Sökning: "Submillimeter"

Visar resultat 1 - 5 av 41 avhandlingar innehållade ordet Submillimeter.

1. 1. 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

3. 2. Radioastronomy Instrumentation for Herschel and APEX Projects

   Författare :Miroslav Pantaleev; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; beam measurements; quasioptics; optical alignment; submillimeter; HEB mixer;

   Sammanfattning : This thesis presents work done in developing instrumentation for sub-mm radio astronomyprojects.The first part covers Gaussian beam measurements for the Heterodyne Instrument for Far-Infrared (HIFI) of the Herschel Space Observatory project by the European Space Agency. LÄS MER

4. 3. Studies in Molecular Astrophysics and Astrobiology

   Författare :Eva Wirström; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Submillimeter; Radio lines: ISM; Astrobiology; ISM: individual objects: Orion KL; Molecular data; ISM: molecules;

   Sammanfattning : The molecules of the interstellar medium (ISM) can be used as probes of the physical conditions in a range of different types of interstellar environment, for example star forming regions. The first chapters of this thesis describe the theory and the observational techniques used to study the rotational transition emission from, and the present knowledge of, these molecules. LÄS MER

5. 4. InP DHBT Amplifiers and Circuit Packaging up to Submillimeter-Wave Frequencies

   Författare :Klas Eriksson; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; InP; WR05; packaging; noise figure; substrate modes; WR03.; multiple layer interconnect; double heterojunction bipolar transistor DHBT ; G-band; wideband; H-band; waveguide transition; distributed amplifier DA ; millimeter-wave; amplifier; low-noise amplifier LNA ; membrane technology; waveguide module; submillimeter-wave;

   Sammanfattning : This thesis treats the design and characterization of amplifiers operating up tosubmillimeter-wave frequencies and packaging of such circuits into waveguidemodules. The circuits use an advanced indium phosphide (InP) double heterojunctionbipolar transistor (DHBT) process with a multilayer back-end. LÄS MER

7. 5. On millimeter and submillimeter wave focal plane arrays implemented with MEMS waveguide switches

   Författare :Henrik Frid; Joachim Oberhammer; Vessen Vassilev; Mikro- och nanosystemteknik KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Extended Hemispherical Lens; Beam Steering; Focal Plane Array FPA ; Ray-Tracing; RF MEMS; waveguide switch; micromachined waveguide; submillimeter-wave; rectangular waveguide; terahertz; lenses; antenna theory; silicon; Electrical Engineering; Elektro- och systemteknik;

   Sammanfattning : This thesis presents research towards enabling micromachined millimeter and submillimeter wave focal plane arrays (FPAs). The FPAs operate under the following principle: a switch network consisting of microelectromechanical (MEMS) switches, integrated with micromachined waveguides, is used to feed an array of antenna elements, located in the focal plane of a high-gain quasi-optical system. LÄS MER