PSS simulation for VCO

Hello , i have found that my VCO oscilates 13.45GHZ by converting period to frequency from the transient plot bellow f=1/T,

i  tried to perform the PSS and PNOISE as following:

PSS: 

tbstat=30.48nsecnsec (the transient of the signal,from the plot bellow the steady state starts after 30.48ns ,tbstat help definition is shown bellow bellow)

Beat frequency=13.45GHZ(its the high common input frequency, from my transient response i calculated the oscilation frequency by f=1/T)

PNOISE:

Relative frequency: the help shown bellow says we should use 2 because we have diodes in it(so i am not sure, my diodes are used as a varactor)

 frequency range: i thought to specify the range from zero till the frequency of the oscillation i got fro the transient plot and f=1/T.

The final ADEL shown bellow.

When i tried to run the PSS first ,it gave me an error shown in the end.

Why it gave me an error? my VCO is oscillating fine  as you can see in the transient plots bellow.

a step by step of what was done shown  is bellow. 

Thanks

*****************************************************************************************************

pss: time = 30.08 ns (97.5 %), step = 2.974 ps (9.64 m%)

Error found by spectre at time = 30.8517 ns during periodic steady state analysis `pss'.
ERROR (SPCRTRF-15050): V(out_p,out_n) is too small to reliably detect the period of the oscillator.Perhaps nodes with insignificant signal levels were chosen, or perhaps the oscillator was never properly started.

Analysis `pss' was terminated prematurely due to an error.
modelParameter: writing model parameter values to rawfile.

Opening the PSF file ../psf/modelParameter.info ...
element: writing instance parameter values to rawfile.

Opening the PSF file ../psf/element.info ...
outputParameter: writing output parameter values to rawfile.

Opening the PSF file ../psf/outputParameter.info ...
designParamVals: writing netlist parameters to rawfile.

Opening the PSFASCII file ../psf/designParamVals.info ...
primitives: writing primitives to rawfile.

Opening the PSFASCII file ../psf/primitives.info.primitives ...
subckts: writing subcircuits to rawfile.

Opening the PSFASCII file ../psf/subckts.info.subckts ...

Aggregate audit (9:14:04 PM, Fri Jan 11, 2019):
Time used: CPU = 1.39 s, elapsed = 1.53 s, util. = 91.1%.
Time spent in licensing: elapsed = 31.2 ms.
Peak memory used = 58.1 Mbytes.
Simulation started at: 9:14:02 PM, Fri Jan 11, 2019, ended at: 9:14:04 PM, Fri Jan 11, 2019, with elapsed time (wall clock): 1.53 s.
spectre completes with 1 error, 5 warnings, and 4 notices.