Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 35 for “"VNA"”.
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Observing the Sedimentation of TiO2 Nanoparticles in Aqueous Solution Using a Quartz Crystal Microbalance with Dissipation Monitoring
… is explored. Using a vector network analyzer (VNA) to measure harmonic ranges from the primary to the 89th harmonic of a 5 MHz crystal. The fast read and processing ability of the VNA let us monitor the change in frequency, full width at half max, and amplitude. This data allowed us to monitor …
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David versus Goliath: The Power of Weakness in Asymmetric Warfare—Lessons from History
… what conditions do violent nonstate actors (VNA) succeed against states? Why does David sometimes beat Goliath? Since at least the time of Thucydides and the Peloponnesian Wars, the realist narrative in international relations measures power primarily in relative, coercive, and deterrent …
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Novel modulated antennas and probes for millimeter wave imaging applications
… a simple and accurate vector network analyzer (VNA) for in-situ imaging applications. The concept of modulating millimeter wave antenna and scatterer structures, directly to increase the overall system sensitivity and reduce the image acquisition time, is central to the development presented …
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A calibrated dual-port acoustic Vector Network Analyser
The Vector Network Analyzer (VNA) is a workhorse in electrical engineering, and has been refined over the last fifty years to offer many advantages. This technology is continually expanding and branching into other fields including optics. This thesis presents the design and calibration of an …
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Design Of A Material Test Kit For Use From 1.6 Ghz To 26.5 Ghz And Its Use In Evaluation Of Dielectric Properties Of Foam Core Materials Used In Sandwich Composites
… an Agilent N5242-X vector network analyzer (VNA) in various bands such as R-band, S-band, C-band, G-band, C-band, X-band, P-band and K-band i.e. the dielectric properties of these materials are measured in the frequency range of 1.70 GHz to 26.5 GHz. The rectangular waveguide (RWG) is used …
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Design and Development of Planar Antennas and Dielectric Devices for use at W Band Frequencies
… were measured in the Vector Network Analyser (VNA) setup. The main body of this research consisted of the development and analysis of patch antennas. The design of back-fed and side-fed patch antennas are modelled in the CST work environment, manufactured in-house and measured with the VNA. A …
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Acoustic Vector Network Analyser
… correcting methods. A vector network analyser (VNA) is used as the data acquisition component with the aim of developing a module to allow the device to measure in the acoustic domain. The multi-microphone method employs the use of a mathematical model of the acoustics with the impedance tube to …
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Design of a Microwave Imaging System for Target Identification
… connected to a 2-port Vector Network Analyzer (VNA) using different networks of RF solid-state switches. A fully automatic data acquisition platform was developed by interfacing the VNA and the switches with a personal computer via an Arduino Uno. Our final results show that our experimental …
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Structure of Intermediate C*-subalgebras of discrete group actions
… with separable predual, every intermediate vNa $\mathcal{N}$, $L(\Gamma)\subseteq\mathcal{N}\subseteq\mathcal{M}\rtimes\Gamma$ is a crossed product vNa. Finally, we inquire into the ideal structure of intermediate $C^*$-sub-algebras $\mathcal{B}$ of the form …
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Design and Verification of a LabVIEW Automated Antenna Radiation Pattern Measurement System
… systems (AMS), a vector network analyzer (VNA) measures signals transmitted between the antenna under test (AUT) and an RF field probe within the antireflective environment of the anechoic chamber. The new system synchronizes VNA measurement with the rotation of the AUT using the automation …
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High Frequency Study of Magnetic Nanostructures
… we focused on using the Vector Network Analyzer (VNA) to measure the Ferromagnetic Resonance (FMR))of various magnetic Nanowire arrays. We employed different measurement geometries using microstripline and coplanar waveguide as microwave transmission lines.</p> <p>In part three our aim was to …
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Design of microstrip antenna based on different material properties
… fabricated the antenna. Vector Network Analyzer (VNA) used to measure the fabricated antenna to obtain the measurement result. The simulation and measurement results shows a little bit differences for both of the material substrates. Comparison between simulation and measurement result has been …
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High Bandwidth Rogowski Coils, Commutation Loop Stray Inductance, and the Si IGBT and the SiC MOSFET Based Hybrid Concept
… the Tektronix TTR500 vector network analyser (VNA). Following this, the thesis presents the design of an op-amp-based integrator, with parameters imported into LTspice for simulation. The bandwidths of the Rogowski coil-integrator assemblies are measured using the VNA, which reveals that the …
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Permeability Spectra of Electrodeposited CoFe Film for Inductor Applications
… such as SEM-EDS, EQCMB, a 4-point probe, and VNA.
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Ultra wideband antenna for microwave imaging using modified fractal structure
… parameters using vector network analyzer (VNA). The obtained results from the measurement have the bandwidth ranges from 2.2 GHz to 12GHz. The analysis of simulated and measured results shows a little deviation due to fabrication and coaxial cable losses.
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Modulation techniques for GPR system radargram
… having a fractional bandwidth of 0.46 and VNA equipment, was conducted. Based on the analysis results of the proposed PM GPR system simulation, the AFW technique produces clearer PM GPR radargram. The detection rate for PM GPR system simulation using AFW technique is 87% and 51.3% using …
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Mode conversation losses in overmolded millimeter wave transmission lines
… 0.05 + 0.02 dB with a vector network analyzer (VNA).
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Estudio de prefactibilidad para la elaboración de suplemento alimenticio a base de yacón (Smallanthus sonchifolius)
… a loan with a APR of 20%. Finally, the financial VNA was determined at S/825,210, the IRRF was 44.85%, the B/C was 1.50 and the recovery period was approximately 3 years and 8 months.
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Impact of cable bleeding towards cable characteristics and performance in VDSL2 ang g.fast technologies
… performed via Vector Network Analyzer (VNA). A series of comparative studies had been carried out especially for attenuation between ideal and faulty conditions. These attenuation results were extracted to form resistance, capacitance, inductance, and conductance (RLCG) of a transmission …
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Electromagnetic Techniques for Analysis and Design of Ultra Sensitive Receivers for Far-Infrared Astronomy
… size to suit the frequency range of the in-house VNA (vector network analyser) system at NUIM (National University of Ireland, Maynooth). The main drivers for the work presented in this thesis were two Technology Research Programmes, both commissioned by ESA (European Space Agency).
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