in the use of piezoelectric sensors in the wave propagation based SHM of composite structures, specifically in the AE applications. In most optical fiber based SHM applications to date, people have used only FBG sensors with wavelength 1550 nm. The FBG sensors with this wavelength are commonly used in industries such as telecommunications and health. However, there is an option of using near infra-red (NIR) FBG range which is comparably cheap in terms of total system design, yet offers the same performance of a conventional 1550 nm range FBGs. This research work presents the NIR FBG dynamic sensing system, as a wave propagation-based SHM system for monitoring the damages in thin glass fiber reinforced composite plates. The NIR-FBG sensor system has been validated successfully, in particular for thin composite plate's applications. The sensor system has shown its unique capability whereby it can be applied in the area which cannot be accessed by standard piezoelectric based system. The developed NIR FBG sensor system has shown its competitiveness and ability to replace the piezoelectric sensors in the 'wave propagation based SHM' of laminated composite plates

    Fiber Optic Sensors and Fiber Lasers

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    The optical fiber industry is emerging from the market for selling simple accessories using optical fiber to the new optical-IT convergence sensor market combined with high value-added smart industries such as the bio industry. Among them, fiber optic sensors and fiber lasers are growing faster and more accurately by utilizing fiber optics in various fields such as shipbuilding, construction, energy, military, railway, security, and medical.This Special Issue aims to present novel and innovative applications of sensors and devices based on fiber optic sensors and fiber lasers, and covers a wide range of applications of optical sensors. In this Special Issue, original research articles, as well as reviews, have been published

    Band-pass waveguide filters and multiplexers design by the structure segmentation technique

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    This work presents a technique for the efficient design of bandpass waveguide microwave filters using a segmentation technique. The segmentation technique was originally developed for in-line filters, and the main contribution of this work is in the combination of this technique with the coupling matrix formalism. In this way we have used this useful design technique for complex coupling topologies, beyond the in-line configuration. As an example some dual mode filters are designed using the new coupling matrix formalism, validating the theory presented. In addition, this technique has been used in the design of diplexers and triplexers with the previously designed filters. Furthermore, a novel dual-mode filter topology that can be implemented through this technique is proposed. Finally, in order to validate these contributions, a dual-mode filter has been designed with the introduced topology for a real application in the space sector in collaboration with the European Space Agency.Universidad Politécnica de Cartagen

    2008 Index IEEE Transactions on Control Systems Technology Vol. 16

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    This index covers all technical items - papers, correspondence, reviews, etc. - that appeared in this periodical during the year, and items from previous years that were commented upon or corrected in this year. Departments and other items may also be covered if they have been judged to have archival value. The Author Index contains the primary entry for each item, listed under the first author\u27s name. The primary entry includes the coauthors\u27 names, the title of the paper or other item, and its location, specified by the publication abbreviation, year, month, and inclusive pagination. The Subject Index contains entries describing the item under all appropriate subject headings, plus the first author\u27s name, the publication abbreviation, month, and year, and inclusive pages. Note that the item title is found only under the primary entry in the Author Index
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