Sökning: "power amplifier"

Visar resultat 31 - 35 av 162 avhandlingar innehållade orden power amplifier.

1. 31. Frequency Reconfigurable and Linear Power Amplifiers Based on Doherty and Varactor Load Modulation Techniques

   Författare :William Hallberg; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; gallium nitride GaN ; wideband; Class-J; linear; microwave; radio frequency RF ; Doherty; broadband; AM AM; silicon carbide SiC ; bandwidth; power amplifier PA ; AM PM; varactor; dynamic load modulation DLM ; fifth generation mobile networks 5G ; energy efficiency;

   Sammanfattning : In future mobile communication networks, there will be a shift towards higher carrier frequencies and highly integrated multiple antenna systems. The system performance will largely depend on the available RF hardware. As such, RF power amplifiers (PAs) with improved efficiency, linearity, and bandwidth are needed. LÄS MER

3. 32. Behavioral modeling of wireless transmitters for distortion mitigation

   Författare :Ali Soltani Tehrani; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; nonlinear models; wireless communications.; computational complexity; I Q imbalance; digital predistortion; Volterra series; transmitter; power amplifier; Behavioral modeling;

   Sammanfattning : As the demand for high speed and reliable wireless communication increases, theimportance of having a linear transmitter has enhanced. Distortions created by thetransmitter, such as power amplifier nonlinearity and I/Q imbalance, diminish thefidelity and limit the performance of wireless systems, if left undealt with. LÄS MER

4. 33. Reliable and Efficient Microwave Circuits for Space Applications

   Författare :Andreas Ådahl; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; ZBD; PA; Class E; Zero Bias Diode; LDMOS; Mixer; MMIC; Satellite; Balun; Inverse class F; Novel; Multiplier; mHEMT; Power amplifier; Converter;

   Sammanfattning : In this thesis, reliable and efficient microwave circuits used in space applications, e.g. satellite transponder systems, are discussed. The main focus is on mixers, multipliers and power amplifiers. LÄS MER

5. 34. Linearization of High Efficiency Transmitters for Wireless Communications

   Författare :Haiying Cao; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; dynamic load modulation; Behavioral model; digital predistortion; I Q imbalance; Volterra series; efficiency; power amplifier; transmitter;

   Sammanfattning : In recent years, reducing energy consumption in wirelesscommunication systems has gained prominence. In order to achieve this energy saving, high power efficiency is necessary for the wireless transmitters used. LÄS MER

7. 35. On Massive MIMO Base Stations with Low-End Hardware

   Författare :Christopher Mollén; Erik G. Larsson; Thomas Eriksson; Josef Nossek; Linköpings universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; massive MIMO; hardware; ADC; power amplifier; out-of-band radiation; peak-to-average ratio;

   Sammanfattning : Massive MIMO (Multiple-Input Multiple-Output) base stations have proven, both in theory and in practice, to possess many of the qualities that future wireless communication systems will require.  They can provide equally high data rates throughout their coverage area and can concurrently serve multiple low-end handsets without requiring wider spectrum, denser base station deployment or significantly more power than current base stations. LÄS MER