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Resistor Parasitic Capacitance and RF Operating point

Thread starter #1
As a reference to my question; I know that a 10K ohm resistor that has a parasitic capacitance of .3pF at 200MHz will have a actual impedance value of 2.564K ohms. If this resistor is used in a bias network for an RF amplifier, how does this shift in resistance effect the RF operating point? What is the RF operating point? I know what the DC operating point is but I don't know what the RF operating point is.


Well-Known Member
Most Helpful Member
You did not post your circuit, so my answer is not as good. Assume this resistor pulls the Base of a transistor up, the DC and the average voltage of the AC are the same. The RF will see a 0.3pF cap to the supply so some of the signal may be attenuated.

The RF operating point does not change because of the 0.3pF.


Well-Known Member
Most Helpful Member
I can tell you that in some instances mounting a resistor on it;s side will reduce parsitic inductance and three resistors in series may have lless parasitic inductance than a single value. Tidbit.

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