Mixer large signal impedance with PSS/PSP

I noticed something wierd while simulating a switching mixer impedance using PSS and PSP. The impedance seen is dependent on the port's impedance (which it shouldnt be). Any inputs on why this is happening will be helpful!

In switching mixer(maybe passive mixer), the output port can be seen from input under PSS(LO driving),
so it's natural that input impedance is dependent on output port resistance.

Rather why do you think the input impedance should not be dependent on the output port's impedance ?

Also input impedance could be dependent on input port's resistance.
See http://www.designers-guide.org/Forum...1052660826/1#1

Thanks for your reply,
As you guessed, its a switching mixer. I just have one port on the baseband side that I use to see the impedance. The RF side of the Mix is terminated with a fixed load. Based on your reply, if the termination is fixed, then shouldnt the impedance seen be also fixed, regardless of what port impedance I use?
Regards,

Your mixer is for TX, that is, upconversion from baseband to RF ?
Do you set each port like following ?
LO ; type=sine
IF(BB) ; type=dc
RF ; type=dc

IF(BB) is Input(Port 1).
RF is Output(Port 2).

Input impedance could be dependent on input port's resistance.
See http://www.designers-guide.org/Forum...1052660826/1#1

Thanks for the info and link. Yes I do setup the way you mentioned. Looks like the Large LO leakage into the BB node does affect a lot. Better to simulate with what is expected actually in layout.
Regards,

Hi,
I use PSS/PSP for simulating up conversion mixer.In this "LAB3_Mixer_2010.pdf" guide i found instruction, but i have error and simulation not complited.

ERROR (SFE-874): "input.scs" 87: Unexpected end of block statement "}".
ERROR (SFE-874): "input.scs" 95: Unexpected end of block statement "}"

Fif=2GHz, Flo=120GHz, Frf=122GHz.
What is it means?
Regards, Peter

pancho_hideboo, thank you for more advices. It is really very helpful. Actually i din`t understand what was problem. When i simulated analyses again (i didn`t load old state of analog environment, make again) all also work.
just in case i attached tutorial 'LAB3_Mixer_2010.pdf' and netlist of project.

regards, Peter

This means that I re-configure the parameters of analysis and simulation completed without errors.

Delete all your posts in this thread, since there is no issue to answer in your posts.