Global ETD Search

11	Construction Of An Experimental Radar System Kilicoglu, Nezaket 01 December 2010 (has links) (PDF) In this thesis, an Experimental Radar System is designed and constructed for use in experimental radar studies such as clutter measurement and target detection, both in the laboratory and outdoor. COTS laboratory equipments are utilized as hardware elements of the radar and MATLAB is used as signal processing and user interface software tool. Vector signal generator (as transmitter), spectrum analyzer with vector signal analysis (as receiver), a high power amplifier, a low noise amplifier, horn antennas and a computer are the hardware units of the system. Various transmit signals are generated and pulse Doppler processing is performed at the receiver side. The system is controlled through the user interface which runs on a PC.
12	DWDM v přístupových sítích / DWDM in access networks Šifta, Radim January 2011 (has links) The aim of this master´s thesis is an explanation of the problem of optical access networks with wavelength division multiplex, main purpose is to demonstrate the difference between simulation and real measurement. The thesis is divided into several basic thematic areas. At the beginning of thesis is outlined the basic division of multiplexing system, there are discussed the basic solutions of wavelength multiplexes and their possible combinations. The next chapter deals with the active elements, which are an essential part of xWDM systems such as optical lasers, detectors and amplifiers. The following chapter is focused on the passive elements, especially on the passive filters, which form a key part of the wavelength multiplex. Methods of measurement C/DWDM networks are discussed in the next part of thesis. The next chapter describes the topology used by active and passive optical networks. Penultimate part of this thesis consists of designs simulated models PON and WDM-PON networks and comparing their transmission parameters. The final part presents the results of practical measurements of experimental optical access network with wavelength division multiplex, the results are simultaneously compared with results of simulations.
13	Komunikační rozhraní pro ovládání spektrálního analyzátoru / Communication Environment for Spectral Analyzer Control Smělík, Martin January 2011 (has links) The aim of this master‘s thesis was design a new communication interface for spectral analyzer Seaward EMC Spectrum Receiver, which instead of the RS 232 interface is connected to a computer via the USB interface. This thesis contains both hardware and software solution based on the analysis and comprehensive understanding of communication between the spectrum analyzer and the computer. Further it contains the whole realization of communication interface and an example of measurement of the EMC problems too. Last part of this thesis was a realization of the automatic measurement via the development environment MATLAB and Agilent VEE, which was used for measurement of noise background.
14	Frequency Comb Experiments and Radio Frequency Instrumentation Analysis for Optical Atomic Clocks Ryan J Schneider (14187461) 29 November 2022 (has links) <p>Space-based global navigation and precision timing systems are critical for modern infrastructure. Atomic clock technology has increased the precision of these systems so that they are viable for military operations, navigation, telecommunications, and finance. Advances in optical atomic clocks, based on optical frequencies, provide an opportunity for even more precise timing. Therefore, developments in chip-scale optical atomic clock technologies could lead to increased and more wide-spread application of this precision timing. One component of the optical atomic clock is the optical frequency comb which serves as an interface between optical and microwave frequencies. This thesis will cover experiments related to these optical frequency combs. A 2$\mu$m fiber laser was developed in order to test second harmonic devices required to stabilize an optical frequency comb. The laser was then employed to measure the operating wavelengths and efficiencies of non-linear devices. In addition, an analysis of the radio frequency instruments used to evaluate microwave outputs was conducted to determine whether a digital signal analyzer (oscilloscope) or an analog electronic spectrum analyzer provides more accurate results for optical frequency comb based experiments.</p> Optical Atomic Clock Optical Frequency Comb Tunable Fiber Laser Second Harmonic Generation Digital Signal Analyzer Electronic Spectrum Analyzer
