In this document:
there is in the equation below Figure 6 on page 4 a variable that is a Beta symbol with the subscript "re". I know what Beta without the subscript is, but this is the first time I have seen that subscript with it as it is in that equation's numerator. This has resistance units. What transistor parameter value is this? I suspect it is one I already know by a different symbol. Could this be the incremental emitter resistance I know as the symbol r with the geek letter pi subscript?
In that equation there is the symbol Rs which I know to be the source resistance the noise figure was measured with. I need to figure out what this value is from data available for this transistor:
which has numeric data available for the Smith Chart data shown in the spec sheet PDF as a download.
Is calculating Rs matter extracting it from reflection coefficient data by solving for the real part of Zs in the second equation at:
Or is Rs simply the typical 50 ohm source impedance which is also the typical characteristic impedance of cable?
In the tuning networks for making noise measurements is the load in that reflection coefficient equation always only a reactive element without a real part? And is the source always only a real element with no reactive part?