I am trying to measure the ouput impedance of LNA ( without matching circuit at the output port) . I have attached 2 set ups for calculating the Zout using S parameters.
1) First circuit includes the inductance at the drain as a load with port.
2) Second circuit includes just a port at the load.
Which set up is correct?
How do we set the port resistance for output impedance calculation ? Is there anything else that I need to set up in the port ?
Should I only ground the ac and leave the dc bias in the circuit while I am calculating the output impedance ?
Can anyone help me with this please ? I have been working on measuring the output impedance of LNA using sp and psp.. I am very confused. Please advice.
Neither one..
When you do s-parameter simulation, you should terminate each port with PORT element to able to measure input and output impedances and the Gain.
When you say port element, Do you mean by its resistance ?
If yes then how do we see whether our circuit ( Amplifier's output) output impedance is matched to 50 ohms or not ?