Spelling suggestions: "subject:"(dde)multiplexed"" "subject:"(dee)multiplexed""
31 |
Circuits photoniques intégrés III-V/Si pour les applications en télécommunications optiques / Hybrid III-V/Si photonic integrated circuits for optical communication applicationsPommarede, Xavier 24 May 2017 (has links)
Afin de poursuivre leur montée en débit, les composants des télécommunications par fibre optique nécessitent l'élaboration de nombreuses briques de base : laser, modulateur, photo-détecteur, multiplexeur... et leur intégration avec les circuits de traitement du signal. Cette thèse a pour objectifs de concevoir et de caractériser ces différentes briques actives et passives en utilisant la technologie hybride III-V/Si. Ces briques sont ensuite utilisées dans des circuits photoniques intégrés (PIC) complets d'émission et de réception, qui présentent des avantages tels qu'une. taille réduite, une consommation et un coût de fabrication faibles. . Après une partie d'introduction, plusieurs éléments passifs sont étudiés en détail dans la 2ème partie : guides d 'ondes, virages, diviseurs de puissance, croisements de guides et hybride 90°. Tous ces dispositifs présentent de bonnes performances compatibles avec leur utilisation dans les PICs.La 3ème partie traite le problème du (dé)-multiplexage en longueur d'onde. Trois dispositifs sont étudiés : le démultiplexeur basé sur des résonateurs en anneau, des réseaux échelle et des AWG (arrayed waveguide grating). Pour les réseaux échelles, des performances à l'état de l'art ont été démontrées, d'une part sur un composant de 16 canaux séparés de 100GHz et d'autre part sur un composant de 4 canaux séparés de 20nm avec un profil aplati. Une méthode de simulation d'AWG a ensuite été présentée avec des résultats expérimentaux et théoriques à l'appui. La dernière partie traite des composants dits "actifs" et de l'intégration de toutes les fonctions précédentes dans des circuits photoniques intégrés. Les composants actifs étudiés sont les lasers, les Amplificateurs optiques en semi-conducteurs (SOA), les modulateurs à électro-absorption (EAM) et enfin les jonctions PN sur silicium comme modulateur de phase. Les PICs présentés sont d'abord deux générations de laser accordable intégré avec un EAM avec une transmission à 10Gbit/s sur 50km. Puis sont étudiés des modulateurs I/Q avec source laser accordable intégrée, d'une part avec des jonctions PN en silicium et d'autre part avec des EAM comme modulateurs pour des débits cibles de 25Gbaud/s.Une conclusion générale est tirée à la fin de la thèse. Des perspectives à court et moyen termes sont également tracées. / In order to follow the new needs in terms of optical bandwidth, optical fiber communications require the elaboration of numerous building blocks: laser, modulator, photo-detector...and their integration with signal processing circuits. This thesis has for objective the conception and caracterisation of various active and passive building blocks using the hybrid III-V/Si technology. These building blocks are then used in photonic integrated circuits (PIC) with all the necessary emission and reception functions. This enables a reduced footprint, a lower power consumption and fabrication cost.After an introduction section, several passive elements are studied in detail in the second part: waveguides, bends, power splitters, waveguide crossings and hybrid 90°. All these designs present good performances compatible with their integration in PICsThe third part treats the problem of wavelength (de)-multiplexing. Three types of device were studied: a demultiplexer based on ring resonators, echelle gratings and arrayed waveguide gratings (AWG). For the echelle gratings, state-of-the-art performances were demonstrated, first on a sample with 16 channels separated 100GHz and on the other hand a sample with 4 channels separated 20nm with a flettened profile. A simulation method for the AWG was presented with experimental and theoretical results to support the method.The last part is about "active" devices and the integration of all the previous designs in PICs. The studied active components are the lasers, semi-conductor optical amplifiers (SOA), electro-absorption modulators (EAM) and finally silicon PN junctions used as phase modulators. Two generations of a tunable laser integrated with an EAM were studied with a transmission at 10Gbit/s over 50km. The next section studied I/Q modulators with an integrated tunable laser source, using either PN silicon junction modulators or EAM with a target speed of 25Gbaud/s.A general conclusion is drawn at the end of the thesis. Short term and mid-term perspectives were also drawn.
|
32 |
MICROFLUIDIC DISPENSERS BASED ON STRUCTURALLY PROGRAMMABLE MICROFLUIDIC SYSTEMS (sPROMs)AND THEIR APPLICATIONS FOR μTASPUNTAMBEKAR, ANIRUDDHA P. 31 March 2004 (has links)
No description available.
