Conversion Gain Measurement-Spectre RF

[hrkhari]

Hi Guys:

Why is the conversion gain measured in a PSS analysis differs from the conversion gain measured in PXF analysis for a designed mixer in Spectre-RF?. Thanks in advance

Rgds

 

[Mazz]

PXF analysis is intended to give an indication of different gain vs product indexes, while PSS is the most accurate one.
For example you can use PXF to see if there is image rejection or if you want to know how large can be an unwanted output frequency out of the non linear circuit under evaluation.
With PSS you ussually perform all analysis to really design the mixer: P1dB, IP3 and so on.
I hope it can help
Mazz

 

[hrkhari]

Hi Mazz:

Do you mean that PXF is most suitable to measure the LO-RF and LO-IF isolation?.

I came a across a Cadence documentation that states conversion gain measured in PXF analysis includes the effect of input output matching , whereas the conversion gain measured in PSS analysis does not take into account the matching effect.

On the other hand I had contacted Cadence support team on Spectre-RF on this issue and it is stated that the conversion gain measured both in PXF and PSS analysis should be the same.

Can you comment further on this statements. Thanks in advance

Rgds