Design of an 800W GaN Power Amplifier Stage for Pulsed L Band Applications Using Simulated Load Pull

Abstract:

What happens when you are asked to put everything else to one side and quickly develop a PA stage? Oh, and it is 800W…, and it is a new device that has just come out of development…, but we do have a model. This webinar is a real account of what happens and how just such an amplifier was created using the nonlinear simulation capabilities of MWO, and the large signal model of the CGHV14800F from Wolfspeed. Dealing with such high peak power levels, even though they are pulsed, requires careful consideration for all of the components used and a robust design and test strategy to ensure that you not only have a working solution, but that you haven’t done (too much) damage on the way.

Issues covered:

• Differences between GaN and LDMOS or Si Bipolar solutions.
• Stability and biasing: class trade-offs and implications.
• Amplifier topology
• Using measured matching circuits
• Hunting down component resonances
• Device dissipation simulation
• Test method, water cooled stage, high power load, measuring gate and drain current
• Test results and tuning

The manufactured stage will be compared with the simulated performance.

The webinar should be of interest to those currently involved in the design of high power amplifiers, students intending to undertake such projects, and system and project engineers wishing to get a better understanding of the processes involved and the best tools available for crafting RF and Microwave amplifiers.

Presenter Bio:

Dominic FitzPatrick has been involved with the design of solid state RF & Microwave amplifiers for over 30 years. He holds a B.Sc. and M.Sc. (Solid State Microwave Physics) from the University of Portsmouth, England, and a PhD from Cardiff University. He has been the Technical Director of two UK companies designing and manufacturing SSPAs. Since 2010 he has run Powerful Microwave, a consultancy specialising in the design and manufacture of solid state microwave amplifiers. He is a co-author of “The Handbook of RF and Microwave Power Amplifiers”, Cambridge University Press.