Now i study mixer by the software Cadence.I have some questions want to ask. I really feel headache.
I study a perfect ideal and symmetrical CMOS Gilbert cell mixer. I don't know how to get the LO-RF isolation. Some papers say their
LO-RF isolation is around 30dB or 40dB. But when I set LO = -10dBm, LO feedthrough at RF port = -110dBm. I feel quite strange. I have used two methods to obtain the LO leakage. One is PSS+PXF to get the LO signal gain at the RF port with RF source as DC, the other is only PSS analysis to get the RF port signal at those harmonics of fundermental frequency, therefore the signal power at LO frequency is obtained. Both of the two methods give me very low LO leakage. How do they get LO-RF isolation? who can help me?????????
I study a perfect ideal and symmetrical CMOS Gilbert cell mixer. I don't know how to get the LO-RF isolation. Some papers say their
LO-RF isolation is around 30dB or 40dB. But when I set LO = -10dBm, LO feedthrough at RF port = -110dBm. I feel quite strange. I have used two methods to obtain the LO leakage. One is PSS+PXF to get the LO signal gain at the RF port with RF source as DC, the other is only PSS analysis to get the RF port signal at those harmonics of fundermental frequency, therefore the signal power at LO frequency is obtained. Both of the two methods give me very low LO leakage. How do they get LO-RF isolation? who can help me?????????