|
33 |
AIRBORNE DATA ACQUISITION SYSTEM FOR THE RAH-66 COMANCHE AIRCRAFTCebik, James A., Connor, William J. 10 1900 (has links)
International Telemetering Conference Proceedings / October 27-30, 1997 / Riviera Hotel and Convention Center, Las Vegas, Nevada / The RAH-66 Comanche flight test program required a state of the art Airborne Data Acquisition System consisting of: 1) A modular distributed system that uses a series of software programmable building blocks capable of signal conditioning all types of sensors. 2) A digital multiplexing system capable of combining various types of digital streams at high rates including Synchronous and Asynchronous PCM, MIL-STD-1553B, and RS-422 data streams. 3) A Data Combiner Unit that accepts synchronous PCM data streams from one to eight sources at 4 MBPS or less and a frame size of up to 8128 words each that outputs four independent PCM streams at 8 MBPS or less and a frame size of up to 16384 words. 4) A Data System Control Unit that controls the tape recorder, serves as the interface to the Pilot’s Control Unit and monitors/reports status of the data acquisition system to the Pilots Control Unit. 5) An Airborne Computer that provides the control and interface to the pilot & copilot instrumentation displays. 6) A Cockpit Instrumentation Pilot Display System consisting of a Main Unit Multi- Function Display, a Load Factor/Hub Moment Display and a Right Wing Flight Control Position Display. The Main Unit Multi-Function Display has the capability to display multiple graphic pages generated by the Airborne Computer. 7) The ability to record high speed avionics buses from the (Mission Equipment Package) MEP such as MIL-STD-1553B, (High Speed Data Bus) HSDB, (Processor Interconnect) PI Bus, (Data Flow Network) DFN and PCM utilizing the Ampex DCRsi-107 Tape Recorder.
|
34 |
IMPLEMENTING A TACTICAL TELEMETRY STYSTEM FOR MULTIPLE LAUNCH ROCKET SYSTEM (MLRS) STOCKPILE RELIABILITY TESTINGCox, Corry 10 1900 (has links)
International Telemetering Conference Proceedings / October 18-21, 2004 / Town & Country Resort, San Diego, California / The Precision Fires Rocket and Missile Systems (PFRMS) Program Office continually undertakes
Stockpile Reliability Testing (SRP) to ensure the validity of the accumulated weapons and increase
the she lf life of these weapon systems. MLRS is a legacy weapon system that has been undergoing
SRP testing for over 20 years. The PFRMS Program Office has a need for a miniature Tactical
Telemetry System that will monitor the fuze performance of the MLRS Rocket during SRP testing.
This paper will address a technical approach of how a small Tactical Telemetry System could be
built to meet this requirement. The Tactical Telemetry system proposed in this paper will monitor
fuze functions, operate across the wide environmental spectrum of the SRP tests, and physically fit
in the nose area without altering the overall tactical rocket appearance or operation.
|
35 |
Multiplexeurs Accordables pour Application Spatiale / Tunable Multiplexers for Space ApplicationFeuray, William 22 December 2017 (has links)
Cette thèse a pour but d’étudier le principe d’un multiplexeur de sortie accordable pour la charge utile d’un satellite de télécommunication. La première étape consiste à analyser les principales topologies de multiplexeur de sortie utilisables et les comparer pour en retirer le meilleur candidat pour cette application. Par la suite, diverses études ont été menées sur des composants passifs imprimés en 3D plastique et métallisés de diverses manières, en cherchant à comprendre comment améliorer au mieux les résultats de ces prototypes. La dernière partie de ce manuscrit détaille la conception d’un multiplexeur à deux canaux pouvant être utilisé sur trois états différents en large bande à 19 GHz. Ces états sont créés par des bandes passantes relatives variant de 1,6 à 4,8 % et une réalisation de deux maquettes sert de preuves de concept et de performance (une en plastique métallisé et la seconde en aluminium usiné). / This thesis is about study of tunable output multiplexer principle for telecommunication satellite payload. The first step is analysis of the main topologies of output multiplexers and to compare them to conclude with the best candidate. Then, several studies were conducted on 3D plastic printed passive components with specific metallizations, searching how to improve results in term of losses and precision. Last part detailed two channels multiplexer design which can be used on three different states of relative bandwidth from 1.6 to 4.8 % at 19 GHz, and realization of two concept proof prototypes (one in metallized 3D printed plastic and another one in machined aluminum).
|
36 |
A New Approach For Distributed Amplifier DesignYilmaz, Ismail Gokhan 01 September 2012 (has links) (PDF)
In this thesis work, a new distributed amplifier topology is discussed and applied to
three different cases. The topology is based on dividing the frequency spectrum into
channels and amplifying afterwards. The channelized and amplified signals are then
combined at the output for broadband amplification. This topology is used in the design
of a three channel 0.1-1 GHz amplifier with a gain of 14.5± / 0.6 dB. The design is
fabricated, and then the measured and simulated results are compared. A second 0.1-1
GHz amplifier with 21± / 1 dB is designed in simulation environment with five channels.
