Problem on running phase noise simulation in Hspice

[shaq]

running phase

Dear all,

I want to simulate phase noise in Hspice.

I write a testing script as shown below.

.HBOSC tones=1.3e6 nharms=15 PROBENODE=clk_out,0,1.25 FSPTS=20,1.25e6,1.35e6
.PHASENOISE V(clk_out) DEC 10 10K 10MEG METHOD=0

*******Results******************
.print hbosc vm(clk_out) vp(clk_out) vr(clk_out) vi(clk_out)
.print   phasenoise phnoise
.probe phasenoise phnoise
.probe hbosc v(clk_out) v(clk_out)

My oscillation frequency is 1.3MHz, so I set "tones=1.3e6," clk_out is the output node of the oscillator and 1.25 is a half of 2.5 of Vdd.
But, it takes me a lot of time on running simulation all the night.

Is anything going wrong in my script?

 

[ch1k0]

version hspice ? windows ? Linux ?

 

[shaq]

version hspice ? windows ? Linux ?

Hspice 2008.03, Linux version

 

[ch1k0]

kind oscillator ?
vco lc, free running ?
ring oscillator ?
hspicerf works good hbosc and phasenoise for lc vco.
ring osc different.

 

[shaq]

kind oscillator ?
vco lc, free running ?
ring oscillator ?
hspicerf works good hbosc and phasenoise for lc vco.
ring osc different.

ya, it's 5-stage ring oscillator.

 

[ch1k0]

increase nharms, 64 , 128, if hb.
ring osc best use sn, much harmonics.

 

[n1cm0c]

Use shooting newton analysis prior to phase noise extraction instead of harmonic balance. Your ring oscillator is working at a frequency much lower than the highest significant harmonic.

Or try spectre instead of hspicerf.

 

[anindya1012]

hi..I have designed a 10ghz LC oscillator and i need the code to measure its phase noise. can anybody please help me?