Sökning: "power amplifier"

Visar resultat 41 - 45 av 162 avhandlingar innehållade orden power amplifier.

1. 41. Modeling and Compensation of Nonlinear Distortion in Multi-Antenna RF Transmitters

   Författare :Katharina Hausmair; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; multi-antenna transmitter; behavioral modeling; over-the-air characterization; digital predistortion; antenna crosstalk; linearization; power amplifier;

   Sammanfattning : Multi-antenna systems are utilized as a way to increase spectral efficiency in wireless communications. In a transmitter, the use of several parallel transmit paths and antennas increases system complexity and cost. Cost-efficient solutions, which employ active antenna arrays and avoid expensive isolators, are therefore preferred. LÄS MER

3. 42. Modeling Approaches for Active Antenna Transmitters

   Författare :Parastoo Taghikhani; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; thermal model.; MIMO; power amplifier; Active antenna transmitter; hybrid beamforming; electrothermal; active subarray antenna; nonlinear distortion;

   Sammanfattning : The rapid growth of data traffic in mobile communications has attracted interest to Multiple-Input-Multiple-Output (MIMO) communication systems at millimeter-wave (mmWave) frequencies. MIMO systems exploit active antenna arrays transmitter configurations to obtain higher energy efficiency and beamforming flexibility. LÄS MER

4. 43. Characterization and Compensation of Hardware Impairments in Transmitters for Wireless Communications

   Författare :Zain Ahmed Khan; Peter Händel; Magnus Isaksson; Mikko Valkama; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Power amplifier; RF transmitters; SISO; MIMO; crosstalk; Volterra series; Volterra kernels; behavioral modeling; DPD; Ramanujan sums; multitone signals; I Q Imbalance; non-linearity; memory polynomial; density estimation; hardware impairments; Electrical Engineering; Elektro- och systemteknik;

   Sammanfattning : Increasing demands for data rate, energy efficiency and reliability in wireless communications have resulted in the introduction of radio frequency (RF) multiple input multiple output (MIMO) transmitters. However, MIMO transmitters suffer from additional crosstalk impairments along with the power amplifier (PA) and I/Q imbalance distortions observed in single input single output (SISO) transmitters. LÄS MER

5. 44. Microwave FET Modeling and Applications

   Författare :Christian Fager; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; MESFET; uncertainty; model; FMCW; statistical; HEMT; small-signal; extraction; distortion; intermodulation; CMOS; LDMOS; power amplifier; estimation; FET; large-signal; radar; AM noise;

   Sammanfattning : This thesis deals with three distinct topics within the areas of modeling, analysis and circuit design with microwave field effect transistors (FETs). First, the extraction of FET small-signal model parameters is addressed. LÄS MER

7. 45. InAs Nanowire Devices and Circuits

   Författare :Kristofer Jansson; Institutionen för elektro- och informationsteknik; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Modelling; Circuit; Simulation; Ballistic; Capacitor; Transistor; RF; Band structure; III-V semiconductor; InAs; MOSFET; Metal-oxide-semiconductor field-effect transistor; Nanowire; Amplifier;

   Sammanfattning : Since the introduction of the transistor and the integrated circuit, the semiconductor industry has developed at a remarkable pace. By continuously fabricating smaller and faster transistors, it has been possible to maintain an exponential increase in performance, a phenomenon famously described by Moore’s Law. LÄS MER