how to measure input impedance of gilbert mixer in cadence

[jignesh_prajapati]

hi
i m have designed gilbert mixer now i m trying to find its input impedance. i have used single to differential network (not balun) for Rf and LO port. now how input impedance is measured i m working in cadence spectre. anyone have some idea please reply me.

 

[BigBoss]

LO Input Impedance has less importance compare to RF/IF Input Impedance because LO port is driven hardly to commutate the mixer pairs.RF/IF Input Impedance can be found easily by
s-parameter simulation or LSSP simulation.Differential impedances are found by termination "port" component to associated inputs.Then you should check Sxx on the Smith Chart or look at ZMx.

 

[vfone]

If you don't have too much experience doing VNA differential measurements (and simulations), would be better to use a balun because you can choose the right impedance ratio of the balun, as in the list below from TDK:

**broken link removed**

For using a simulator, TDK provides the S-parameter data for those baluns:

https://product.tdk.com/en/technicalsupport/tvcl/general/balun.html