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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

FIELD MEASUREMENT OF FM DEVIATION

Nimrod, Daniel W. 11 1900 (has links)
International Telemetering Conference Proceedings / October 29-November 02, 1990 / Riviera Hotel and Convention Center, Las Vegas, Nevada / This paper briefly reviews past techniques for measuring FM deviation and discusses the limitations of past technology. Graphs of the Bessel functions are presented in terms of decibels (dB), offering a better method of measurement when used with a modern spectrum analyzer.
2

Building a simple spectrum analyzer with dsPIC30F4013 / Building a simple spectrum analyzer with dsPIC30F4013

Lian 连, Xiangyu 翔宇, Jiang 姜, Chunguang 春光 January 2011 (has links)
FFT-based digital spectral analyzer has become more and more widely used as a result of the development of Digital Signal Processing (DSP) techniques. Modern Analog-to-Digital Converters (ADC) and processors have made it possible to make fast measurements with a limited number of hardware.   In this thesis, a design of a simple low-cost FFT-based digital spectrum analyzer was presented. The author discusses the design of each components of the system in qualitatively and quantitatively. The report presents the whole system design in detail which contains filter design, micro-controller design, UART transmission design and MATLAB GUI design. Some satisfying measurement result of the system were presented in the paper. The system can provide fast measurement with good accuracy. But the measured result has a limited range and resolution of the display is not very high. At last, the advantages and disadvantages of the system was discussed which is considered as guidelines for further work.
3

Digitally-Assisted Mixed-Signal Wideband Compressive Sensing

Yu, Zhuizhuan 2011 May 1900 (has links)
Digitizing wideband signals requires very demanding analog-to-digital conversion (ADC) speed and resolution specifications. In this dissertation, a mixed-signal parallel compressive sensing system is proposed to realize the sensing of wideband sparse signals at sub-Nqyuist rate by exploiting the signal sparsity. The mixed-signal compressive sensing is realized with a parallel segmented compressive sensing (PSCS) front-end, which not only can filter out the harmonic spurs that leak from the local random generator, but also provides a tradeoff between the sampling rate and the system complexity such that a practical hardware implementation is possible. Moreover, the signal randomization in the system is able to spread the spurious energy due to ADC nonlinearity along the signal bandwidth rather than concentrate on a few frequencies as it is the case for a conventional ADC. This important new property relaxes the ADC SFDR requirement when sensing frequency-domain sparse signals. The mixed-signal compressive sensing system performance is greatly impacted by the accuracy of analog circuit components, especially with the scaling of CMOS technology. In this dissertation, the effect of the circuit imperfection in the mixed-signal compressive sensing system based on the PSCS front-end is investigated in detail, such as the finite settling time, the timing uncertainty and so on. An iterative background calibration algorithm based on LMS (Least Mean Square) is proposed, which is shown to be able to effectively calibrate the error due to the circuit nonideal factors. A low-speed prototype built with off-the-shelf components is presented. The prototype is able to sense sparse analog signals with up to 4 percent sparsity at 32 percent of the Nqyuist rate. Many practical constraints that arose during building the prototype such as circuit nonidealities are addressed in detail, which provides good insights for a future high-frequency integrated circuit implementation. Based on that, a high-frequency sub-Nyquist rate receiver exploiting the parallel compressive sensing is designed and fabricated with IBM90nm CMOS technology, and measurement results are presented to show the capability of wideband compressive sensing at sub-Nyquist rate. To the best of our knowledge, this prototype is the first reported integrated chip for wideband mixed-signal compressive sensing. The proposed prototype achieves 7 bits ENOB and 3 GS/s equivalent sampling rate in simulation assuming a 0.5 ps state-of-art jitter variance, whose FOM beats the FOM of the high speed state-of-the-art Nyquist ADCs by 2-3 times. The proposed mixed-signal compressive sensing system can be applied in various fields. In particular, its applications for wideband spectrum sensing for cognitive radios and spectrum analysis in RF tests are discussed in this work.
4

Development of Optoelectronic Devices and Computational Tools for the Production and Manipulation of Heavy Rydberg Systems

Philippson, Jeffrey 26 October 2007 (has links)
Experimental and theoretical progress has been made toward the production and manipulation of novel atomic and molecular states. The design, construction and characterization of a driver for an acousto-optic modulator is presented which achieves a maximum diffraction efficiency of 54 % at 200 MHz, using a commercial modulator. A novel design is presented for a highly sensitive optical spectrum analyzer for displaying laser mode structure in real time. Utilizing programmable microcontrollers to read data from a CMOS image sensor illuminated by the diffraction pattern from a Fabry-Perot interferometer, this device can operate with beam powers as low as 3.3 micro-watts, at a fraction of the cost of equivalent products. Computational results are presented analyzing the behaviour of a model quantum system in the vicinity of an avoided crossing. The results are compared with calculations based on the Landau-Zener formula, with discussion of its limitations. Further computational work is focused on simulating expected conditions in the implementation of the STIRAP technique for coherent control of atoms and molecules in the beam experiment. The work presented provides tools to further the aim of producing large, mono-energetic populations of heavy Rydberg systems. / Thesis (Master, Physics, Engineering Physics and Astronomy) -- Queen's University, 2007-10-03 17:17:56.841
5