This five channel amplifier is fabricated and measured results are compared with the
simulated ones. A 1-6 GHz three channel amplifier is also designed with a gain of
10.5± / 0.5 dB. Application of the proposed topology to three different designs shows
promising results for future amplifier designs.
|
37 |
Novel Quadruple-mode, Dual-mode and Dual-band Dielectric Resonator Filters and MultiplexersMemarian, Mohammad January 2009 (has links)
Dielectric resonators offer high-Q (low loss) characteristics which make them ideal for filters with narrow bandwidth and low insertion loss specifications. They are mainly used in satellite and wireless system applications. Such applications desire the highest performance filters with the lowest amount of size and mass, which has been the main motivation for size reduction techniques invented over the past three decades for these filters. In addition with the emergence of different communication system technologies, several bands are now required to be supported by a single front-end, calling for emergence and development of dual-band and multi-band filters. To date few work has been done in the area of dual-band dielectric resonator filters. Dielectric resonators filters are important components in many communication systems, when a group of such filters are brought together to perform multiplexing of RF channels. These multiplexer systems tend to be fairly complex and bulky in design, and there is strong desire to reduce their size and mass to the maximum extent possible.
Novel quadruple-mode, dual-mode, and dual-band filters as well multiplexers are presented in this thesis. The first ever quadruple-mode dielectric resonator filter using the simple cylinder structure is reported in this work. A cylindrical dielectric resonator sized appropriately in terms of its diameter and height is shown to operate as a quadruple-mode resonator, which is achieved by having two mode pairs of the structure resonate at the same frequency. Single-cavity, quad-mode filters and higher order 4n-pole filters are realizable using this quad-mode cylindrical resonator, offering significant size reduction for dielectric resonator filter applications. The structure of the quad-mode cylinder is then simplified by cutting lengthwise along the central axis of the cylinder, to produce a half-cut cylinder suitable for operation in a dual-mode regime. Novel dual-mode, 2n-pole filters are realizable using this half-cut cylinder, by making the two resonances equal in frequency. The dual-mode half-cut filter is shown to be a strong contender for replacing existing dual-mode filters used in satellite and wireless applications, as it offers superior size and mass characteristics.
By making the resonances unequal in frequency, novel dual-band filters and multiplexers are further realizable, by carrying separate frequency bands on different resonant modes of the structure. The first true orthogonal mode dual-band dielectric resonator is presented in this work, using the half-cut structure. Multiplexers are also derived from these dual-band resonators, which greatly reduce size and mass of many-channel multiplexers at the system level, as each two channels are overloaded in one physical branch.
Full control of center frequencies of resonances, input and inter-resonator couplings are achievable, allowing realization of microwave filters with different bandwidth, frequency, and return loss specifications, as well as advanced filtering functions with prescribed transmission zeros. Spurious performance of the half-cut cylinder can also be improved by cutting one or more through-way slots between opposite surfaces of the resonator. Size and mass reduction achieved by using the full and half-cut resonators described in this thesis, provide various levels of size reduction in microwave systems, both device and system level.
|
38 |
Novel Quadruple-mode, Dual-mode and Dual-band Dielectric Resonator Filters and MultiplexersMemarian, Mohammad January 2009 (has links)
Dielectric resonators offer high-Q (low loss) characteristics which make them ideal for filters with narrow bandwidth and low insertion loss specifications. They are mainly used in satellite and wireless system applications. Such applications desire the highest performance filters with the lowest amount of size and mass, which has been the main motivation for size reduction techniques invented over the past three decades for these filters. In addition with the emergence of different communication system technologies, several bands are now required to be supported by a single front-end, calling for emergence and development of dual-band and multi-band filters. To date few work has been done in the area of dual-band dielectric resonator filters. Dielectric resonators filters are important components in many communication systems, when a group of such filters are brought together to perform multiplexing of RF channels. These multiplexer systems tend to be fairly complex and bulky in design, and there is strong desire to reduce their size and mass to the maximum extent possible.
