I am design Gilbert Mixer for RF front end of Zigbee System in Cadence how to do analysis of s-parameter of mixer i did PSS and PSP for that but it give unexpected result and how to decide start and stop frequency in psp what is significance of that.
please someone help me ....



Thank you

Thank you sir for reply .....
In this PDF the IF and LO port connect with VCVS and i cant analysis of S22(IF), S33(LO) than how am i ensure that output is matched to 50 Ohm.
I did PSP aith PSS analysis in cadence for S-Parameter analysis.
I matched RF at 50 Ohm and got S21 is 4dB when i connect simple port at IF with a capacitor without VCVS but in this case IF port not perfect matched, but when i use VCVS at the IF my S21(gain) increase 20dB. Is it correct.  
help me some one its urgent to me..

Thank you
kapil soni