How to use PORT with mismatched impedance!

[plasma2000]

I have to design a mixer whose Zin=1000 Ohm. It will be connected to a LNA whose Zout<<1000 Ohm, so their impendances are mismatched.

So when I simulate the mixer, I have to use a port with a power (dBm) in it. But the PORT is a strange element, which maybe only could be used for impedance matched system, in order to obtain accurate results.

Is there any good buddy who has the experience to use it in this case, and can help me?

Thanx, Merci, Grazie, XieXie, 감사 ~!

 

[tsinghua]

Actually the port component is a voltage source in with the defined source resistance which is 50ohm im most applications. The power (in dBm) is the power will be delivered to the matched load. Hope this help you understand the behavior of your design.