Search for dissertations about: "Antenna"

Showing result 21 - 25 of 491 swedish dissertations containing the word Antenna.

  2. 21. On MIMO Systems and Adaptive Arrays for Wireless Communication : Analysis and Practical Aspects

    Author : Mattias Wennström; Michael A. Jensen; Uppsala universitet; []
    Keywords : 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;

    Abstract : 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). READ MORE

  4. 22. NbN and NbTiN Hot Electron Bolometer THz Mixers

    Author : Pourya Khosropanah; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; receiver noise; hot electron bolometer; superconducting detector; spiral antenna; NbTiN; submillimeter mixer; THz mixer; HEB; FTS; NbN; quasioptical receiver; heterodyne receiver; double slot antenna; twin slot antenna; Fourier Transform Spectrometer;

    Abstract : The thesis reports the development of Hot Electron Bolometer (HEB) mixers for radio astronomy heterodyne receivers in THz frequency range. Part of this work is the fabrication of HEB devices, which are based on NbN or NbTiN superconducting thin films (≤5 nm). They are integrated with wideband spiral or double-slot planar antennas. READ MORE

  5. 23. Ultra-wideband Antenna and Radio Front-end Systems

    Author : Magnus Karlsson; Anders Rydberg; Linköpings universitet; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Wireless communication; ultra-wideband; radio communication; UWB bandwidth; antenna parallelism; Electrical engineering; Elektroteknik;

    Abstract : The number of wireless communication applications increase steadily, leading to the competition for currently allocated frequency bands. Pressure on authorities around the world to permit communications in higher and wider frequency ranges to achieve higher wireless capacity than those existed in the past has resulted in several new specifications. READ MORE

  6. 24. Spatial diversity receivers for base station antenna arrays

    Author : Per Pelin; Chalmers tekniska högskola; []
    Keywords : 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;

    Abstract : .... READ MORE

  7. 25. Antenna Designs Aiming at the Next Generation of Wireless Communication

    Author : Sadegh Mansouri Moghaddam; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Phased array antenna; MIMO efficiency; CDF; Millimeter-wave; PoD; OTA; Ultra-Wideband UWB antenna; Tightly-Coupled Dipole Array TCDA .; RIMP; Random-LoS; 5G;

    Abstract : Millimeter-wave (mm-wave) frequencies have drawn large attention, specically for the fifth generation (5G) of wireless communication, due to their capability to provide high data-rates. However, design and characterization of the antenna system in wireless communication will face new challenges when we move up to higher frequency bands. READ MORE