Sökning: "Antenna performance"

Visar resultat 21 - 25 av 247 avhandlingar innehållade orden Antenna performance.

  1. 21. Multihop Wireless Networks with Advanced Antenna Systems : An Alternative for Rural Communication

    Författare :Marvin Sánchez Garache; Jens Zander; Martha Steenstrup; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Multihop Wirless Networks; Advanced Antenna Systems; Multiple Access Protocols; Spatial TDMA; CSMA CA; link-scheduling; power control; variable transmission rate; Telecommunication; Telekommunikation;

    Sammanfattning : Providing access to telecommunication services in rural areas is of paramount importance for the development of any country. Since the cost is the main inhibiting factor, any technical solution for access in sparsely populated rural areas has to be reliable, efficient, and deployable at low-cost. LÄS MER

  3. 22. Design and Evaluation of Compact Multi-antennas for Efficient MIMO Communications

    Författare :Ruiyuan Tian; Institutionen för elektro- och informationsteknik; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; antenna; propagation channel; MIMO system; wireless communication;

    Sammanfattning : The use of multi-antenna systems with multiple-input multiple-output (MIMO) technology will play a key role in providing high spectrum efficiency for next generation mobile communication systems. This thesis offers valuable insights on the design of compact multi-antennas for efficient MIMO communications. LÄS MER

  4. 23. 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

  5. 24. Fundamental Bounds on Performance of Periodic Electromagnetic Radiators and Scatterers

    Författare :Andrei Ludvig-Osipov; B. Lars G. Jonsson; Christophe Caloz; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Q-factor; bandwidth; antenna arrays; periodic structures; physical bounds; physical limitations; Electrical Engineering; Elektro- och systemteknik;

    Sammanfattning : In this thesis, the optimal bandwidth performance of periodic electromagnetic radiators and scatterers is studied. The main focus is on the development and application of methods to obtain fundamental physical bounds, relating geometrical parameters, frequency bandwidth, efficiency and radiation characteristics of periodic electromagnetic structures. LÄS MER

  7. 25. Ultra Wideband Impulse Radio for Wireless Sensing and Identification

    Författare :Majid Baghaei Nejad; Li-Rong Zheng; Kari Halonen; KTH; []
    Nyckelord :Ubiquitous computing; Impulse Radio; Ultra wideband; RFID; Wireless sensor; WSN; Antenna; System-on-Package; TECHNOLOGY; TEKNIKVETENSKAP;

    Sammanfattning : Ubiquitous computing and Internet-of-Things (IoT) implies an untapped opportunity in the realm of information and communication technology, in which a large number of micro-devices with communication and/or computing capabilities, provides connectivity for anything, by anyone at anytime and anywhere. Especially, these devices can be equipped with sensors and actuators that interact with our living environment. LÄS MER