Spektrální analyzátor N1996A-503 a nejistoty měření / Spectrum Analyser N1996A-503 and Measurement Uncertainty

Trojan, Martin January 2011 (has links)
The main target of this master’s thesis is to introduce the reader with the spectrum analyzer, Agilent N1996A CSA. This work explains all the functions of this measuring instrument, control elements and presents some technical parameters. The next part of this thesis deals with the measurement of coaxial cables, so that is why a whole chapter is devoted to coaxial cables and conductors in general. The rest of this thesis deals with issues of measurement uncertainties. This part contains the general procedure for the evaluation of uncertainty, followed by a practical part. The practical part contains measurement of distance to fault and return loss. Measurements were made on 4 samples of coaxial cable. At the end of the practical parts the measured values including the uncertainties and results are summarized in the final paragraph.
6

Wide bandwidth instantaneous radio frequency spectrum analyzer based on nitrogen vacancy centers in diamond

Chipaux, M., Toraille, L., Larat, C., Morvan, L., Pezzagna, S., Meijer, Jan Berend, Debuisschert, T. 15 August 2018 (has links)
We propose an original analog method to perform instantaneous and quantitative spectral analysis of microwave signals. An ensemble of nitrogen-vacancy (NV) centers held in a diamond plate is pumped by a 532 nm laser. Its photoluminescence is imaged through an optical microscope and monitored by a digital camera. An incoming microwave signal is converted into a microwave field in the area of the NV centers by a loop shaped antenna. The resonances induced by the magnetic component of that field are detected through a decrease of the NV centers photoluminescence. A magnetic field gradient induces a Zeeman shift of the resonances and transforms the frequency information into spatial information, which allows for the simultaneous analysis of the microwave signal in the entire frequency bandwidth of the device. The time dependent spectral analysis of an amplitude modulated microwave signal is demonstrated over a bandwidth of 600 MHz, associated to a frequency resolution of 7MHz , and a refresh rate of 4 ms. With such integration time, a field of a few hundreds of lW can be detected. Since the optical properties of NV centers can be maintained even in high magnetic field, we estimate that an optimized device could allow frequency analysis in a range of 30 GHz, only limited by the amplitude of the magnetic field gradient. In addition, an increase of the NV centers quantity could lead both to an increase of the microwave sensitivity and to a decrease of the minimum refresh rate down to a few ls.
7

Characterization and evaluation of ZigBee modules

Ramazanali, Hawar January 2006 (has links)
<p>This thesis work started with an extensive literature study in several areas, ZigBee, instruments and measuring methods. The knowledge was implemented in use with the ZigBee modules from the two manufacturers ITN and Chipcon along with ZigBee Software Stack. Measuring methods were developed and software in ZigBee software Stack was developed to use in the ZigBee modules for the measurements. Developing measurement methods and performing measurements was an iterative process for the different measurements. The aim was to characterize the ZigBee modules in the most important areas during the extent of this master thesis work.</p>
8

Characterization and evaluation of ZigBee modules

Ramazanali, Hawar January 2006 (has links)
This thesis work started with an extensive literature study in several areas, ZigBee, instruments and measuring methods. The knowledge was implemented in use with the ZigBee modules from the two manufacturers ITN and Chipcon along with ZigBee Software Stack. Measuring methods were developed and software in ZigBee software Stack was developed to use in the ZigBee modules for the measurements. Developing measurement methods and performing measurements was an iterative process for the different measurements. The aim was to characterize the ZigBee modules in the most important areas during the extent of this master thesis work.
9

Měřicí funkce spektrálního analyzátoru N1996A-503 / Funktions of Spectrum Analyser N1996A-503

Šoukal, David January 2009 (has links)
The theme of this diploma work is to introduce spectrum analzyer Agilent CSA N1996A to readers. In the work there are explained in detail all measuring functions of this machine, there are also mentioned all engineering characteristics and described all operating elements of this machine. In the diploma work is also mentioned the basice division of spectrum analyzers and their principles of activity. In the pracical part there are proposed the measurement assignments for hearers of subject MEMT, where is the possibility to use already mentioned spectrum analyzer. Including of the assignments there are also theoretical analysis of each assignment, their diagrams of wiring, practical metering and interpretation of results.
10

Spektrální analyzátor do 500 MHz / Spectrum Analyzer up to 500 MHz

Čada, David January 2015 (has links)
This project deals with design and realization of the spectrum analyser using double superheterodyne topology with frequency range up to 500MHz. This work solves hardware blocks like phase lock loops, intermediate frequency filters, saw filter, crystal filter, logarithmic detector. Content of work is also design description and tuning of spectrum analyzer parts.

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