15	Poly-Vinylidene Fluoride Based Vibration Spectrum Sensors and Energy Harvestors Nyayapati, Mahidhar Ramesh January 2014 (has links) (PDF) Mechanical vibrations in large structures such as buildings, bridges, dams and critical frequencies in large machinery generally have low frequencies (100Hz-1000Hz). To monitor large areas of such structures we need huge network of low cost, easily manufacturable, self-powered and stand-alone vibration spectrum sensors. The sensors should also consume very little power during their overall operation cycle and have moderately high frequency resoultion. The thesis provides mathematical analysis, design and development of stand-alone, low frequency vibration spectrum analyzer .A mechanically stretched polymer piezoelectric membrane, which has a fixed length and tension, can act as a single frequency detector due to its unique resonant frequency. Stretching multiple ribbons of diffferent lengths and tensions, a vibration spectrum analyzer, which gives the Fourier frequency components present in an arbitrary mechanical input vibration, can be designed. The thesis presents a detailed description of experiments to evaluate a low frequency vibration spectrum analyzer system that accepts an incoming input vibration and directly provides the spectrum as output. Polymer piezoelectric materials being easily manufacturable these sensors can be deployed in wide area sensor networks that monitor large structures. The thesis also shows design of a vibration energy harvesting system based on the concept of harvesting energy at low frequencies. The need for developing such an energy harvesting system arises from the necessity of making the vibration sensor, self-powered. Multiple experimental tests were performed before developing a prototype vibration energy harvesting circuit. Vibration Spectrum Sensors Vibration Energy Harvestors Piezoeletricity Vibration Spectrum Analyzer Polymer Piezoelectric Materials Mechanical Vibrations Poly-Vinylidene Difluoride(PVDF) Vibration Sensing Energy Harvesting Energy Harvestors Vibration Spectrum Sensing Harvesting Energy Vibration Energy Harvesting System Materials Science
16	Digitálně řízený audio zesilovač ve třídě D s dálkovým ovládáním / D class audio-amplifier with digital and remote control Petrgál, Filip January 2014 (has links) The contents of this thesis is design of audio power amplifier in Class D with fully digital control and remote control and is divided into two parts . The first part is devoted to the basic principles and theory of key elements of the entire amplifier. The second part consists of a complete description of the design and construction of a power amplifier, digital control with remote control, a spectrum analyzer, equalizer, preamp VU meters and complete power supply. Each proposal contains a detailed analysis of the solutions supported by simulations and software. For individual parts have been completely measured p arameters.
17	Novel Devices and Components for THz Systems Middendorf, John Raymond 23 May 2014 (has links) No description available. Electrical Engineering Electromagnetics Engineering Optics Physics Plasma Physics Radiation Materials Science photoconductive switch ultrafast photoconductivity Gallium Arsenide THz extrinsic photoconductivity Fabry-Perot THz spectrum analyzer THz polarizer Structured-surface plasmons spoof-surface plasmons high fill factor
18	Mikromechanisches kraftgekoppeltes Sensor-Aktuator-System für die resonante Detektion niederfrequenter Schwingungen / Micro-mechanical force-coupled sensor-actuator-system for the resonant detection of low frequency vibrations Forke, Roman 25 January 2013 (has links) (PDF) Die vorliegende Arbeit beschreibt die Entwicklung und Charakterisierung eines mikromechanischen kraftgekoppelten Schwingsystems für die resonante Detektion niederfrequenter Schwingungen. Es wird ein neuartiges Prinzip vorgestellt, das es ermöglicht, niederfrequente Vibrationen frequenzselektiv zu erfassen. Mittels Amplitudenmodulation wird das niederfrequente Signal in einen höheren Frequenzbereich umgesetzt. Durch Ausnutzung der mechanischen Resonanzüberhöhung wird aus dem breitbandigen Signal ein schmales Band herausgefiltert, die anderen Frequenzbereiche werden unterdrückt. Auf diese Weise wird direkt die spektrale Information des niederfrequenten Signals gewonnen. Eine Fourier-Transformation ist hierbei nicht notwendig. Die Abstimmung des Sensors erfolgt über eine Wechselspannung und führt dadurch zu einer einfachen Auswertung. Die Schwerpunkte der Arbeit liegen in den theoretischen Untersuchungen zum neuartigen Sensorprinzip, in der Entwicklung einer mikromechanischen Sensorstruktur zum Einsatz des neuen Prinzips sowie in der Entwicklung und Charakterisierung eines Messsystems zur Detektion niederfrequenter mechanischer Schwingungen mit dem neuen Sensor. / This thesis describes the development and characterization of a micromechanical force coupled oscillator system for the resonant detection of low frequency vibrations. It presents a novel working principle that enables spectral measurements of low frequency vibrations. The low frequency spectral content is converted into