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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

A 50 MHz FMCW radar for the study of E-region coherent backscatter

Cooper, Joel 03 July 2006
A 50~MHz E-region coherent backscatter radar was designed based on frequency modulated continuous wave (FMCW) radar techniques. This thesis presents the theory behind the FMCW technique and its implementation in a practical radar system. The system was designed and constructed at the University of Saskatchewan and was field tested at a radar site a few kilometres from the university. This thesis demonstrates that an FMCW radar is technically possible and functional as a research tool for E-region coherent backscatter studies. <p>The primary goal of this research is to develop a better understanding of the plasma processes responsible for the radar echoes. FMCW techniques offer a compromise between the pulsed and continuous wave (CW) radar techniques, which have previously been used for E-region experiments. CW techniques provide excellent spectral measurements but are limited in their ability to determine range information. Pulsed techniques offer excellent range resolution but may be limited in their ability to make detailed high resolution Doppler measurements of E-region radar backscatter. The implementation of FMCW techniques provides a simple and effective method of simultaneously obtaining excellent Doppler and range measurements.<p> The use of FMCW techniques is a novel approach to E-region coherent backscatter studies. Data analysis techniques were developed to extract the range and Doppler information from FMCW radar echoes. In the first few months of operation, the radar observed all four typical E-region radar signatures, Type I to Type IV, plus meteor trail echoes. Observations of each type of radar echo are presented, without interpretation, to illustrate the performance of the radar.
2

A 50 MHz FMCW radar for the study of E-region coherent backscatter

Cooper, Joel 03 July 2006 (has links)
A 50~MHz E-region coherent backscatter radar was designed based on frequency modulated continuous wave (FMCW) radar techniques. This thesis presents the theory behind the FMCW technique and its implementation in a practical radar system. The system was designed and constructed at the University of Saskatchewan and was field tested at a radar site a few kilometres from the university. This thesis demonstrates that an FMCW radar is technically possible and functional as a research tool for E-region coherent backscatter studies. <p>The primary goal of this research is to develop a better understanding of the plasma processes responsible for the radar echoes. FMCW techniques offer a compromise between the pulsed and continuous wave (CW) radar techniques, which have previously been used for E-region experiments. CW techniques provide excellent spectral measurements but are limited in their ability to determine range information. Pulsed techniques offer excellent range resolution but may be limited in their ability to make detailed high resolution Doppler measurements of E-region radar backscatter. The implementation of FMCW techniques provides a simple and effective method of simultaneously obtaining excellent Doppler and range measurements.<p> The use of FMCW techniques is a novel approach to E-region coherent backscatter studies. Data analysis techniques were developed to extract the range and Doppler information from FMCW radar echoes. In the first few months of operation, the radar observed all four typical E-region radar signatures, Type I to Type IV, plus meteor trail echoes. Observations of each type of radar echo are presented, without interpretation, to illustrate the performance of the radar.
3

Design of Pulse Output Direct Digital Synthesizer with an Analog Filter Bank

Pothuri, Aditya R. 22 July 2008 (has links)
No description available.
4

COMPLEX WAVEFORM GENERATION UTILIZING FIELD PROGRAMMABLE GATE ARRAYS

James, Calvin L. 10 1900 (has links)
International Telemetering Conference Proceedings / October 27-30, 1997 / Riviera Hotel and Convention Center, Las Vegas, Nevada / The basic building blocks for implementing complex waveform generators using a look-up table approach are random access memory (RAM) and read only memory (ROM) devices. Due to technological advancements in field programmable gate array (FPGA) development, these devices have the ability to allocate large amounts of memory elements within the same structure. The self containment property makes the FPGA a suitable topology for complex waveform generation applications. In addition, this self containment property significantly reduces implementation costs by reducing the number of external components required to support many applications. This paper examines the use of FPGA’s in various complex waveform generation applications. In particular, a discussion will ensue examining possible mappings of the time domain response of the complex waveform into memory elements of the FPGA. The analyses and examples contained in the sequel are from existing waveform generation applications, developed for Gauissian Minimum Shift Keying (GMSK) and Unbalanced Quadriphase Shift Keying (UQPSK) modulation formats.
5

