Power amplifier Fundamentals
• Device technologies: GaAs, LDMOS, GaN, Si, SiGe • Small signal model generation, transistor speed (ft, and fmax) calculation. • Power Amplifier Stability: even mode, odd mode. • Optimum power load estimation, calculation, and simulation. • Load-pull characterization of devices. • Device characteristics and non-idealities. • Dependence of transistor parameters on drive level. • Large signal models. • Power Amplifier biasing. • Exercise: GaN pHEMT small signal model generation.
Conventional and High Efficiency Amplifier Design
• Power amplifier classes A, B, AB, C, and D; concepts, designs, and examples. • Waveform engineering for maximum efficiency. • Class E Switching mode power amplifiers: Concept, Design, Limitations, Maximum Frequency, Exercises, and Examples.
• Class F (and F-1) power amplifiers: Concept, Design, Limitations, and Examples. • Comparison of various classes: efficiency, output power, and frequency limitations. • Doherty power amplifiers • Effects of knee voltage, harmonic terminations, and nonlinearities. • GaN pHEMT power amplifiers
Linearization Techniques, Power Combing, Packaging, and Reliability
• Distortions in power amplifiers.
• Harmonic balance and time domain simulations. • Linear/Non-linear Memory effects; electrical and thermal memory effects • Measures of Distortion: Third order intermodulation, ACPR, NPR, M-IMR • Linearization techniques: Feed Forward, Predistortion, LINC, Cartesian Feedback, Envelope Elimination and Restoration, Cross Cancellation. • Comparison of Linearization Techniques • Real world design examples, challenges, and solutions. • Push-pull, Balanced amplifiers, and Traveling Wave Combiners. • Power combining techniques. • Exercise: Design of a power combiner. • Package design • Power Combing, Packaging, and Reliability • Thermal management and reliability calculations. • Biasing and transient considerations. • Exercise: calculating required biasing for 20+ year lifetime.