Dear all,
I have tried to re-do the post layout simulation of whole module. I find that the parasitic makes the noise match and conjugate match value with larger different. If I made noise match, it could give out a better NF value but worse input impedance, and vice versa. In the post simulation, if I did the noise match, the NF=1.8dB and S11=12dB. On the other hand, if I did conjugate match, the NF=3.2dB and S11=22dB. In the post layout simulation, I use RC extraction view and include the bondwire model. (the bondwire model just constructed by myself). The problem appears in the measurement. I did the measurement in package on PCB. I have tried to do the noise match. It just gives me NF=4dB and S11=6.5dB. I don't know why so high NF is gotten. Do you have any idea about this? Or, what kind of things could I improve in next tape out?
Thanks
wccheng