The chemical and biochemical basis of dapsone toxicity

Mahmud, Roziahanim January 1996 (has links)
No description available.
6

DIRECT DIGITAL FREQUENCY SYNTHESIZER ARCHITECTURE FOR WIRELESS COMMUNICATION IN 90 NM CMOS TECHNOLOGY

Nguyen, Tri Trong 08 April 2011 (has links)
No description available.
7

FLIGHT LINE TEST SET, IRIG TONE GENERATOR AND FLIGHT TERMINATION TRANSMITTER ON A PC CARD

Cirineo, Tony 10 1900 (has links)
International Telemetering Conference Proceedings / October 27-30, 1997 / Riviera Hotel and Convention Center, Las Vegas, Nevada / This paper describes the development of a PC based IRIG tone generator and flight termination transmitter. The tone generator and flight termination transmitter card are part of a flight line test set. The test set has several PC based cards which include an S-Band telemetry receiver, a bit synchronizer, a decommutator, an encryption support card and the flight termination transmitter card. The test set can perform a complete end to end test of a weapon’s flight termination system prior to loading on an aircraft.
8

The development of a systematised decision process for optimising water allocation plans in Egypt

Ahmed, Tarek Abdallah January 1995 (has links)
No description available.
9

Zjišťování diabetes distres syndrómu u českých pacientov s diagnózou diabetes mellitus / Detection of diabetes distress syndrome in Czech patients diagnosed with diabetes mellitus

Povrazníková, Monika January 2020 (has links)
Literature review part of this thesis focuses on the diabetes mellitus diagnosis and its negative effects on mental health and social relationships of diagnosed patients in form of diabetes distress. The research part investigates change of diabetes distress measured by Diabetes distress scale (DDS) and glycated haemoglobin HbA1c in the beginning, at the end and 6 months after the end of the group educational course. The group consisted of 66 Czech people diagnosed with type 2 diabetes (mean age 62 years, SD = 9,77; median = 63,5). Increased diabetes distress (DDS value ≥ 2) in the 1st measurement of DDS was reported by 15 people out of 52 (29%). There was a significant decrease in HbA1c from the beginning to the end of the course (χ2 (2) = 22.5; p <0,001) and this low level was maintained even after 6 months after the course. A non-significant reduction in diabetes distress between 1st and 2nd measurement was observed in 45 subjects (W = 509; p = 0,098). A statistically significant reduction in diabetes distress was observed between the 1st and 2nd DDS measurement only in those 23 subjects (χ2 (2) = 9,50; p = 0,002) who also participated in 3rd DDS measurement - further research in this area would be appropriate. In our sample, no significant difference was found between the sexes, DDS and HbA1c,...
10

APPROACH FOR A WIDE DEVIATION RF PHASE MODULATOR on a 6U-VME-CARD

Weitzman, Jonathan M 10 1900 (has links)
International Telemetering Conference Proceedings / October 26-29, 1998 / Town & Country Resort Hotel and Convention Center, San Diego, California / A Phase Modulator combining digital techniques with non-traditional analog circuitry can minimize the shortcomings of a traditional (purely analog) Phase Modulator. These shortcomings are: nonlinear response from input modulating signal to output modulated signal; parameters (frequency and modulation index) that are difficult to set; and the need for complex filters. The design approach discussed in this paper uses a combination of Direct Digital Synthesis (DDS) and analog devices operating in their linear range to generate a Phase Modulated RF (140 MHz) signal. A Numerically Controlled Oscillator (NCO) digitally generates the first IF yielding a very accurate, repeatable and linear signal with easily adjustable parameters such as frequency and modulation index. Linear multipliers (instead of saturated diode mixers or step recovery diodes) are used for up-conversion to RF. Using linear multipliers eases the filtering requirements due to the significantly reduced harmonics and IM (Inter-Modulation) terms. The resulting RF signal is easily translated to higher frequency bands such as L, S, C, X or K.

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