yannis wrote on Apr 17th, 2009, 12:38pm:and calculate the large signals s-parameters through psp.
Not correct. S-parameters calculated by PSP of Cadence Spectre is Small Signal S-parameters.
As far as I know, PSP and QPSP of Cadence Spectre are not used so much.
So there are many bugs in PSP and QPSP.
See
http://www.designers-guide.org/Forum/YaBB.pl?num=1208334972/21#21yannis wrote on Apr 17th, 2009, 12:38pm:I was wondering if there is any way to simulate in spectre the power conversion gain (and possibly the NF and IP1dB) of a mixer, under the assumption that the RF and LO ports of the mixer are conjugently matched with the ports that drive them.
I can't understand what you mean by
IP1dB. Is it Input referred 1dB Gain Compression Point ?
I have no answer for Cadence Spectre because I don't use Cadence Spectre for RF circuits design.
But you might be able to find some informations useful for you in the following.
http://www.cadence.com/Community/blogs/rf/archive/2009/02/09/shhhhh-spectrerf-tu...yannis wrote on Apr 17th, 2009, 12:38pm:I was thinking if there is a more elegant solution that can also be applied for IP1dB.
There is no elegant method in real RF measurent using actual instruments.
http://www.maurymw.comMixer is operated by non-linearity.
Higher harmonics are always generated in input currents due to non-linearity of DUT even if driving signal have only one frequency.
This is vey true for LO port.
Input impedances of DUT are different between all harmonics including fundamental.
Assume Zin(n*f0),n=1,2,3,4,5,....., generally they are all different.
Input impedances, Zin(n*f0) are affected by power level and fundamental frequency, f0.
Input impedances of RF port are also affected by LO conditions.
http://www.home.agilent.com/upload/cmc_upload/All/1_NVNA_and_X-parameters_in_ADS...I use Agilent ADS(RFDE) or GoldenGate for RF circuits design.
If you use Agilent ADS(RFDE) or GoldenGate, you can do simulation for your purpose, here you can set reactance for Port components.
I don't use LSSP(Large-Signal S-Parameter Simulation) for this purpose.
You heve to consider following issues.
http://www.designers-guide.org/Forum/YaBB.pl?num=1231854969/5#5http://www.designers-guide.org/Forum/YaBB.pl?num=1231076499/8#8You can set port impedances for fundamental frequency and it's harmonics separately.
Here you can add both fundamental frequency and power dependencies for this port impedance using DataAccsess Component of ADS(RFDE).
http://edocs.soco.agilent.com/display/ads2009/DataAccessComponent+%28Data+Access...http://edocs.soco.agilent.com/display/ads2009/P+1Tone+%28Power+Source%2C+Single+...http://edocs.soco.agilent.com/display/ads2009/Load-Pull+SimulationsYou can do Source-Pull Simulation although the above example is Load-Pull.
Also you can do automatically search and set conjugete matching impedance for Port without using DataAccsess Component of ADS(RFDE).