Sökning: "Active antenna array"

Visar resultat 6 - 10 av 27 avhandlingar innehållade orden Active antenna array.

  1. 6. Antenna Designs Aiming at the Next Generation of Wireless Communication

    Författare :Sadegh Mansouri Moghaddam; Chalmers tekniska högskola; []
    Nyckelord :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;

    Sammanfattning : 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. LÄS MER

  3. 7. Miniaturized Hard Waveguides in Multifunction Array Antennas

    Författare :Malcolm Ng Mou Kehn; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; interlaced arrays; Floquet theorem; reflector antennas; focal plane array; multifunction antennas; miniaturized waveguides; multilayer structures; spectral domain technique; periodic structures; aperture reuse; method of moments; soft and hard surfaces; array antennas;

    Sammanfattning : Recent advances in technologies of wireless communications systems have led to an increasing desire for several antennas performing diverse functions at different frequencies to be integrated into a common radiating aperture. This gives rise to the so-called multifunction antenna, which affords the saving of scarce premium real estate and can alleviate problems arising from excessive antenna protrusions in aspects such as aerodynamics, aesthetics, and stealth capability in military applications. LÄS MER

  4. 8. Millimeter-Wave Active Array Antennas Integrating Power Amplifier MMICs through Contactless Interconnects

    Författare :Wan-Chun Liao; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; power amplifier; MMIC; Integrated active antenna; contactless transition;

    Sammanfattning : Next-generation mobile wireless technologies demand higher data capacity than the modern sub-6 GHz technologies can provide. With abundantly available bandwidth, millimeter waves (e.g., Ka/K bands) can offer data rates of around 10 Gbit/s; however, this shift to higher frequency bands also leads to at least 20 dB more free-space path loss. LÄS MER

  5. 9. Active and Passive Unequally Spaced Reflect-Arrays and Elements of RF Integration Techniques

    Författare :Dhanesh G. Kurup; Anders Rydberg; Mohamed Himdi; Peter S Hall; Uppsala universitet; []
    Nyckelord :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;

    Sammanfattning : 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. LÄS MER

  7. 10. Modeling and Compensation of Nonlinear Distortion in Multi-Antenna RF Transmitters

    Författare :Katharina Hausmair; Chalmers tekniska högskola; []
    Nyckelord :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;

    Sammanfattning : 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. LÄS MER