Sökning: "submillimeter imaging"

Hittade 5 avhandlingar innehållade orden submillimeter imaging.

  1. 1. Photonic terahertz-wave generation, radiation and quasioptical integration

    Författare :Biddut Kumar Banik; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; semiconductor device modelling; semiconductor diodes; III-V semiconductors; Catadioptric lens; imaging; dipole antennas; slot antennas; lens antennas; semiconductor heterojunctions; dielectric loaded antennas; optical mixers; photomixers; near-field imaging; computer aided engineering; indium compounds; millimetre wave imaging; near-field optics; submillimeter wave generation; photodiodes; terahertz sources; millimetre wave generation; submillimetre wave integrated circuits; microwave imaging; uni-travelling-carrier photodiodes;

    Sammanfattning : This thesis deals with the uni-travelling-carrier photodiode (UTC-PD) based photonic generation of terahertz waves, antenna designs for the terahertz radiation and a novelcatadioptric lens for quasioptical integration.The ongoing and accomplished research work on the UTC-PD, its limitations and optimisation scopes for attaining higher bandwidth and higher output power have been discussed. LÄS MER

  3. 2. Circumstellar Debris Disks : Observational Studies of Cold Dust and Gas Emission in Planetary Nurseries

    Författare :Ricky Nilsson; Alexis Brandeker; Mark Wyatt; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; circumstellar disks; debris disks; Kuiper belts; planet formation; submillimeter imaging; photometry; coronagraphy; integral-field spectroscopy; Astronomy; astronomi;

    Sammanfattning : Planetary systems form in disks of gas and dust surrounding newborn stars. The young circumstellar environment is characterized by frequent collisions between rocky bodies, leading to a continuous production of small dust grains. LÄS MER

  4. 3. 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

  5. 4. 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

  7. 5. Mm-wave Radio Astronomy Instrumentation for the Onsala Space Observatory and SEST

    Författare :Nicholas D. Whyborn; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; mm-wave receiver; phase retrieval holography; focal plane imaging array; radio astronomy instrumentation; SIS mixer;

    Sammanfattning : The thesis presents work done in developing instrumentation for mm- and submm-wave radio astronomy. The work described is in several fields. The greater part of the thesis is concerned with sensitive heterodyne receivers and in particular the cryogenically cooled mixers. In paper A the SEST telescope and its observing system are described. LÄS MER