I recently worked on a PA0FRI Active Antenna design with fast BFR93A / BFR106 / BFR193 transistors.
Design
3D render:
Schematic:
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[pdf]
Simulation Results
With BFR193 transistors:
With a more faithful simulation and harder biasing, we were able to improve the OIP3 figure!
Final biasing values?
Updates
March 2026: The design worked right away! Current consumption is ~24mA at 10V voltage input (0.7V is dropped across the polarity protection diode we have in there). This matches the simulations pretty well!
With and without the PA0FRI Active Antenna 2026:
We will check its on-air performance soon!