Search for dissertations about: "fractional bandwidth"

Showing result 1 - 5 of 8 swedish dissertations containing the words fractional bandwidth.

  1. 1. Gap Waveguide for High Frequency Microwave Application- Validation of Concept, Filter Design & Packaging Aspects

    Author : Ashraf Uz Zaman; [2011]
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; parallel plate stopband; PMC packaging; gap waveguide; fractional bandwidth; Quasi-TEM mode; PMC surface; narrowband filter; high Q resonators;

    Abstract : The overall goal of this thesis is to validate the low loss performance of recently evolved gap waveguide technology and to use this low loss technology for designing critical passive microwave component such as narrow band filter. Also, the exploitation of gap waveguide concept as a packaging solution for densely packed RF circuitry has been presented in this thesis. READ MORE

  2. 2. Extending the Bandwidth of the Doherty Power Amplifier

    Author : David Gustafsson; [2014]
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

    Abstract : The Doherty power amplifier (DPA) is one of the most popular power amplifier (PA) architectures used to obtain high efficiency for modern communication signals having high peak-to-average power ratios. Its often narrowband performance does, however, make it difficult for the DPA to meet the increasing demands of frequency agility in modern wireless communication systems. READ MORE

  3. 3. Theory and Design of Wideband Doherty Power Amplifiers

    Author : David Gustafsson; [2012]
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Doherty; gallium nitride; GaN; power amplifier; MMIC; microwave; Broadband amplifiers; high efficiency; wideband;

    Abstract : The Doherty power amplifier (DPA) is one of the most popular power amplifier architectures for obtaining high average efficiency for modern communication signals with high peak-to-average power ratios (PAPR). However, the DPA suffers from often having narrowband performance which limits its capabilities in wideband and/or multi-standard microwave and radio frequency applications. READ MORE

  4. 4. Towards Ultimate Performance of THz Heterodyne Receivers: SIS Frequency Multiplier and Wideband Passive Components

    Author : Hawal Marouf Rashid; [2016]
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; Wideband passive components; distributed SIS junction; Frequency multiplier; Frequency up-converter; Hybrids; distributed SIS frequency multiplier;

    Abstract : This thesis focuses on the development of advanced components for the future wideband side band separating and / or multipixel receivers for radio-astronomy with ultimate sensitivity.In this thesis, a novel frequency multiplier based on distributed superconducting tunnel (SIS) junctions has been demonstrated for the first time, taking advantage of the extreme inherent nonlinearity of such device. READ MORE

  5. 5. Practical Considerations on Ultrawideband Synthetic Aperture Radar

    University dissertation from Karlskrona : Blekinge Institute of Technology

    Author : Viet Thuy Vu; Blekinge Tekniska Högskola.; [2009]
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

    Abstract : The practical considerations in ultrawideband (UWB) synthetic aperture radar (SAR) data processing in general and UWB SAR imaging in particular are clarified and presented in detail in this thesis. They are imaging algorithm, impulse response function in SAR imaging (IRF-SAR), apodization, RF interference (RFI) and SAR image quality measurement. READ MORE