Sökning: "Antenna arrays"

Visar resultat 1 - 5 av 81 avhandlingar innehållade orden Antenna arrays.

  1. 1. Investigating and Enhancing Performance of Multiple Antenna Systems in Compact MIMO/Diversity Terminals

    Författare :Shuai Zhang; Sailing He; Raj Mittra; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Multiple antennas; planar inverted-F antenna; mutual coupling; slot antenna; compact antenna; mobile antenna; Q factors; antenna array; ultra-wideband UWB antenna; pattern diversity; polarization diversity; user effects; adaptive arrays; chassis mode;

    Sammanfattning : Today, owners of small communicating device are interested in transmitting or receiving various multimedia data. By increasing the number of antennas at the transmitter and/or the receiver side of the wireless link, the diversity/Multiple-Input Multiple-Output (MIMO) techniques can increase wireless channel capacity without the need for additional power or spectrum in rich scattering environments. LÄS MER

  3. 2. Embedded Element Patterns in Combination with Circuit Simulations for Multi-Port Antenna Analysis

    Författare :Kristian Karlsson; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; antenna efficiency; Greens function; multi-port antenna; impedance matching; reverberation chamber; correlation; antenna arrays; Embedded element pattern; optimization; antenna diversity;

    Sammanfattning : This thesis is a result from work on two different subjects, electromagnetic simulations of reverberation chambers and a methodology for the analysis of multi-port antennas. The subjects can be linked together by their contribution to knowledge in electromagnetic simulations and characterization of antennas. LÄS MER

  4. 3. Modeling of a Retrodirective Channel With Active Antenna Arrays for Cross-Eye Jamming

    Författare :Björn Petersson; Martin Norgren; Warren P. du Plessis; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; electronic warfare; antenna array; antenna system; radar countermeasures; jamming; cross-eye; systems modeling; system performance; systems simulation; Electrical Engineering; Elektro- och systemteknik;

    Sammanfattning : Cross-Eye (CE) jamming is a technique aimed at inducing false target angles in radar measurements. The potential to deceive monopulse radar, a radar type commonly used due to its angular accuracy and resilience against jamming, has captured the interest of Electronic Warfare (EW) system manufacturers. LÄS MER

  5. 4. Spatial diversity receivers for base station antenna arrays

    Författare :Per Pelin; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; synchronization; data reduction; spatial diversity; antenna array; finite alphabet; multi-user; iterative least squares; RAKE-combiner; reciever; base station;

    Sammanfattning : .... LÄS MER

  7. 5. On MIMO Systems and Adaptive Arrays for Wireless Communication : Analysis and Practical Aspects

    Författare :Mattias Wennström; Michael A. Jensen; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Systemteknik; antenna array; calibration; MIMO system; flat fading; non-linear amplifier; switched parasitic antenna; analog beamformer; adaptive antenna testbed; Systemteknik; Systems engineering; Systemteknik; Signal Processing; signalbehandling;

    Sammanfattning : This thesis is concerned with the use of multiple antenna elements in wireless communication over frequency non-selective radio channels. Both measurement results and theoretical analysis are presented. New transmit strategies are derived and compared to existing transmit strategies, such as beamforming and space-time block coding (STBC). LÄS MER