Sökning: "ferroelectric"

Visar resultat 41 - 45 av 92 avhandlingar innehållade ordet ferroelectric.

1. 41. Design and process issues of junction- and ferroelectric-field effect transistors in silicon carbide

   Författare :Sang-Mo Koo; KTH; []
   Nyckelord :;

   Sammanfattning : In today’s solid-state electronics, Si and SiO2 are thedominant materials used. However, new materials such as SiC orferroelectrics are required for some special applications sincesuperior characteristics can be achieved in electronic devices. LÄS MER

3. 42. Switchable and tunable bulk acoustic wave resonators based on BaxSr1-xTiO3 thin films

   Författare :John Berge; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Ferroelectric thin films; field induced piezoelectric effect.; tunable microwave devices; bulk acoustic wave devices; piezoelectric resonators;

   Sammanfattning : The main focus of this thesis is the study of a novel microwave component, the tunable thin film bulk acoustic wave resonator (TFBAR), based on ferroelectric BaxSr1-xTiO3 thin films. Conventional fixed frequency TFBARs, widely used for filtering applications in wireless communication systems, are based on ordinary piezoelectrics. LÄS MER

4. 43. Multi-Level Lossless Phase Modulation in Liquid Crystals for High-Speed Spatial Light Modulators

   Författare :David Engström; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; phase measurements; polarization; phase modulation; beam steering; Spatial light modulators; diffractive optics; ferroelectric liquid crystals;

   Sammanfattning : The spatial light modulator (SLM) is a compact device that enables highly precise control of light propagation with low drive voltages and no moving parts. By imposing a certain phase modulation onto the incident lightwave, functions such as multi-beam steering, beam shaping, and air turbulence corrections can be achieved in realtime. LÄS MER

5. 44. Structures and Properties of the Chiral Smectic C Liquid Crystal Phases Ferro- and Antiferroelectricity in Soft Matter

   Författare :Jan Lagerwall; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; ferroelectric liquid crystals; orientational order; smectic layer shrinkage; antiferroelectric liquid crystals; subphase suppression; confinement;

   Sammanfattning : Liquid crystals constitute a form of soft matter possessing lower symmetry than isotropic liquids but higher symmetry than solid crystals. In smectic A and C liquid crystals, the rodlike molecules are arranged in layers and the medium has crystal order in one dimension and liquid order in the other two. LÄS MER

7. 45. Dynamic and Static Diffractive Optics - some Examples

   Författare :Björn Löfving; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; subwavelength grating; spatial light modulator; phase retrieval; diffractive optics; ferroelectric liquid crystal; analog-to-digital conversion; optical switch; feedback generated hologram;

   Sammanfattning : Diffractive optics is a modern branch of optics, that exploits microstructures to manipulate the propagation of light. Fast computers and the progress in manufacturing technique of microelectronics have made possible a rapid development of diffractive optics during the past 10 years. LÄS MER