Search for dissertations about: "GaAs"

Showing result 16 - 20 of 234 swedish dissertations containing the word GaAs.

2. 16. Optical studies of crystal phase heterostructures

   Author : Irene Geijselaers; NanoLund: Centre for Nanoscience; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; III-V semiconductor nanowires; photoluminescence; photoluminescence excitation; polytype; crystal phase heterostructure; InP; GaAs; wurtzite; Fysicumarkivet A:2021:Geijselaers;

   Abstract : III-V semiconductors are commonly used for a variety of optical applications, such as LED based lights and solar sells. Most III-V semiconductors, such as GaAs and InP, exhibit the zinc-blende (zb) crystal structure, but in the form of nanowires it is also possible to create them in the wurtzite (wz) crystal structure. READ MORE

4. 17. Nonlinear Modeling of FETs for Microwave Switches and Amplifiers

   Author : Ankur Prasad; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; HEMT; symmetry; small-signal model; field-plate.; GaAs; GaN; nonlinear model; trap model; symmetrical model; trap; model;

   Abstract : The exponential growth in wireless systems require rapid prototyping of radio frequency circuits (RF) using computer-aided design (CAD) enabled models. Most of the RF circuits (e.g. switches, amplifiers, mixers, etc. READ MORE

5. 18. Composite Nanostructured Materials for Renewable Energy Applications

   Author : Elfatih Mohammed Mustafa; Omer Nur; Magnus Willander; Malik Maaza; Linköpings universitet; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Solar energy; Photocatalysis; Solar cells; Nanostructured materials; ZnO; CuO; Ta2O5; GaAs;

   Abstract : Diverse sources of energy are becoming increasingly significant in today's world. The most common source of energy today is fossil fuels, such as coal, oil, and gas. While this energy source has many advantages, it also comes with many problems. READ MORE

6. 19. Design of High Linearity MMIC Power Amplifiers for Space Applications

   Author : Oliver Silva Barrera; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; pHEMT; GaAs; reliability; Power amplifier; non-linear modeling; Junction temperature; C-Band; Infrared measurements;

   Abstract : The high linearity performance in satellite transmitters is receiving increasing attention due to the demands of higher data rates in satellite communication links. During the last decade, digital communication links in satellite system have been replacing the previous analog links increasing the channel efficiency by allocating multiple carriers in the transponder bandwidth. READ MORE

7. 20. Integrated VCOs in Gallium Arsenide HEMT technologies with a novel varactor structure

   Author : Mattias Ferndahl; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; design; Oscillator; HEMT; pHEMT; MMIC; VCO; varactor; GaAs; mHEMT;

   Abstract : This thesis presents results on metamorphic and pseudomorpic GaAs HEMT based Voltage Controlled Oscillators and a novel high-Q varactor structure, used in the VCOs, together with a straightforward extraction procedure for the varactors.Theory and fundamentals around LC-oscillators with oscillator criteria, phase noise and different topologies are given as background together with VCO phase noise measurement methods and an overview on device flicker noise; its physical origin and measurement. READ MORE