Hello,

In the attached file there is a double balanced passive mixer, i read thet this mixe with a passive filter in the output it work in turn as a fileter. To verify this condidtion I have to evaluate the impedence at the input of this mixer (how you can see in the attachet file). but This impedence is time variant, how can I do to evaluate this impedence??
Thank you

Thank you,

I cn use PSS+PAC analysis, but I have some question about this. To evaluate the time invariant inpedence. In the input port how do i have set "Source type"? Do i have ti set "PAC magnitude" equal to 1?
In PSS analyses how can choose the beat frequency? And the number of harmonics?
And in PAC analyses how can choose the MAXIMUM sideband?

Thank youuuuuuuuuuuu very much

Ok thank you, but I have another quastion sorry...after the pss and pac analyses I can plot corrent and voltage, but I want print the impedence, hence V/I, I thought to use calculator to make this, using the comand Vf and If , but I don't get any results.
How can I do??

Thank youuuuuu very much

Thank youuuuu...  I used results browser and saw how it works on   cadence cadence documentation, but in this documentation does not explain that when i choose e current node there is four choose  (PLUS,n,ns,ps) what is you meaning?  

Where can I find information about other ways to evaluate the impedance?

Thank youuuuuuuuuuuuuuuuuuuuuuuuuuuu

Hi,


for cadence spectre, the way I normally check the input impedance of a passive mixer would be to run PSS/PSP analysis. You can then plot the Z parameters or the Y parameters of the input port.


cheers,
Aaron

aaron_do wrote on Apr 23^rd, 2009, 7:29pm:
If you use PSP or QPSP of Cadence Spectre, you have to use "analogLib/port" which results in load at observation nodes.

Such loads at observation nodes are not preferable especially for interstage impedances measurements.
Here even if you increase port resistance, it can not be a solution.

I use my own impedance probe. For example, the following is single-ended impedance probe.
http://www.designers-guide.org/Forum/YaBB.pl?num=1221012939

In Agilent ADSsim, such impedance probe(Short_Probe or SP_Probe) is provided as standard probe.
http://edocs.soco.agilent.com/display/ads2009/SP+Probe+%28S-Parameter+Probe%29
But I can't use this ADSsim's probe in Cadence Spectre.
And this probe is restricted to only conventional SP-Analysis.

Instead I created my own impedance probe by using vsources, isources and ideal-transformer.
This impedance probe is valid not only for Agilent RFDE(ADSsim) but also for Cadence Spectre.
And this impedance probe is valid not only for conventional Small Signal AC Analysis but also for Small Signal AC Analysis subjected to Master Large Signal Analysis such as HB-SS of Agilent RFDE(ADSsim) and PSS/PAC of Cadence Spectre.

Assume cascaded connections of LNA, Mixer, Filter and IF_Amp, etc.
How do you measure any interstage impedances which see left and right ?

I can measure any interstage impedances using my own differential impedance probe.
Here I can evaluate Zleft_diff, Zleft_comm, Zright_diff and Zright_comm of any interstage at same time.


Ken Kundert wrote on Apr 23^rd, 2009, 11:47pm:
We all know any vendor's RF simulator except for very old one such as "SuperCOMPACT" does not require the use of ports as sources.

In the circuit, I replaced Nmos with ideal switches, so that i can neglect the problem due to design these.

Help me please please, I do not know how to go on ...

Sorry, Where can I find the useful material to learn??

However thank you very much for the other advice