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Visar resultat 21 - 25 av 38 avhandlingar som matchar ovanstående sökkriterier.

  1. 21. CMOS RF Power Amplifiers for Wireless Communications

    Författare :Jonas Fritzin; Atila Alvandpour; Henrik Sjöland; Linköpings universitet; []
    Nyckelord :TECHNOLOGY; TEKNIKVETENSKAP;

    Sammanfattning : The wireless market has experienced a remarkable development and growth since the introduction of the first modern mobile phone systems, with a steady increase in the number of subscribers, new application areas, and higher data rates. As mobile phones and wireless connectivity have become consumer mass markets, the prime goal of the IC manufacturers is to provide low-cost solutions. LÄS MER

  3. 22. CALLUM Linear Transmitter - Architecture and Circuit Analysis

    Författare :Roland Strandberg; Institutionen för elektro- och informationsteknik; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Telekommunikationsteknik; Telecommunication engineering; loop time delay; modulation negative feedback; spectral emissions; baseband model; CALLUM; Linear transmitter architecture; power amplifier linearization;

    Sammanfattning : This doctoral dissertation presents a study of linear radio transmitters based on the combined analog locked loop universal modulator (CALLUM) approach. Linear architectures such as CALLUM are very attractive for power-efficient operations, since they have no fundamental limitations prohibiting a 100% efficiency for all envelope levels, without sacrificing the potential of a linear transmission. LÄS MER

  4. 23. Integrated millimeter Wave CMOS Power Amplifiers for 5G Systems

    Författare :Christian Elgaard; Integrerade elektroniksystem; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

    Sammanfattning : The anticipated continuation of the last three decades of growth of global demand for high-speed high-coverage mobile data, calls for massive investments in cellular infrastructure, for the ongoing roll out of the fifth generation of mobile systems, but also later for the sixth generation. A key enabler, for the high-speed part, is for the cellular system to move up in frequency and support communication at millimeter-wave (mmW) frequencies (24 – 70 GHz), where available wideband spectrum exist. LÄS MER

  5. 24. Advanced Transmitter Architectures Based on Switch Mode Power Amplifiers

    Författare :MUSTAFA ÖZEN; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; combiner; SMPA; Bandwidth; class-E; outphasing; energy efficiency;

    Sammanfattning : Nowadays the main driving parameters for the research in radio transmitters in wireless infrastructure are energy efficiency, frequency agility, and integration.This thesis presents new solutions at the device waveform-, circuit-, and transmitter level which exploit the inherent high efficiency potential of switch-mode power amplifiers (SMPAs) for realization of energy efficient, wide-band, highly integrated transmitters for wireless communication applications. LÄS MER

  7. 25. Microwave Power Devices and Amplifiers for Radars and Communication Systems

    Författare :Sher Azam; Qamar ul Wahab; Erik Janzén; Georg Boeck; Linköpings universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Semiconductor physics; Halvledarfysik;

    Sammanfattning : SiC MESFETs and GaN HEMTs posses an enormous potential in power amplifiers at microwave frequencies due to their wide bandgap features of high electric field strength, high electron saturation velocity and high operating temperature. The high power density combined with the comparably high impedance attainable by these devices also offers new possibilities for wideband power microwave systems. LÄS MER