Sökning: "modulation techniques"
Visar resultat 11 - 15 av 231 avhandlingar innehållade orden modulation techniques.
11. Development of optimized radiation therapy using external electron and photon beams
Sammanfattning : The development of new intensity modulated radiation therapy (IMRT) techniques and treatment optimization tools makes it desirable to further improve modulation methods by using scanned photon and electron beams. It is shown that the narrowest possible photon beams have the potential to improve the flexibility in dose delivery, speed up the dose delivery and improve the treatment outcome. LÄS MER
12. Electric machine control for energy efficient electric drive systems
Sammanfattning : Pure electric vehicles and hybrid electric vehicles are of increasing interest in the automotive industry, much due to challenges such as emission level legislations and the environmental impact of the transportation sector. When continuously striving for better performing and more energy efficient electric powertrains, with high drivability and redundancy, there is an ever increasing need for further research and development in the areas of controls, design and system level optimization. LÄS MER
13. High efficiency power amplifiers for wireless communications
Sammanfattning : This thesis presents state-of-the-art high efficiencyharmonically-tuned power amplifiers (PAs) and investigates thecharacteristics and potentials of such amplifiers in two of the mostpromising efficiency enhancement techniques, dynamic supply and load modulation.In this work, a 10 W LDMOS harmonically-tuned PA with 80% power-added-efficiency (PAE) isrealized at 1 GHz. LÄS MER
14. Low Noise Oscillator in ADPLL toward Direct-to-RF All-digital Polar Transmitter
Sammanfattning : In recent years all-digital or digitally-intensive RF transmitters (TX) have attracted great attention in both literature and industry. The motivation is to implement RF circuits in a manner suiting advanced nanometer CMOS processes. To achieve that, information is encoded in the time-domain rather than voltage amplitude. LÄS MER
15. Electric Machine Control for Energy Efficient Electric Drive Systems
Sammanfattning : Over the past decade, electric vehicles has increasingly become an area of attention for both academia and industry, much due to challenges such as emissions legislation and the environmental impact of the transportation sector. The absence of the broadband noise from the internal combustion engine brings new acoustic challenges for electric propulsion applications. LÄS MER
