Hi everyone,
I am trying to understand the structures in an RF amplifier. I am not familier with production processes.
What are these structures which I marked them in the picture below? I thought they are resistance but there are wirebonds on them. What is the blackish material, is it conductive? Also, why there are stub like lines which I marked them with blue and green, is it for adding capacitance.
The thin threads (top right red arrow) connecting parallel lines bring same DC potential, probably ground, or some other value, while chocking high frequencies.
Is the signal input on the right-hand side between the red arrows?
The thick silver wire reaching the thoroidal from the right, shouln't it have a protective shed?
You are looking at a multi-tap printed resistor. The "blackish stuff" is the resist. the fatter ones are higher value resistors. The bond wires are to jumper over resistor values not desired. We use those as variable resistors.