Search for dissertations about: "gallium nitride"

Showing result 1 - 5 of 50 swedish dissertations containing the words gallium nitride.

2. 1. Processing, Characterization and Modeling of AlGaN/GaN HEMTs

   Author : Vincent Desmaris; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; GaN; HEMT; III-Nitride processing; microwave modeling; AlGaN GaN; HFET; heterojunction field effect transistor; microwave devices; III-Nitride; Schottky diodes; Gallium nitride; resistive mixer; high electron mobility transistor; wide bandgap;

   Abstract : III-Nitrides electronic properties make them currently the materials of choice for high-power high-frequency applications. Their wide bandgaps, high breakdown fields, the high electron peak and saturation velocities combined with the large conduction band offset and the high electron mobility observed in AlGaN/GaN heterostructures enable excellent microwave power performance of AlGaN/GaN high electron mobility transistors (HEMTs). READ MORE

4. 2. Optical Guiding and Feedback in Gallium Nitride Based Vertical Cavity Surface Emitting Lasers

   Author : Seyed Ehsan Hashemi; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; antiguiding; vertical-cavity surface-emitting laser; gallium nitride laser; TiO2 high contrast grating;

   Abstract : The gallium-nitride (GaN) semiconductor material has been the core of the revolutionary breakthroughs during the last two decades in the lighting industry, by enabling manufacturing of efficient blue light emitting diodes (LEDs), for which the 2014 Nobel prize in physics was awarded. The GaN technology has further led to violet edge-emitting lasers (EELs), enabling the Blu-ray disk technology, and also to the commercialization of directly green emitting EELs. READ MORE

5. 3. Processing and characterization of GaN/SiC heterojunctions and SiC bipolar transistors

   Author : Erik Danielsson; KTH; []
   Keywords : silicon carbide; gallium nitride; device simulation; bipolar junction transistor; heterojunction; heterojunction bipolar transistor; current-voltage measurement; capacitance-voltage measurement; self-heating;

   Abstract : Silicon Carbide (SiC) and Gallium Nitride (GaN) are bothwide bandgap semiconductors that have been suggested for highpower, high voltage, and high temperature applications. Themost investigated SiC devices so far are the Schottky diode,PiN diode and the field effect transistor. READ MORE

6. 4. Extreme Implementations of Wide-Bandgap Semiconductors in Power Electronics

   Author : Juan Colmenares; Hans-Peter Nee; Leon M. Tolbert; KTH; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Cryogenic; Gallium Nitride; Gate Driver; Harsh Environments; High Efficiency Converter; High Temperature; MOSFETs; Normally- ON JFETs; Reliability; Silicon Carbide; Wide-Band Gap Semiconductors; Electrical Engineering; Elektro- och systemteknik;

   Abstract : Wide-bandgap (WBG) semiconductor materials such as silicon carbide (SiC) and gallium-nitride (GaN) allow higher voltage ratings, lower on-state voltage drops, higher switching frequencies, and higher maximum temperatures. All these advantages make them an attractive choice when high-power density and high-efficiency converters are targeted. READ MORE

7. 5. Theory and Design of Wideband Doherty Power Amplifiers

   Author : David Gustafsson; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Doherty; gallium nitride; GaN; power amplifier; MMIC; microwave; Broadband amplifiers; high efficiency; wideband;

   Abstract : The Doherty power amplifier (DPA) is one of the most popular power amplifier architectures for obtaining high average efficiency for modern communication signals with high peak-to-average power ratios (PAPR). However, the DPA suffers from often having narrowband performance which limits its capabilities in wideband and/or multi-standard microwave and radio frequency applications. READ MORE