Does the optimum source reflection coefficient change when adding resistor?

[skatefast08]

Does the optimum source reflection coefficient change when adding a shunt resistor (500 ohms) to a transistor amplifier? For example, for an ATF-55143 transistor, the optimum source reflection coefficient for the amplifier (bias: 2.7V Vds and 10mA Vds) is at 0.45/59.8(degrees), as shown in the image below (figure 1). If I added a resistor in shunt (as shown in figure 2) at the output of the transistor amplifier, wouldn't that change the magnitude and angle of the optimum source reflection coefficient? if so, then how can I determine the new optimum source reflection coefficient after adding a resistor at the output of the RF amplifier?

figure 1:


figure 2:

 

[pancho_hideboo]

If I added a resistor in shunt (as shown in figure 2) at the output of the transistor amplifier,
wouldn't that change the magnitude and angle of the optimum source reflection coefficient?

No change.

Consider equivalent cascade model.

Noise-Model + Noiseless-S2P
https://edadocs.software.keysight.com/pages/viewpage.action?pageId=6071545
https://edadocs.software.keysight.com/pages/viewpage.action?pageId=5916651

 

[BigBoss]

Optimum Noise Impedance is an Intrinsic Parameter of a Transistor so adding any element does not change this Impedance.