Search for dissertations about: "frequency effect"

Showing result 1 - 5 of 1201 swedish dissertations containing the words frequency effect.

2. 1. Graphene field-effect transistors for high frequency applications

   Author : Muhammad Asad; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; high frequency; Graphene; transit frequency; transconductance; maximum frequency of oscillation; contact resistance; microwave electronics; field-effect transistors;

   Abstract : Rapid development of wireless and internet communications requires development of new generation high frequency electronics based on new device concepts and new materials. The very high intrinsic velocity of charge carriers in graphene makes it promising new channel material for high frequency electronics. READ MORE

4. 2. Impact of adjacent dielectrics on the high-frequency performance of graphene field-effect transistors

   Author : Muhammad Asad; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; high-frequency electronics; Graphene; transit frequency; contact resistance; MOGFETs; drift velocity; field-effect transistors; saturation velocity; maximum frequency of oscillation; diamond;

   Abstract : Transistors operating at high frequencies are the basic building blocks of millimeter wave communication and sensor systems. The high velocity and mobility of carriers in graphene can open ways for development of ultra-fast group IV transistors with similar or even better performance than that achieved with III-V based semiconductors. READ MORE

5. 3. Low frequency noise during work. Effects on performance and annoyance

   Author : Johanna Bengtsson; Göteborgs universitet; []
   Keywords : MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Low frequency noise; performance; workload; annoyance; cortisol; subjective stress; subjective sensitivity to noise; sound characteristics; frequency balance; modulation frequency;

   Abstract : Aims. Low frequency noise (LFN) is defined as "a noise with a dominant frequency content of 20 to 200 Hz". Common sources of LFN in occupational environments are ventilation, heating and air-conditioning systems, computer network installations and compressors. READ MORE

6. 4. Frequency comb Brillouin microscopy

   Author : Felipe Ademir Alemán Hérnandez; Göteborgs universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Brillouin light scattering; optics; spinwave spectroscopy; phonon spectroscopy; microscopy; Fabry-Perot interferometer; Frequency comb;

   Abstract : Brillouin light scattering (BLS), an almost a century-old technique, has evolved into a powerful and versatile method to study acoustic and magnetic phenomena down to the nanometer size scale. Presently, BLS can be applied in fields as diverse as acoustics, spintronics, geosciences, and biophysics. READ MORE

7. 5. Modelling of Terahertz Planar Schottky Diodes

   Author : Aik-Yean Tang; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; S-parameter extraction; Electro-thermal; Schottky diodes; Skin effect; Electromagnetic; Frequency multipliers; High-power frequency multiplier; Current crowding; Proximity effect; Submillimetre wave generation and detection; Geometric modelling; Gallium Arsenide;

   Abstract : This thesis deals with the modelling of THz planar Schottky diodes, focusing on analyses of the geometry- dependent parasitics and the diode chip thermal management. Moving towards higher operating frequencies, the electromagnetic couplings pose significant limitations on the diode performance. READ MORE