a higher frequency range by means of amplitude modulation. Due to the mechanical resonance a narrow band is filtered out of the wide band vibration signal. The remaining frequency content is suppressed. Hence, the spectral information is directly obtained with the sensor system without a fast Fourier transform. The tuning is done with an AC voltage resulting in a simple analysis. The main focuses of the work are the theoretical analysis of this novel sensor principle, the development of the micromechanical sensor structure for the use of the novel principle as well as the development and characterization of a measurement system for the spectral detection of low frequency mechanical vibrations with the developed sensor system. Mikrotechnologie elektromechanische Modulation kraftgekoppelte Schwinger resonante Schwingungsdetektion Breitbandschwinger frequenzselektiv kapazitiv BDRIE Systemsimulation mechanischer Spektrumanalyzer microtechnology MEMS condition monitoring electro mechanical modulation force coupled oscillator resonant vibration detection resonator wideband damping capacitive detection BDRlE technology vibration sensor wafer level test system simulation mechanical spectrum analyzer ddc:600 ddc:620 ddc:629 MEMS Zustandsüberwachung Resonator Dämpfung Vibrationssensor Charakterisierung
19	Skener elektromagnetických polí a jeho využití při měření elektromagnetické kompatibility / Electromagnetic field scanner and its utilization in EMC measurement Chupáč, Michal January 2013 (has links) Master’s thesis is focused on making the acquaintance of EMC issues and ways of electromagnetic field scanner RS321 utilization for pre-compliance measurements. First part contains analysis of available equipment’s influence on measurement results on the basis of gathered specification. Next part includes an example measurement used as operational manual for scanner and its controlling program. The most important part is correction evaluation for performed EMI measurement of signal generator using its EMC certification protocol and application of gained correction curve on independent EMI measurement of device tested by EMC testing laboratory. Other possibilities of scanner utilization are mentioned in the next chapters. Last part of the thesis contains suitability evaluation of EMC scanner on the basis of findings from performed measurements.
20	Mikromechanisches kraftgekoppeltes Sensor-Aktuator-System für die resonante Detektion niederfrequenter Schwingungen Forke, Roman 23 November 2012 (has links) Die vorliegende Arbeit beschreibt die Entwicklung und Charakterisierung eines mikromechanischen kraftgekoppelten Schwingsystems für die resonante Detektion niederfrequenter Schwingungen. Es wird ein neuartiges Prinzip vorgestellt, das es ermöglicht, niederfrequente Vibrationen frequenzselektiv zu erfassen. Mittels Amplitudenmodulation wird das niederfrequente Signal in einen höheren Frequenzbereich umgesetzt. Durch Ausnutzung der mechanischen Resonanzüberhöhung wird aus dem breitbandigen Signal ein schmales Band herausgefiltert, die anderen Frequenzbereiche werden unterdrückt. Auf diese Weise wird direkt die spektrale Information des niederfrequenten Signals gewonnen. Eine Fourier-Transformation ist hierbei nicht notwendig. Die Abstimmung des Sensors erfolgt über eine Wechselspannung und führt dadurch zu einer einfachen Auswertung. Die Schwerpunkte der Arbeit liegen in den theoretischen Untersuchungen zum neuartigen Sensorprinzip, in der Entwicklung einer mikromechanischen Sensorstruktur zum Einsatz des neuen Prinzips sowie in der Entwicklung und Charakterisierung eines Messsystems zur Detektion niederfrequenter mechanischer Schwingungen mit dem neuen Sensor. / This thesis describes the development and characterization of a micromechanical force coupled oscillator system for the resonant detection of low frequency vibrations. It presents a novel working principle that enables spectral measurements of low frequency vibrations. The low frequency spectral content is converted into a higher frequency range by means of amplitude modulation. Due to the mechanical resonance a narrow band is filtered out of the wide band vibration signal. The remaining frequency content is suppressed. Hence, the spectral information is directly obtained with the sensor system without a fast Fourier transform. The tuning is done with an AC voltage resulting in a simple analysis. The main focuses of the work are the theoretical analysis of this novel sensor principle, the development of the micromechanical sensor structure for the use of the novel principle as well as the development and characterization of a measurement system for the spectral detection of low frequency mechanical vibrations with the developed sensor system. info:eu-repo/classification/ddc/600 ddc:600 info:eu-repo/classification/ddc/620 ddc:620 info:eu-repo/classification/ddc/629 ddc:629

Search results