Sökning: "Mixer"

Visar resultat 21 - 25 av 125 avhandlingar innehållade ordet Mixer.

  1. 21. Development of a Sideband Separating SIS Mixer Technology for MM-Wavelengths

    Författare :Vessen Vassilev; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; mm-wave receiver; SIS mixer; radio astronomy instrumentation; waveguide to microstrip transition; sideband separation receiver;

    Sammanfattning : This thesis presents work done in developing instrumentation for mm-wave radio astronomy. The main subject of the thesis is a sideband separating (2SB) receiver for 85-115 GHz based on a quadrature scheme with two identical SIS mixer junctions pumped by a LO applied with 90° phase difference. LÄS MER

  3. 22. Integration of Planar Antennas with MMIC Active Frontends for THz Imaging Applications

    Författare :Yogesh Karandikar; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Sub-Harmonic Resistive Mixer; Planar Antennas; Gaussian Coupling; MMIC; Gilbert Cell Mixer; THz;

    Sammanfattning : In recent years, there has been constant growth in using THz frequencies or mm, sub- mm wavelengths for various applications such as: Astronomy, Atmospheric studies, security, bio-medical imaging. All these applications are now seen more feasible due to rapid enhancements of semi-conductor processing technologies. LÄS MER

  4. 23. Mixer, Multiplier and Passive Components for Low Noise THz Receivers

    Författare :Bhushan Billade; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; millimeter wave receivers; Superconductor-Insulator-Superconductor SIS mixers; thin-film circuits.; superconducting devices; quasi-particle mixers; frequency multiplier;

    Sammanfattning : This thesis presents the work done in the field of development of low noise instruments for radio astronomy applications, and addresses some of the key components in the receiver. Part of this thesis describes the design and development of a Superconductor-Insulator-Superconductor (SIS) junction mixer covering RF frequencies from 163 to 211 GHz, reaching the quantum limited noise performance. LÄS MER

  5. 24. Numerical Studies of Mixing in Pipes and Static Mixers

    Författare :Mårten Regner; Livsmedelsteknik; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Turbulent mixing; Secondary flow; Viscosity ratio; Computational fluid dynamics; Food and drink technology; Livsmedelsteknik; Rate of striation thinning; Static mixer; Laminar mixing;

    Sammanfattning : The objective of the present work was to investigate the mixing process in static mixers under laminar flow conditions, and in pipes during the displacement of dissimilar liquids. A numerical scheme and a method of characterizing static mixers were developed. LÄS MER

  7. 25. 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