Sökning: "wideband signals"

Visar resultat 1 - 5 av 43 avhandlingar innehållade orden wideband signals.

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

   Författare :David Gustafsson; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Doherty; gallium nitride; GaN; power amplifier; MMIC; microwave; Broadband amplifiers; high efficiency; wideband;

   Sammanfattning : 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. LÄS MER

3. 2. Efficient and Wideband Power Amplifiers for Wireless Communications

   Författare :Paul Saad; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; multi-band; Doherty power amplifier; high efficiency; Branch-line coupler; wideband.; power amplifier; GaN-HEMT;

   Sammanfattning : The rapid evolution of wireless communication systems and the developmentof new standards require that wireless transmitters process several types ofstandards across multiple bands. Power amplifiers (PAs) are key componentsin wireless transmitters because they have a big impact on the overall systemperformance in terms of their bandwidth, efficiency, and linearity. LÄS MER

4. 3. Compact and Efficient Millimetre-Wave Circuits for Wideband Applications

   Författare :Lars Ohlsson; Institutionen för elektro- och informationsteknik; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; resonant-tunnelling diode; millimetre-wave spectrum; integrated transmitter; energy-efficiency; compact circuit; dielectric resonator antenna; transistor; wavelet generator; wideband.;

   Sammanfattning : Radio systems, along with the ever increasing processing power provided by computer technology, have altered many aspects of our society over the last century. Various gadgets and integrated electronics are found everywhere nowadays; many of these were science-fiction only a few decades ago. LÄS MER

5. 4. Wideband CMOS Data Converters for Linear and Efficient mmWave Transmitters

   Författare :Victor Åberg; Chalmers tekniska högskola; []
   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; CMOS; Efficient; MIMO; Predistortion; mmWave; RF-DAC; Wideband; SAR ADC; Linear; Linearization;

   Sammanfattning : With continuously increasing demands for wireless connectivity, higher carrier frequencies and wider bandwidths are explored. To overcome a limited transmit power at these higher carrier frequencies, multiple input multiple output (MIMO) systems, with a large number of transmitters and antennas, are used to direct the transmitted power towards the user. LÄS MER

7. 5. Nonlinear Characterization of Wideband Microwave Devices and Dispersive Effects in GaN HEMTs

   Författare :Sebastian Gustafsson; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; large-signal; dispersive effects; electron trapping; thermal coupling; HEMT; GaN; microwave; wideband;

   Sammanfattning : Measurements play a key role in the development of microwave hardware as they allow engineers to test and verify the RF performance on a system, circuit, and component level. Since modern cellular standards employ complex modulation formats with wider signal bandwidths to cope with the growing demand of higher datarates, nonlinear characterization using wideband stimuli is becoming increasingly important. LÄS MER