Sökning: "near-field antennas"

Visar resultat 1 - 5 av 12 avhandlingar innehållade orden near-field antennas.

  1. 1. Optimal Near-field Antenna Apertures in Lossy Media

    Författare :Aidin Razavi; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; optimal near-field aperture; near-field focusing; near-field antennas; near-field power transfer; array signal processing.; maximum penetration;

    Sammanfattning : Antennas are traditionally designed for far-field applications such as wireless communications, radar, etc., where the antenna systems interact with other systems and objects which are located in the far-field zone of the antennas. LÄS MER

  3. 2. Characterization and Design Requirements for Antennas in the Near-field and the Random-LOS Propagation Environment

    Författare :Aidin Razavi; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; polarization-MIMO; Random-LOS; OTA; Antenna measurements; near-field antennas; antenna characterization; MIMO; near-field focusing;

    Sammanfattning : The choice of antenna for a particular application depends on the requirements imposed by that application. These can be, the application's field region (i.e., near-field or far-field), polarization, radiation pattern, radiation efficiency, system throughput, etc. LÄS MER

  4. 3. Photonic terahertz-wave generation, radiation and quasioptical integration

    Författare :Biddut Kumar Banik; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; semiconductor device modelling; semiconductor diodes; III-V semiconductors; Catadioptric lens; imaging; dipole antennas; slot antennas; lens antennas; semiconductor heterojunctions; dielectric loaded antennas; optical mixers; photomixers; near-field imaging; computer aided engineering; indium compounds; millimetre wave imaging; near-field optics; submillimeter wave generation; photodiodes; terahertz sources; millimetre wave generation; submillimetre wave integrated circuits; microwave imaging; uni-travelling-carrier photodiodes;

    Sammanfattning : This thesis deals with the uni-travelling-carrier photodiode (UTC-PD) based photonic generation of terahertz waves, antenna designs for the terahertz radiation and a novelcatadioptric lens for quasioptical integration.The ongoing and accomplished research work on the UTC-PD, its limitations and optimisation scopes for attaining higher bandwidth and higher output power have been discussed. LÄS MER

  5. 4. On signal processing and electromagnetic modelling : applications in antennas and transmission lines

    Författare :Jonas Lundbäck; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Vector sensors; Statistical signal processing; Antennas; Directional Coupler; Tranmission lines; Partial discharge;

    Sammanfattning : This doctoral thesis is comprised of five parts. The first three parts concern signal processing and electromagnetic modelling of multiport antennas. The last two parts concern signal processing and transmission line theory applied to wave splitting on transmission lines. LÄS MER

  7. 5. Over-the-Air Performance Estimation of Wireless Device Antennas

    Författare :Sathyaveer Prasad; Peter Händel; Gert Frölund Pedersen; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

    Sammanfattning : This thesis work presents studies on the available measurement methods for estimating the over-the-air (OTA) performance of wireless device antennas. This thesis is divided into two parts. LÄS MER