RF Feedback Amplifier

I’ve written a Jupyter Notebook in Python that mirrors the functionality of Wes Hayward’s Feedback Amplifier calculator fba08.exe that is provided with his book Experimental Methods in RF Design - and following the math in his earlier book Introduction to Radio Frequency Design (- both truly excellent books!).

See: Feedback Amplifier

(the repo code runs in a Docker container and the content is then viewed via a web browser, see README).

The code is a work-in-progress and needs some cleanup, but the resulting calculations match those in Wes’s fba08.exe utility.

Here is a screenshot of it running:

and a screenshot from Wes’s fba08.exe with the same parameters:

This was an interesting learning journey, focusing on Y and Cascading ABCD Matrix Parameters and associated math. These were the matrix representations of the:

• base spreading resistance,
• degenerating complex emitter impedance,
• hybrid-pi model of the transistor (and complex $\beta$),
• complex impedance of the feedback network,
• output impedance matching transformer,
• and how the source and load impedances affect the output and input impedances of the amplifier.