Sökning: "thermal oscillator"

Visar resultat 1 - 5 av 18 avhandlingar innehållade orden thermal oscillator.

1. 1. GaN HEMT Low Frequency Noise Characterization for Low Phase Noise Oscillator Design

   Författare :Thi Ngoc Do Thanh; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Low frequency noise; flicker noise; phase noise; deposition method.; oscillator; VCO; GaAs pHEMT; MMIC; GaN HEMT; passivation; InGaP HBT;

   Sammanfattning : The thesis presents low frequency noise (LFN) characterization of Gallium Nitride (GaN) High Electron Mobility Transistors (HEMTs) for low phase noise oscillator design. First, GaN HEMT technology is benchmarked versus other transistor technologies, e.g. LÄS MER

3. 2. Asymptotic methods applied to some oceanography-related problems

   Författare :Moundheur Zarroug; Jonas Nycander; Kristofer Döös; Jan Erik Weber; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Asymptotic analysis; internal waves; geophysical fluid dynamics; thermal oscillator; Earth sciences; Geovetenskap; Oceanography; Oceanografi; atmosfärvetenskap och oceanografi; Atmospheric Sciences and Oceanography;

   Sammanfattning : In this thesis a number of issues related to oceanographic problems have been dealt with on the basis of applying asymptotic methods.  The first study focused on the tidal generation of internal waves, a process which is quantifed by the conversion rates. These have traditionally been calculated by using the WKB approximation. LÄS MER

4. 3. Power Scaling of Highly Compact Single-Frequency Yb-Doped Fiber Amplifiers

   Författare :Enkeleda Balliu; Hans-Erik Nilsson; Magnus Engholm; Pavel Peterka; Mittuniversitetet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; single-frequency; fiber amplifier; Yb-doped fibers; stimulated Brillouin scattering; compact lasers; thermal load; SHG; MOPA;

   Sammanfattning : Both scientific interests and industrial applications have stimulated the advance of single-frequency laser technology. The high spatial and temporal coherence of this technology has facilitated many applications such as gravitational wave detection, high-precision fiber sensors, high-resolution spectroscopy, holography, and nonlinear optical conversion. LÄS MER

5. 4. Diamond Devices Based on Valley Polarization

   Författare :Nattakarn Suntornwipat; Jan Isberg; Markus Gabrysch; Saman Majdi; Hitoshi Umezawa; Uppsala universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; CVD diamond; valleytronics; Negative Differential Mobility; NDM; electron polarization; Time-of-Flight; magnetotransport; carrier transport; drift velocity; valley-transistor; Transferred-Electron Oscillator; TEO; TED; Gunn diode;

   Sammanfattning : Diamond is a wide bandgap semiconductor with extreme properties such as high thermal conductivity, high breakdown field, high carrier mobilities and chemical inertness. These properties together with the possibility to synthesize high purity Single-Crystalline (SC) diamond by Chemical Vapor Deposition (CVD), make it a very interesting material and a candidate for use in power electronics and in hazardous environments. LÄS MER

7. 5. Properties of small Bi2Sr2CaCu2O8 intrinsic Josephson junctions: confinement, flux-flow and resonant phenomena

   Författare :Sven-Olof Katterwe; Vladimir M. Krasnov; Alexey Ustinov; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; high-temperature superconductivity; intrinsic Josephson junctions; tunneling; fluxons; flux-flow oscillator; THz-emission; cavity resonances; polaritons; micro nano-fabrication; fysik; Physics;

   Sammanfattning : In this thesis, intrinsic Josephson junctions, naturally formed in the strongly anisotropic high-temperature superconductor Bi2Sr2CaCu2O8 (Bi-2212), are studied experimentally. For this purpose, small mesa structures are fabricated on the surface of single crystals using micro- and nano-fabrication tools, focused ion beam is used to reduce the area of the mesa-structures down to ≈ 1 × 1 μm2. LÄS MER