I am trying to run PSS simulation for injection locked oscillator but sometimes I get convergence issues. I tried changing the integration method to gear2 and adding cmin=1f but still getting convergence error.
Could anyone explain the possible reason for it? The beat frequency is 50MHz (same as injection frequency) and oscillator frequency is 5GHz. I am using tstab=100ns.
I am using the following settings for PSS:
   start = 100.205 ns
   outputstart = 0 s
   stop = 120.205 ns
   period = 20 ns
   maxperiods = 25
   steadyratio = 100e-03
   step = 120.205 ps
   maxstep = 50 ps
   ic = all
   useprevic = no
   skipdc = no
   reltol = 100e-06
   abstol(V) = 1 uV
   abstol(I) = 1 pA
   temp = 27 C
   tnom = 27 C
   tempeffects = all
   errpreset = conservative
   method = gear2
   lteratio = 3.5
   relref = sigglobal
   cmin = 1 fF
   gmin = 1 pS