Sökning: "waveguide"

Visar resultat 11 - 15 av 236 avhandlingar innehållade ordet waveguide.

1. 11. Silicon micromachined waveguide components for terahertz systems

   Författare :Bernhard Beuerle; Joachim Oberhammer; Umer Shah; Kamal Sarabandi; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; micromachining; waveguide; terahertz; deep reactive ion etching; silicon on insulator; on-wafer characterization; InP; SiGe; Electrical Engineering; Elektro- och systemteknik;

   Sammanfattning : This thesis presents silicon micromachined waveguide components for sub-terahertz and terahertz (THz) systems fabricated by deep reactive ion etching (DRIE). Historically the main driving force for the development of THz systems has been space-based scientific instruments for astrophysics, planetary and Earth science missions. LÄS MER

3. 12. Waveguide Finite Elements Applied on a Car Tyre

   Författare :Carl-Magnus Nilsson; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; wave equation; wave solution; waveguide; finite element; spectral finite element; tyre noise; tyre vibration; input power; shells; pre stress; fluid shell coupling; axi--symmetric;

   Sammanfattning : Structures acting as waveguides are quite common withexamples being, construction beams, fluid filled pipes, railsand extruded aluminium profiles. Curved structures like cartyres and pipe-bends may also be considered as waveguides. Wavesolutions in such structures may be found by a method calledthe Waveguide Finite Element Method or WFEM. LÄS MER

4. 13. Submillimeter-Wave Waveguide Frontends by Silicon-on-Insulator Micromachining

   Författare :Adrian Gomez-Torrent; Joachim Oberhammer; Umer Shah; Goutam Chattopadhyay; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; antenna; orthomode transducer; switch; waveguide; radiofrequency; beamforming network; submillimeter-wave; terahertz; silicon micromachining; deep reactive ion etching; silicon on insulator; Electrical Engineering; Elektro- och systemteknik;

   Sammanfattning : This thesis presents novel radiofrequency (RF) frontend components in the submillimeter-wave (sub-mmW) range implemented by silicon micromachining, or deep reactive ion etching (DRIE). DRIE is rapidly becoming a driving technology for the fabrication of waveguide components and systems when approaching the terahertz (THz) frequency range. LÄS MER

5. 14. Mid-infrared photonic devices for on-chip optical gas sensing

   Författare :Floria Ottonello Briano; Kristinn B. Gylfason; Delphine Marris-Morini; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; mid-infrared; mid-IR; photonics; silicon photonics; gas sensing; optical sensing; optical gas sensing; spectroscopy; absorption; dispersion; carbon dioxide; CO2; CO2 sensing; trace gas; ethanol sensing; alcohol sensing; waveguide; photonic waveguide; ring resonator; nanowire; nanoheater; emitter; thermal source; bolometer; microbolometer; thermal detector; high frequency; 3 omega method; plasmonic; platinum; Kanthal; silicon-on-insulator; micro-electro-mechanical systems MEMS ; microfabrication; microsystems; microtechnology; nanotechnology; Optik och fotonik; Optics and Photonics; Electrical Engineering; Elektro- och systemteknik;

   Sammanfattning : Gas detection is crucial in a wide range of fields and applications, such as safety and process control in the industry, atmospheric sciences, and breath diagnostics. Optical gas sensing offers some key advantages, compared to other sensing methods such as electrochemical and semiconductor sensing: high specificity, fast response, and minimal drift. LÄS MER

7. 15. Gap waveguide for packaging microstrip filters & investigation of transitions from planar technologies to ridge gap waveguide

   Författare :Astrid Algaba Brazalez; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; parallel plate mode; coupled line filter; microstrip circuit; packaging; Artificial magnetic conductor AMC ; perfect magnetic conductor PMC ; gap waveguide; transition.; coplanar waveguide CPW ;

   Sammanfattning : Gap waveguide technology has proved to constitute an effective alternative for the design of microwave passive components, due to its advantages with respect to traditional planar technologies and standard waveguides. There is no requirement for conductive contact between the two different metal pieces making up a gap waveguide prototype, since one of these pieces makes use of a textured surface that eliminates any possible leakage of the field through the gap to the surface of the other metal piece above it. LÄS MER