Sökning: "power amplifier PA"
Visar resultat 11 - 15 av 30 avhandlingar innehållade orden power amplifier PA.
11. Frequency Reconfigurable and Linear Power Amplifiers Based on Doherty and Varactor Load Modulation Techniques
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
Sammanfattning : 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. LÄS MER
Sammanfattning : Mathematical models are commonly used in technical applications to describe the behavior of a system. These models can be estimated from data, which is known as system identification. Usually the models are used to calculate the output for a given input, but in this thesis, the estimation of inverse models is investigated. LÄS MER
14. Characterization and Compensation of Hardware Impairments in Transmitters for Wireless Communications
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
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