Sökning: "active antennas"

Visar resultat 1 - 5 av 27 avhandlingar innehållade orden active antennas.

  1. 1. Wideband Active and Passive Antenna Solutions for Handheld Terminals

    Detta är en avhandling från Uppsala : Acta Universitatis Upsaliensis

    Författare :Peter Lindberg; Uppsala universitet.; [2007]
    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

  2. 2. Integrated Antennas Monolithic and Hybrid Approaches

    Detta är en avhandling från Uppsala : Acta Universitatis Upsaliensis

    Författare :Erik Öjefors; Uppsala universitet.; [2006]
    Nyckelord :Electronics; antenna travelling wave arrays; antenna phased arrays; phase shifters; micromachining; silicon; monolithic microwave integrated circuits; dipole antennas; loop antennas; slot antennas; Elektronik;

    Sammanfattning : This thesis considers integration of antennas and active electronics manufactured on the same substrate. The main topic is on-chip antennas for commercial silicon processes, but hybrid integration using printed circuit board technology is also addressed. LÄS MER

  3. 3. Miniaturized Hard Waveguides in Multifunction Array Antennas

    Detta är en avhandling från Chalmers University of Technology

    Författare :Malcolm Ng Mou Kehn; Chalmers tekniska högskola.; Chalmers University of Technology.; [2005]
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Elektroteknik; elektronik och fotonik; Electrical engineering; electronics and photonics; multifunction antennas; interlaced arrays; aperture reuse; array antennas; miniaturized waveguides; soft and hard surfaces; periodic structures; Floquet theorem; spectral domain technique; multilayer structures; method of moments; focal plane array; reflector antennas;

    Sammanfattning : Recent advances in technologies of wireless communications systems have led to an increasing desire for several antennas performing diverse functions at different frequencies to be integrated into a common radiating aperture. This gives rise to the so-called multifunction antenna, which affords the saving of scarce premium real estate and can alleviate problems arising from excessive antenna protrusions in aspects such as aerodynamics, aesthetics, and stealth capability in military applications. LÄS MER

  4. 4. Integrated Antenna Solutions for Wireless Sensor and Millimeter-Wave Systems

    Detta är en avhandling från Uppsala : Acta Universitatis Upsaliensis

    Författare :Shi Cheng; Uppsala universitet.; [2009]
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; harmonic radar HR ; liquid alloy; millimeter-wave; micromachining; phase shifters; planar inverted cone antennas PICA ; printed circuit boards PCB ; quasi-Yagi antennas; radio frequency microelectromechanical system RF MEMS ; stretchable antennas; substrate integrate waveguides SIW ; T-matched dipole antennas; tapered slot antennas; traveling wave array antennas; ultrawideband UWB ; wireless sensor networks.; TECHNOLOGY Electrical engineering; electronics and photonics Electrical engineering; TEKNIKVETENSKAP Elektroteknik; elektronik och fotonik Elektroteknik; Elektronik; Electronics;

    Sammanfattning : This thesis presents various integrated antenna solutions for different types of systems and applications, e.g. wireless sensors, broadband handsets, advanced base stations, MEMS-based reconfigurable front-ends, automotive anti-collision radars, and large area electronics. LÄS MER

  5. 5. Gap Waveguide Technology for Millimeter Wave Applications and Integration with Antennas

    Detta är en avhandling från Chalmers University of Technology

    Författare :Elena Pucci; Chalmers tekniska högskola.; Chalmers University of Technology.; [2013]
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Gap Waveguides; Artificial Magnetic Conductors; Millimeter Waves; Micromachining; Losses; Waveguide Resonators; Packaging of Microwave Components; Microstrip Lines; Array Antennas.;

    Sammanfattning : The increasing advance of short range wireless communications requiring high data rates and the lack of available spectrum have driven researchers and industry to move towards higher frequencies, in particular to the millimeter wave range. The opening of this wide portion of free spectrum has risen a large interest in developing mm-wave communication systems for commercial applications. LÄS MER