Sökning: "Microwave oscillator"

Visar resultat 21 - 25 av 35 avhandlingar innehållade orden Microwave oscillator.

  1. 21. Spin momentum transfer effects for spintronic device applications

    Författare :Yan Zhou; Johan Åkerman; Daniel E. Bürgler; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Spin Torque Oscillator; Giant Magnetoresistance; Tunneling Magnetoresistance; Magnetism; Magnetism;

    Sammanfattning : The recent discovery that a spin-polarized current can exert a large torque on a ferromagnet, through direct transfer of spin angular momentum, offers the possibility of electrical current controlled manipulation of magnetic moment in nanoscale magnetic device structures. This so-called spin torque effect holds great promise for two applications, namely, spin torque oscillators (STOs) for wireless communication and radar communication, and spin transfer torque RAM (STT-RAM) for data/information storage. LÄS MER

  3. 22. Recovery and validation of Odin/SMR measurements of mesospheric CO and H2O

    Författare :Francesco Grieco; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; mesosphere; microwave limb sounding; H2O; recovery; CO;

    Sammanfattning : Although life on Earth is concentrated in the troposphere, not only the processes happening here are of interest, since tropospheric processes are not the only ones that have an impact on the climate. Coupling mechanisms between different layers are such that changes in middle atmospheric dynamics and composition have an effect on what happens at lower altitudes. LÄS MER

  4. 23. Millimeter-Wave Impulse Radio

    Författare :Mats Ärlelid; Institutionen för elektro- och informationsteknik; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Compound semiconductor; resonant tunneling diode; ultra wideband; 60 GHz; on-off keying; transmitter; receiver; and super-regenerative oscillator;

    Sammanfattning : This thesis investigates the opportunity of wireless multi-gigabit per second communication at the millimeter-wave (mmW) frequencies around 60 GHz by using impulse radio and nanoelectronics. Today most wireless communication take place in the microwave region, where several different systems and applications are crowding the narrow-band channels. LÄS MER

  5. 24. MMIC-based Low Phase Noise Millimetre-wave Signal Source Design

    Författare :Thi Ngoc Do Thanh; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; millimetre-wave; MMIC; low frequency noise; phase noise; GaN HEMT; signal source; D-band; InP DHBT; deposition method.; SiGe BiCMOS; frequency multiplier; VCO; passivation;

    Sammanfattning : Wireless technology for future communication systems has been continuously evolving to meet society’s increasing demand on network capacity. The millimetre-wave frequency band has a large amount of bandwidth available, which is a key factor in enabling the capability of carrying higher data rates. LÄS MER

  7. 25. Magnetodynamics in Spin Valves and Magnetic Tunnel Junctions with Perpendicular and Tilted Anisotropies

    Författare :Quang Tuan Le; Johan Åkerman; Erik Wahlström; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; perpendicular magnetic anisotropy; tilted-polarizer; spintronics; STT; MTJ; pseudospin-valve; STO; ST-FMR; magnonics; magnetic droplet; droplet nucleation; droplet annihilation; vinkelrät magnetisk anisotropi; lutande polarisator; spinntronik; STT; MTJ; pseudospinnventil; STO; ST-FMR; magnonics; magnetisk droppe; nukleering av droppe; anihilering av droppe.; Physics; Fysik;

    Sammanfattning : Spin-torque transfer (STT) effects have brought spintronics ever closer to practical electronic applications, such as MRAM and active broadband microwave spin-torque oscillator (STO), and have emerged as an increasingly attractive field of research in spin dynamics. Utilizing materials with perpendicular magnetic anisotropy (PMA) in such applications offers several great advantages such as low-current, low-field operation combined with high thermal stability. LÄS MER