Sökning: "pulse"

Visar resultat 6 - 10 av 878 avhandlingar innehållade ordet pulse.

1. 6. Control and Analysis of Pulse-Modulated Systems

   Författare :Stefan Almér; Ulf Jönsson; Gilead Tadmor; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Pulse-width modulation; Periodic systems; Stability analysis; Harmonic analysis; Lyapunov methods; Dynamic phasors; Harmonic transfer function; Switched mode power converters; Sampled data modeling; H-infinity synthesis; Optimization; systems theory; Optimeringslära; systemteori;

   Sammanfattning : The thesis consists of an introduction and four appended papers. In the introduction we give an overview of pulse-modulated systems and provide a few examples of such systems. Furthermore, we introduce the so-called dynamic phasor model which is used as a basis for analysis in two of the appended papers. LÄS MER

3. 7. Second-generation High-Order Harmonic Sources — From CPA to OPCPA

   Författare :Piotr Rudawski; Atomfysik; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Optical parametric chirped pulse amplification; Fysicumarkivet A:2014:Rudawski; Chirped pulse amplification; High-order harmonic generation; Attosecond pulse;

   Sammanfattning : This thesis presents two sources of extreme ultraviolet (XUV) radiation based on high-order harmonic generation (HHG) in gases. The sources were developed for experiments requiring high-flux harmonic beams or HHG pulses at high-repetition rate. These were used experimentally to image nano-scale objects. LÄS MER

4. 8. Sources and Diagnostics for Attosecond Science

   Författare :Miguel Miranda; Atomfysik; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Pulse Compression; High-order Harmonic Generation; Ultrafast; Ultrashort; Attosecond; Femtosecond; Pulse Characterization; Fysicumarkivet A:2012:Miranda;

   Sammanfattning : Ultrafast science refers to physical events that happen on the femtosecond (1 fs=10^-15 s) and attosecond (1 as=10^-18 s) timescales. Generation of attosecond pulses is usually achieved by interacting high-intensity femtosecond pulses with matter (typically gases), in a process called high-order harmonic generation (HHG). LÄS MER

5. 9. Pulse-Width Modulated RF Transmitters

   Författare :Muhammad Fahim Ul Haque; Ted Johansson; Dake Liu; Qamar Ul Wahab; Franz Dielacher; Linköpings universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES;

   Sammanfattning : The market for wireless portable devices has grown signicantly over the recent years.Wireless devices with ever-increased functionality require high rate data transmissionand reduced costs. LÄS MER

7. 10. Device Technology Based on High Temperature Superconductors and Microwave Breakdown in Gases

   Författare :Martin Löfgren; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; distortion; penetration depth; surface resistance; transmit-receive switch; coupled-grain model; high-power; microwave; pulse; surface impedance; breakdown; propagation; modulator; air; superconductor; transmission line; resonator; coplanar waveguide; plasma;

   Sammanfattning : This thesis deals with two separate fields of microwave technology. The first section treats microwave characterization and applications of high temperature superconducting (HTS) thin films, while the second section treats microwave breakdown in transmit-receive (TR) switches and in air. Within the first section, four main topics are adressed. LÄS MER