Sökning: "adaptive antenna arrays"

Visar resultat 1 - 5 av 11 avhandlingar innehållade orden adaptive antenna arrays.

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

   Författare :Shuai Zhang; Sailing He; Raj Mittra; KTH; []
   Nyckelord :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

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

   Författare :Mattias Wennström; Michael A. Jensen; Uppsala universitet; []
   Nyckelord :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;

   Sammanfattning : 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). LÄS MER

4. 3. Computational Tools for Antenna Analysis and Design

   Författare :Doruk Tayli; Teoretisk elektroteknik; []
   Nyckelord :Antenna theory; Fundamental bounds; method of moments MoM ; Characteristic modes; macro basis functions MBFs ; adaptive cross approximation ACA ; endfire arrays;

   Sammanfattning : Many engineers and scientists prevalently use computational tools in electromagnetics, which is also the predominant case for antennas. The ever-increasing number of applications and technologies that employ antennas create a constant demand to improve and extend existing tools and develop new ones. LÄS MER

5. 4. Direction finding, beamforming and mutual coupling in base station antenna arrays

   Författare :Staffan Lundgren; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; mutual coupling; adaptive arrays; direction finding; base station antennas; mobile communications; phase-only nulling; beamforming; dual polarization; butler matrix;

   Sammanfattning : .... LÄS MER

7. 5. Analysis and Design of Base Station Antennas for Mobile Communications

   Författare :Björn Lindmark; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; polarization diversity; dual polarization; adaptive antennas; moment method; genetic algorithm; antenna arrays; radio propagation; channel sounding; aperture coupled patch;

   Sammanfattning : The thesis deals with base station antennas and the environment they work in. Polarization diversity, dual band operation, and adaptive antenna systems are discussed with emphasis on how antennas for these applications should be designed. We compare the polarization diversity performance of different types of dual polarized antenna elements. LÄS MER