LDMOS RF Amplifier Controller (part of Forte 600 Amplifier Project)

LDMOS Amplifier Controller V2 (in progress).

Amplifier controller V1 schematics

This is a first revision of my solid state amplifier controller. I am not fully satisfied with how it turned out but it is functional. Best part of this controller turned out to be the software. In contrast to many other amplifiers, the Forte 600 uses 32 bit microcontroller with real time operating system. This allows for a more advanced monitoring systems, precise timing controls and flexible interfacing with different transceivers. Hardware required some modifications, those are included in the below schematics. One thing that proven to be especially important was the decoupling for the ADC, original filtering proven to be insufficient resulting in triggering of built in protection. If you want to build your own controller I would advise you to put extra effort in filtering of the line that samples the drain voltage of LDMOS, spikes on that line can eaisly be interpreted as an overvoltage condition.

For theory of operation, see chapter 5 of my thesis.