Dates
Jan 13, 2026 – Feb 12, 2026
4 Weeks
Class Days
Tuesdays and Thursdays
There are no classes on January 20 and January 22
Class sessions are held on January 13, 15, 27, 29, and February 3, 5, 10, and 12
Meeting Times
2:30 PM – 5:30 PM ET
24 Hours | 3-hr lectures twice a week
Course Description
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: Concept, Design, Limitations, and Examples. • Effects of knee voltage, harmonic terminations, and nonlinearities. • GaN pHEMT power amplifiers • Exercise: High efficiency power amplifier design.
Linearization Techniques and Signal Modulations
• Classical Modulation schemes: AM, FM, PM. • Modern Modulation: FSK, PSK, MSK, BPSK, QPSK, p/4-DQPSK, OQPSK, QAM, etc. • 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. • X-parameters. • Linearization techniques: Feed Forward, Predistortion, LINC, Cartesian Feedback, Reflect Forward, Envelope Elimination and Restoration, Cross Cancellation. • Comparison of Linearization Techniques. • Real world design examples, challenges, and solutions.
Power Combining, Packaging, and Reliability
• Multistage amplifiers, inter-stage matching. • Push-pull, Balanced amplifiers, and Traveling Wave Combiners. • Power combining techniques. • Exercise: Design of a power combiner. • Package design. • Thermal management and reliability calculations. • Biasing and transient considerations. • Exercise: calculating required biasing for 20+ year lifetime.
CAD Implementation
• Design using Microwave Office ® tools. • Translating the concepts learned into actual designs, including device selection based on specifications, circuit topology, simulation, and layout. • Simulations of power added efficiency (PAE), linearity (AM-AM and AM-PM), etc. • Design of class AB amplifier, and class-F.
Course Perquisites
Basic knowledge of microwave measurements and transmission line (Smith Chart) theory is assumed.
Target Audience
Designed for U.S. citizens working in the Department of War, Government, or Government-affiliated employees, industry, as well as college students and faculty. Must register with your organizational email, and will be notified of acceptance within one week of the course start date.
This course benefits microwave engineers seeking to design, fabricate, and test power amplifiers operating in the 1–50 GHz frequency range.
Registration
Registration is open!
Ali Darwish
Course Instructor
Ali Darwish, Ph. D., received his Ph.D. degree from Massachusetts Institute of Technology (MIT), Cambridge, MA, in 1996. In 1997, he co-founded Amcom Communications Inc., a leading supplier of high-power microwave amplifiers and integrated circuits. At Amcom Communications, he served as the vice president of product development, where he designed and commercialized several product lines. In May 2003 he joined a US government research lab where he conducted research on wide bandgap materials (GaN), thermal analysis of active devices, and novel MMIC concepts.
Dr. Darwish designed several state-of-the-art monolithic microwave integrated circuits (MMICs), including an X-band low phase noise oscillator, GaN mm-wave power amplifiers, SiGe mm-wave amplifiers, broadband high power amplifiers (in the L-, S-, X-, Ku-, and Ka-band), mixers, digital attenuator, and phase shifters. Dr. Darwish is an associate editor of IEEE Microwave Magazine and an adjunct faculty member with Johns Hopkins University. He is an IEEE Senior Member and an active member of MTT-S. His areas of expertise include novel techniques in millimeter-wave MMICs, in GaN and GaAs, sub-terahertz communications, and reliability and thermal characterization of MMICs. He has published over 100 journal and conference papers.