Sökning: "gallium nitride GaN"

Visar resultat 11 - 15 av 43 avhandlingar innehållade orden gallium nitride GaN.

1. 11. Processing and characterization of GaN/SiC heterojunctions and SiC bipolar transistors

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

   Sammanfattning : 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. LÄS MER

3. 12. Optical Guiding and Feedback in Gallium Nitride Based Vertical Cavity Surface Emitting Lasers

   Författare :Seyed Ehsan Hashemi; Chalmers tekniska högskola; []
   Nyckelord :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;

   Sammanfattning : 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. LÄS MER

4. 13. Nonlinear Characterization of Wideband Microwave Devices and Dispersive Effects in GaN HEMTs

   Författare :Sebastian Gustafsson; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; large-signal; dispersive effects; electron trapping; thermal coupling; HEMT; GaN; microwave; wideband;

   Sammanfattning : Measurements play a key role in the development of microwave hardware as they allow engineers to test and verify the RF performance on a system, circuit, and component level. Since modern cellular standards employ complex modulation formats with wider signal bandwidths to cope with the growing demand of higher datarates, nonlinear characterization using wideband stimuli is becoming increasingly important. LÄS MER

5. 14. Optical properties of GaN and InGaN studied by time- and spatially-resolved spectroscopy

   Författare :Tomas Uždavinys; Saulius Marcinkevičius; Audrius Alkauskas; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Gallium nitride; InGaN; near-field microscopy; photoexcited carrier dynamics; intervalley energy; Fe centers; In incorporation; Physics; Fysik;

   Sammanfattning : The past decade has seen rapid expansion in the use of group III-nitride based devices. White InGaN LEDs are substituting incandescent light bulbs, space satellite industry adopting ion-radiation-resistant GaN transistors, and AlGaN deep UV LEDs are increasingly being used for water disinfection and air purification. LÄS MER

7. 15. Efficient and Wideband Load Modulated Power Amplifiers for Wireless Communication

   Författare :Han Zhou; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; GaN; energy efficiency; load modulation; Combiner synthesis; RF; wideband; Doherty; power amplifier; CLMA; SCLMA; microwave;

   Sammanfattning : The increasing demand for mobile data traffic has resulted in new challenges and requirements for the development of the wireless communication infrastructure. With the transition to higher frequencies and multi-antenna systems, radio frequency (RF) hardware performance, especially the power amplifier (PA), becomes increasingly important. LÄS MER