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Visar resultat 11 - 15 av 294 avhandlingar som matchar ovanstående sökkriterier.

  1. 11. Monocrystalline-Silicon Based RF MEMS Devices

    Författare :Mikael Sterner; Joachim Oberhammer; Roberto Sorrentino; KTH; []
    Nyckelord :RF MEMS; radio frequency; microelectromechanical system; microsystem technology; monocrystalline silicon; switch; tuneable capacitor; high-impedace surface; phase shifter; rectangular waveguide; transmission line;

    Sammanfattning : This thesis presents novel radio-frequency microelectromechanical (RF MEMS) devices, for microwave and millimeter wave applications, designed for process robustness and operational reliability using monocrystalline silicon as structural material. Two families of RF MEMS devices are proposed. LÄS MER

  3. 12. Electromagnetic noise generated in the electrified railway propulsion system

    Författare :Kelin Jia; Rajeev Thottappillil; Hans Bängtsson; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Electromagnetic compatibility; railway; propulsion system; shielded cable; transmission line; Electrical engineering; Elektroteknik; Telecommunication; Telekommunikation; SRA - Transport; SRA - Transport;

    Sammanfattning : The electromagnetic compatibility (EMC) problem in the railway propulsion system is a significant safety issue of high concern. The problems can be caused by any part of the propulsion system as well as any combination of the sub systems. Simulation is a fast economical way to understand the system and to predict the EMC performance. LÄS MER

  4. 13. Novel RF MEMS Devices Enabled by Three-Dimensional Micromachining

    Författare :Umer Shah; Joachim Oberhammer; Raafat Mansour; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Microelectromechanical systems; MEMS; Radio frequency microelectromechanical systems; RF MEMS; Micromachined transmission line; Micromachining; Tuneable capacitor; Switched capacitor; Coupled-line coupler; Tuneable directional coupler; Intermodulation distortion; MEMS varactor; Two-tone IIP3 measurement; Passive components and circuits; Reliability; Magnetic materials; NiFe multilayer composite; Permeability; Permittivity; Micromachined inductors;

    Sammanfattning : This thesis presents novel radio frequency microelectromechanical (RF MEMS) circuits based on the three-dimensional (3-D) micromachined coplanar transmission lines whose geometry is re-configured by integrated microelectromechanical actuators. Two types of novel RF MEMS devices are proposed. LÄS MER

  5. 14. Multiconductor transmission lines wideband modeling : A delay-rational Green’s-function-based method

    Författare :Maria De Lauretis; Jonas Ekman; Giulio Antonini; Wil Schilders; Luleå tekniska universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Industriell elektronik; Industrial Electronics;

    Sammanfattning : The performance of variable-frequency drives (VFDs) commonly used in energy production plants can be severely affected by electromagnetic (EM) noise in the form of conducted disturbances.A VFD is composed of an inverter, a motor, and a connecting power cable. LÄS MER

  7. 15. Tunable superconducting transmissionline resonator for qubit coupling

    Författare :Martin Sandberg; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; fast tuning; superconductivity; transmission line; SCB; Josephson inductance.; Frequency tunable resonator; SQUID; CPW; aluminium;

    Sammanfattning : In this licentiate thesis design, fabrication, and measurements of tunable superconducting microwave transmission line resonators are described. The resonators are of quarter wavelength type were the tuning is achieved by changing one of the boundary conditions of the resonator through a tunable impedance. LÄS MER