Sökning: "radioastronomi"

Hittade 4 avhandlingar innehållade ordet radioastronomi.

  1. 1. Fundamental Bounds on Performance of Periodic Electromagnetic Radiators and Scatterers

    Författare :Andrei Ludvig-Osipov; B. Lars G. Jonsson; Christophe Caloz; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Q-factor; bandwidth; antenna arrays; periodic structures; physical bounds; physical limitations; Electrical Engineering; Elektro- och systemteknik;

    Sammanfattning : In this thesis, the optimal bandwidth performance of periodic electromagnetic radiators and scatterers is studied. The main focus is on the development and application of methods to obtain fundamental physical bounds, relating geometrical parameters, frequency bandwidth, efficiency and radiation characteristics of periodic electromagnetic structures. LÄS MER

  3. 2. Exploiting the Terahertz Spectrum with Silicon Micromachining : Waveguide Components, Systems and Metrology

    Författare :James Campion; Joachim Oberhammer; Umer Shah; Robert M. Weikle II; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Terahertz; Silicon Micromachining; Waveguide; Waveguide System; Metrology; Electrical Engineering; Elektro- och systemteknik;

    Sammanfattning : The terahertz spectrum (300 GHz - 3 THz) represents the final frontier for modern electronic and optical systems, wherein few low-cost, volume-manufacturable solutions exist. THz frequencies are of great scientific and commercial interest, with applications as diverse as radio astronomy, sensing and imaging and wireless communications. LÄS MER

  4. 3. 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. 4. Analysis and Optimization of Installed Antenna Performance

    Författare :Henrik Frid; B. Lars G. Jonsson; Hugh Griffiths; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Electrical Engineering; Elektro- och systemteknik;

    Sammanfattning : This Ph.D. thesis consists of six papers, which are labeled with roman numerals. Papers I-III have already been presented in a licentiate thesis published in2017, and this Ph. LÄS MER