There is problem in my LNA design, need help

[babydog0]

When i run LNA simulation, after finished , In Output log, i found "No DC path from node XXX to ground ". and "error" displays next to the balun port. In ADE, i run sp and dc simulation in sequence. i don't know why this happend.

this LNA has a differential CG stage, i directly couple the balun differential outports to the sources of CG MOS, i thought balun can offer a dc path to the CG stage, i don't know if am i right or wrong?
Actually, a balun should have 4 ports, one single-ended port, two differential ports, and a gnd port. But the balun i am using in Spectre only three ports, i don't know if Spectre balun default to include a gnd port.

 

[babydog0]

seems no one could help

 

[OldRFguy]

OK, I don't know which simulator your using here but when it says "No DC path from node XXX to ground ", have you tried putting a 10M resistor in the simulation from the node to ground to see if that clears the problem? It's a quick thing to try and it might help.