Sökning: "antenna array"

Visar resultat 1 - 5 av 127 avhandlingar innehållade orden antenna array.

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

    Författare :Shuai Zhang; Sailing He; Raj Mittra; KTH; []
    Nyckelord :ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; 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

  2. 2. Sparse Array Synthesis of Complex Antenna Elements

    Författare :Carlo Bencivenni; Chalmers University of Technology; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; mutual coupling; array signal processing; maximally sparse array; aperiodic array; symmetric layout.; phase scanning; compressive sensing;

    Sammanfattning : Arrays of antennas can significantly improve the performances and extend the capabilities of single-element antennas. However, antenna arrays are expensive solutions and therefore it is critical to keep the costs to a minimum. LÄS MER

  3. 3. Next Generation Wideband Antenna Arrays for Communications and Radio Astrophysics

    Författare :Christos Kolitsidas; Lars Jonsson; Christophe Craeye; KTH; []
    Nyckelord :ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; array figure of merit; fundamental limits; wideband array; wide scan-angle array; strongly coupled asymmetric dipole array; periodic loading; soft Vivaldi array; 21cm Cosmology; Epoch of Reionization; Electrical Engineering; Elektro- och systemteknik;

    Sammanfattning : Wideband, wide-scan antenna arrays are a promising candidate for the future wireless networks and as well as an essential part of experimental radio astrophysics. Understanding the underline physics of the element performance in the array environment is paramount to develop and improve the performance of array systems. LÄS MER

  4. 4. Antenna array mapping for DOA estimation in radio signal reconnaissance

    Författare :Per Hyberg; Björn Ottersten; Alex Gershman; KTH; []
    Nyckelord :ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Signalbehandling; Array mapping; array interpolation; Signalbehandling; Signal processing; Signalbehandling;

    Sammanfattning : To counter radio signal reconnaissance, an efficient way of covert communication is to use subsecond duration burst transmissions in the congested HF band. Against this background, the present thesis treats fast direction finding (DF) using antenna arrays with known response only in a few calibration directions. LÄS MER

  5. 5. On the analysis of soft surfaces, frequency selective surfaces and con­formal antennas

    Författare :Silvia Raffaelli; Chalmers University of Technology; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; array; microstrip; antenna; dual-frequency; corrugated surface; multi-layer structure; periodic; horn; finite difference time domain; method of moments; spectral domain analysis; infinite;

    Sammanfattning : .... LÄS MER