Sökning: "mobile antennas"

Visar resultat 1 - 5 av 88 avhandlingar innehållade orden mobile antennas.

  1. 1. Decoupling and Evaluation of Multiple Antenna Systems in Compact MIMO Terminals

    Författare :Hui Li; Sailing He; Cyril Luxey; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Multiple antennas; mutual coupling; compact antennas; frequency reconfigurable antennas; pattern reconfigurable antennas; meta-material antennas; mobile antennas; fractal antennas; collocated antennas; antenna measurement.;

    Sammanfattning : Research on multiple antenna systems has been a hot topic in recent years due to the demands for higher transmission rate and more reliable link in rich scattering environment in wireless communications. Using multiple antennas at both the transmitter side and the receiver side increases the channel capacity without additional frequency spectrum and transmitted power. LÄS MER

  3. 2. Wideband Active and Passive Antenna Solutions for Handheld Terminals

    Författare :Peter Lindberg; Anders Rydberg; Anders Pers; Nicholas Buris; Uppsala universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Engineering physics; active antennas; impedance matching; dipole antennas; baluns; slot antennas; microstrip antennas; mobile antennas; multifrequency antennas; antenna proximity factors; receiving antennas; ferrite devices; Teknisk fysik;

    Sammanfattning : This thesis presents solutions and studies related to the design of wideband antennas for wireless handheld terminal applications. A method of electrically shortening the terminal chassis length to obtain resonance at high frequencies has been proposed and evaluated, thereby increasing the antennas impedance bandwidth. LÄS MER

  4. 3. Mobile Satellite Broadcast and Multichannel Communications : analysis and design

    Författare :Cristoff Martin; Björn Ottersten; Jack Winters; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Signalbehandling; communications; satellite broadcast; mobile; MIMO; asymptotic analysis; spatial multiplexing; Signalbehandling; Signal processing; Signalbehandling;

    Sammanfattning : In this thesis, analytical analysis and design techniques for wireless communications with diversity are studied. The impact of impairments such as correlated fading is analyzed using statistical models. Countermeasures designed to overcome, or even exploit, such effects are proposed and examined. LÄS MER

  5. 4. Analysis and Design of Base Station Antennas for Mobile Communications

    Författare :Björn Lindmark; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; polarization diversity; dual polarization; adaptive antennas; moment method; genetic algorithm; antenna arrays; radio propagation; channel sounding; aperture coupled patch;

    Sammanfattning : The thesis deals with base station antennas and the environment they work in. Polarization diversity, dual band operation, and adaptive antenna systems are discussed with emphasis on how antennas for these applications should be designed. We compare the polarization diversity performance of different types of dual polarized antenna elements. LÄS MER

  7. 5. Limitations on efficiency, size and bandwidth of small antennas

    Författare :Daniel Nyberg; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; log-periodic antennas; Small antennas; folded dipoles; radiation Q; fundamental limitations; bandwidth;

    Sammanfattning : The allocated space in a mobile phone for the antennas has become smaller and smaller following the size reduction of the mobile phones themselves and the integration of more functions in them. At the same time new communication systems are being planned where such small antennas also need to be wideband (UWB systems) or have multiple ports (MIMO systems). LÄS MER