Search for dissertations about: "Fundamental bounds"

Showing result 1 - 5 of 48 swedish dissertations containing the words Fundamental bounds.

  1. 1. Fundamental Bounds on Performance of Periodic Electromagnetic Radiators and Scatterers

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

    Abstract : 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. READ MORE

  2. 2. Optimization and Physical Bounds for Passive and Non-passive Systems

    Author : Yevhen Ivanenko; Sven Nordebo; Börje Nilsson; Mats Gustafsson; Mariana Dalarsson; Aaron Welters; Linnéuniversitetet; []
    Keywords : ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Convex optimization; physical bounds; Herglotz functions; quasi-Herglotz functions; passive systems; non-passive systems; approximation; absorption in lossy media; Waves and Signals; Vågor och signaler;

    Abstract : Physical bounds in electromagnetic field theory have been of interest for more than a decade. Considering electromagnetic structures from the system theory perspective, as systems satisfying linearity, time-invariance, causality and passivity, it is possible to characterize their transfer functions via Herglotz functions. READ MORE

  3. 3. Computational Tools for Antenna Analysis and Design

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

    Abstract : 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. READ MORE

  4. 4. Limited Feedback Information in Wireless Communications : Transmission Schemes and Performance Bounds

    Author : Thanh Tùng Kim; Mikael Skoglund; Hesham El Gamal; KTH; []
    Keywords : ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Diversity-multiplexing tradeoff; Large deviation analysis; Limited feedback; MIMO channels; Relay channels; Telecommunication; Telekommunikation;

    Abstract : This thesis studies some fundamental aspects of wireless systems with partial channel state information at the transmitter (CSIT), with a special emphasis on the high signal-to-noise ratio (SNR) regime. The first contribution is a study on multi-layer variable-rate communication systems with quantized feedback, where the expected rate is chosen as the performance measure. READ MORE

  5. 5. Identification of Stochastic Continuous-time Systems : Algorithms, Irregular Sampling and Cramér-Rao Bounds

    Author : Erik Larsson; Torsten Söderström; Bo Wahlberg; Uppsala universitet; []

    Abstract : The problem of identifying continuous-time systems is of fundamental interest in various areas, such as astrophysics, economics, control and signal processing. The most obvious reason for working with continuous-time models is that most physical systems are inherently continuous in time. READ MORE