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 12 of 12 for “"High Frequency Signal"”.
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Ultrasound Microscope with Arbitrary Coded Broadband High Frequency Signal
Coded signals are widely used in ultrasound microscopy and they can improve signal to noise ratio and imaging quality. However, so far all reported solutions has limited bandwidth under 135 MHz. We present a solution for ultrasonic microscopy that is capable of dealing with coded GHz signals. The …
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High-Frequency Electronics for Contactless Dielectrophoresis
… This work presents two methods for providing the high-voltage and high-frequency signal necessary to generate a non-uniform electric field in the sample channel of a cDEP device. The first method, an oscillator-based system, was able to produce DEP trapping and pearl-chaining of THP-1 and MCF-7 …
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New Sensorless Permanent Magnet Synchronous Motor Drive
… operations. Among these techniques, pulsating high-frequency signal injection (PHFSI) stands out as a commonly used technique in various industrial applications. However, a significant limitation arises when applying the PHFSI technique in surface PMSMs (SPMSMs) due to the absence of magnetic …
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The role of short-term atmospheric variability in shaping Lagrangian transport in the Southern Benguela
… are averaged and saved at deferent temporal frequency: frequencies of 6 hours and 3 days. Particles released in the Lagrangian tracking tool are transported by the velocity vectors produced by the ocean model into the nursery area located at Saint Helena Bay. The presence of short-term …
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Condensed and Expanded Sections in the Lower Mesaverde Clastic Wedge, Campanian of Wyoming: Evidence for Tectonic Rectification of Sea Level
… are all affecting sea level, comparisons of high and low frequency cycles can help to sort out forcing mechanisms. Low frequency eustatic sea level rise can be amplified by regional subsidence so that high frequency sea level falls are suppressed, and the high frequency oscillations appear as …
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Development of Robust Analog and Mixed-Signal Circuits in the Presence of Process- Voltage-Temperature Variations
… especially relating to the analog and mixed-signal blocks. The proposed design techniques and circuit-level attributes are aligned with current built-in testing and self-calibration trends for integrated transceivers. In this work, the main focus is on enhancing the performances of analog and …
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High Performance Sensorless Controlled PMSM Drive with Long Cable for Subsea Applications
… gas as an energy source has led to a demand for highly efficient and reliable motors and their control. These motors are essential components of subsea applications like drilling, pumping, and boosting, which are necessary to extract natural gas and oil. The Permanent Magnet (PM) motors, known …
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Characterization and Modeling of Solar Flare Effects in the Ionosphere Observed by HF Instruments
… plays a significant role in trans-ionospheric high frequency (HF, 3-30 MHz) radiowave propagation. Solar activities, such as solar flares, radiation storms, coronal mass ejections (CMEs), alter the state of the ionosphere, a phenomenon known as Sudden Ionospheric Disturbance (SID), that can …
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Direct Torque Control for Silicon Carbide Motor Drives
… uncertainties, and external disturbances. Using higher switching frequency is generally required by DTC to reduce the torque ripples and decrease stator current total harmonic distortion (THD), which however can lower the drive efficiency. Through the use of the emerging silicon carbide (SiC) …
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Constructive utilization of intentional nonlinearity in systems of coupled micro/nanomechanical resonators
… studied in the last decade in designs of highly sensitive detection, high frequency signal-processing, and high speed switching. These designs benefit from the exceptional dynamic characteristics of these systems, i.e., high frequency resonance and high Q-factor, arising from their small …
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Coordinated active power reduction strategy for voltage rise mitigation in LV distribution network
… is from the substation to customers. However, a high penetration of rooftop solar PVs (with power levels typically ranging from 1 – 10 kW) may lead to the current flowing in the reverse direction and this could result in a sudden voltage rise. These negative impacts on the network have …
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RF micro-systems for 5G front-end signal processing
… interest in developing the next generation radio frequency (RF) front ends for more stringent requirements on performance, power consumption, and spectral utilization efficiency. More parallel RF bands and paths are added in the same form factor, along with which come more components and tighter …