Sökning: "sub 6 GHz"

Visar resultat 1 - 5 av 15 avhandlingar innehållade orden sub 6 GHz.

  1. 1. Massive MIMO From a Terminal Perspective

    Detta är en avhandling från Department of Electrical and Information Technology, Lund University

    Författare :Erik L Bengtsson; Lunds universitet.; Lund University.; [2019-09-03]
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Massive MIMO; mm-wave; terminal antenna; channel sounding; Propagation Channel; sub 6 GHz;

    Sammanfattning : This thesis focuses on the terminal aspects of massive MIMO systems. Based on the degree of freedom a terminal have in a MaMi, different antenna configurations, transceiver topologies with associated transmission schemes, and the underlying algorithms are researched. LÄS MER

  2. 2. Low Noise SIS Mixers and Cryogenic Amplifiers for Sub-Millimeter Astronomy

    Detta är en avhandling från Department of Electrical and Information Technology, Lund University

    Författare :Christophe Risacher; [2005]
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

    Sammanfattning : This PhD thesis presents the work that was done developing radioastronomy instrumentation. The first part of this work deals with 2-stage low-noise cryogenic amplifiers using commercial GaAs HEMT transistors for frequency bnads: 3.4-4.6 GHz, 4-8 GHz and 8-9 GHz. LÄS MER

  3. 3. Nonlinear optics in KTiOPO4 for spectral management of ultra-short pulses in the near- and mid-IR

    Detta är en avhandling från KTH Royal Institute of Technology

    Författare :Anne-Lise Viotti; KTH.; [2019]
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Nonlinear optics; Ferroelectrics; Physics; Fysik;

    Sammanfattning : This thesis explores the possibilities of controlling nonlinear optical interactions in ferroelectric materials for bandwidth tailoring of ultrashort pulses in the pico- and femto-second range. The control is achieved through quasi-phase matching, which is based on alternating the material’s spontaneous polarization into different domains. LÄS MER

  4. 4. Resonant switching and vortex dynamics in spin-flop bi-layers

    Detta är en avhandling från Stockholm : KTH

    Författare :Sergiy Cherepov; KTH.; [2010]
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; spin-dynamics; MRAM; vortex; switching; NATURAL SCIENCES Physics Condensed matter physics; NATURVETENSKAP Fysik Kondenserade materiens fysik; NATURAL SCIENCES Physics Condensed matter physics Magnetism; NATURVETENSKAP Fysik Kondenserade materiens fysik Magnetism; NATURAL SCIENCES Physics Condensed matter physics Mesoscopic physics; NATURVETENSKAP Fysik Kondenserade materiens fysik Mesoskopisk fysik;

    Sammanfattning : This thesis is a study of the static and dynamic behavior of the magne-tization in spin-flop bi-layers, which consist of two soft ferromagnetic layerscoupled by dipolar forces through a thin nonmagnetic spacer. The focus ofthe work is three fold: collective spin dynamics in the anti-parallel groundstate; resonant switching in the presence of thermal agitation; and static anddynamic behavior of the system in the vortex-pair state, with a particularemphasis on the interlayer core-core interaction. LÄS MER

  5. 5. Spectrally Precoded OFDM-Design and Analysis

    Detta är en avhandling från Luleå : Luleå University of Technology

    Författare :Medhat Mohamad; Luleå tekniska universitet.; [2019]
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; OFDM; spectral precoding; out of band emission; 5G; Signalbehandling; Signal Processing;

    Sammanfattning : Despite shifting towards mm-wave bands, the sub-6 GHz band will continue to be a fundamental spectral band in 5G. However, the severe congestion in this band makes a well-constrained spectrum a critical requirementof 5G. LÄS MER