Advanced search

Showing result 1 - 5 of 58 swedish dissertations matching the above criteria.

  2. 1. Active and Passive Unequally Spaced Reflect-Arrays and Elements of RF Integration Techniques

    Author : Dhanesh G. Kurup; Anders Rydberg; Mohamed Himdi; Peter S Hall; Uppsala universitet; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Electrical engineering; Active Antenna; Reflect-arrays; NRD guide; RF integration; Elektroteknik; elektronik och fotonik; Electrical engineering; electronics and photonics; Elektroteknik; elektronik och fotonik;

    Abstract : Using an array synthesis tool based on a modified differential evolution algorithm, it is shown that the position-phase synthesis exhibits improved pattern characteristics compared to both the phase only and position only synthesis of uniform amplitude antenna arrays. The design of an unequally spaced planar reflect-array and an active power combining reflect-array are presented. READ MORE

  4. 2. Modeling and Compensation of Nonlinear Distortion in Multi-Antenna RF Transmitters

    Author : Katharina Hausmair; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; multi-antenna transmitter; behavioral modeling; over-the-air characterization; digital predistortion; antenna crosstalk; linearization; power amplifier;

    Abstract : Multi-antenna systems are utilized as a way to increase spectral efficiency in wireless communications. In a transmitter, the use of several parallel transmit paths and antennas increases system complexity and cost. Cost-efficient solutions, which employ active antenna arrays and avoid expensive isolators, are therefore preferred. READ MORE

  5. 3. Microsystem technology for microwave applications at frequencies above 100 GHz

    Author : Sofia Rahiminejad; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Transitions; GHz; High frequency; RF; MEMS; Gap waveguides; Waveguide;

    Abstract : The rapid development of wireless technology today shows an increasing need forelectromagnetic components operating at even higher frequencies. Higher frequencies offer wider bandwidth, higher spatial resolution and are needed for technologies such as automotive car radars, wireless media communication and body scanners. READ MORE

  6. 4. RF Energy Harvesting for Zero-Energy Devices and Reconfigurable Intelligent Surfaces

    Author : Morteza Tavana; Emil Björnson; Jens Zander; George Alexandropoulos; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Electronic waste; energy harvesting; Internet of Things; optimization; phased array; reconfigurable intelligent surfaces; stochastic geometry; wireless power transfer; wireless sensor networks; zero-energy devices.; Elektronikskrot; energiutvinning; sakernas internet; optimering; fasstyrda antenner; omkonfigurerbara intelligenta ytor; stokastisk geometri; trådlös kraftöverföring; trådlösa sensornätverk; nollenergienheter.; Informations- och kommunikationsteknik; Information and Communication Technology;

    Abstract : The growth of Internet of Things (IoT) networks has made battery replacement in IoT devices increasingly challenging. This issue is particularly pronounced in scenarios with a large number of IoT devices, in locations where IoT devices are difficult to access, or when frequent replacement is necessary. READ MORE

  7. 5. Phased-Array-Fed Reflector Antenna Systems for Radio Astronomy and Earth Observations

    Author : Oleg Iupikov; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

    Abstract : Dense Phased Array Feeds (PAFs) for reflector antennas have numerous advantages over traditional cluster feeds of horns in a one-horn-per-beam configuration, especially in RF-imaging applications which require multiple simultaneously formed and closely overlapped beams. However, the accurate analysis and design of such PAF systems represents a challenging problem, both from an EM-modeling and beamforming optimization point of view. READ MORE