Novel quadruple-mode, dual-mode, and dual-band filters as well multiplexers are presented in this thesis. The first ever quadruple-mode dielectric resonator filter using the simple cylinder structure is reported in this work. A cylindrical dielectric resonator sized appropriately in terms of its diameter and height is shown to operate as a quadruple-mode resonator, which is achieved by having two mode pairs of the structure resonate at the same frequency. Single-cavity, quad-mode filters and higher order 4n-pole filters are realizable using this quad-mode cylindrical resonator, offering significant size reduction for dielectric resonator filter applications. The structure of the quad-mode cylinder is then simplified by cutting lengthwise along the central axis of the cylinder, to produce a half-cut cylinder suitable for operation in a dual-mode regime. Novel dual-mode, 2n-pole filters are realizable using this half-cut cylinder, by making the two resonances equal in frequency. The dual-mode half-cut filter is shown to be a strong contender for replacing existing dual-mode filters used in satellite and wireless applications, as it offers superior size and mass characteristics.
By making the resonances unequal in frequency, novel dual-band filters and multiplexers are further realizable, by carrying separate frequency bands on different resonant modes of the structure. The first true orthogonal mode dual-band dielectric resonator is presented in this work, using the half-cut structure. Multiplexers are also derived from these dual-band resonators, which greatly reduce size and mass of many-channel multiplexers at the system level, as each two channels are overloaded in one physical branch.
Full control of center frequencies of resonances, input and inter-resonator couplings are achievable, allowing realization of microwave filters with different bandwidth, frequency, and return loss specifications, as well as advanced filtering functions with prescribed transmission zeros. Spurious performance of the half-cut cylinder can also be improved by cutting one or more through-way slots between opposite surfaces of the resonator. Size and mass reduction achieved by using the full and half-cut resonators described in this thesis, provide various levels of size reduction in microwave systems, both device and system level.
|
39 |
Design and Validation of an Automated Multiunit Composting System.Pickens, Mark Everett 12 1900 (has links)
This thesis covers the design of an automated multiunit composting system (AMUCS) that was constructed to meet the experimental apparatus requirements of the ASTM D5338 standard. The design of the AMUCS is discussed in full detail and validated with two experiments. The first experiment was used to validate the operation of the AMUCS with a 15 day experiment. During this experiment visual observations were made to visually observe degradation. Thermal properties and stability tests were performed to quantify the effects of degradation on the polymer samples, and the carbon metabolized from the degradation of samples was measured. The second experiment used the AMUCS to determine the effect of synthetic clay nanofiller on the aerobic biodegradability behavior of poly (3-hydroxybutyrate-co-3-hydroxyvalerate).
|
40 |
Multiplexing NFC Antennas : An evaluation of the technique and its limitations / Multiplexande NFC AntennerGustafsson, Viktor, Ottosson, Per January 2023 (has links)
Introduction This study aims to investigate the possibility of driving multiple NFC antennas with a single NFC-controller by using a multiplexer. An artifact was developed and experiments were conducted in order to evaluate the design choice and in addition, to observe the impact of a multiplexer in an NFC system with respect to the number of successful tag detections, bit error rate (BER), the utilization of automatic antenna tuning (AAT) and the physical distance to the NFC tag. Data collected from the experiments was analyzed, and the results were discussed. The purpose of the thesis was concretized by formulating three research questions: [RQ1] How can the design proposed in the problem statement be implemented? [RQ2] How does the multiplexer impact the system’s ability to detect an NFC tag and read its contents at different distances? [RQ3] To which degree does the AAT-technology compensate for the issues caused by the multiplexer? Method This research has been conducted according to the design science research (DSR) methodology. DSR is a well-established methodology and suits the nature of this research, therefore it is used to answer the research questions. Findings The thesis demonstrates a viable solution using a multiplexer in NFC systems, with reduced detection distance as a factor to consider. The impact of AAT remains inconclusive, requiring further research. Implications This study shows that using a multiplexer in NFC systems can save costs and space, leading to more affordable and compact devices. It enables scalable, advanced NFC devices for diverse applications, encouraging wider adoption. However, developers must consider the impact of a multiplexer on detection distance when designing NFC-based applications Limitations This study has certain limitations. It focuses on a particular multiplexer and NFC antenna type, and specific testing conditions. It does not delve into the potential profitability, diverse applications, security or encryption concerns, compatibility with other devices, compliance with regulations, or hands-on verification of part connectivity.
|
Page generated in 0.0422 seconds