I have attached layout of the cascode LNA. Left most is LG, top one is LD and bottom one is LS. Whenever I try to move LS and LD away from their place and away from each other, the following error appears for post-layout s-parameter simulation after RLCK extraction. This error also appears whenever I try to change the capacitor associated with those nodes net 34:38.
"Notice from spectre during topology check.Only one connection to the following 4 nodes:
I0.net34 I0.net35 I0.net38 I0.4\:GND
No DC path from node `I0.net34' to ground, Gmin installed to provide path.
No DC path from node `I0.net35' to ground, Gmin installed to provide path.
No DC path from node `I0.net38' to ground, Gmin installed to provide path.
Fatal error found by spectre during topology check.
FATAL: The following branches form a loop of rigid branches (shorts) when added to the circuit:
I0.VR2_15:p (from I0.IN#23RLJUNC15TR0 to I0.IN#23RLJUNC15TR98)"
What is the reason for this and how it can be resolved?
Regards,
Vinay