Mehran wrote on Dec 11^th, 2008, 6:25pm:

Mehran wrote on Dec 18^th, 2008, 11:51pm:

If your ILO(Injection Lock Osc.) could be enough locked within your simulation accuracy setting, a driven PSS can be valid for ILO where driven signal is injection signal.
If your ILO could not be locked, PSS can't converge. But you can't distinguish whether it is ILO unlock or PSS convergence fail due to PSS ill-robustness.

Use driven envelope analysis and observe instantaneous frequency of Nth harmonics you desire.
And using chirp FM signal or conventional FM signal as injection signal, you can evaluate lock range. Here frequency change speed must be enough slow compared to settling time of ILO.

But I can never assure simulation performance of envelope analysis in Cadence Spectre.

I use envelope analysis of Agilent GoldenGate simulator for this purpose.

Mehran wrote on Dec 21^st, 2008, 12:47am:

What spectrum do you get ?
I think you expect one remarkable peak spectrum at oscillation frequency but actual result is very wide spreaded where you can't  find any remarkable peak in spectrum. Right ?
Teach me followings.
 (1) Frequency of injection signal
 (2) Waveform shape of injection signal
 (3) Expected oscillation frequency

Mehran wrote on Dec 21^st, 2008, 12:47am:

Try a driven envelope analysis of Cadence Spectre.
Then observe instantaneous frequency of Nth harmonics you desire.

Mehran wrote on Dec 21^st, 2008, 12:47am:

This is same as actual measurement.
Do you have experience of actual measurement ? Not EDA Tool Play.

Your post is usage of simulator not Design issue.
Please post to "The Designer's Guide Community Forum ≫ Simulators ≫ RF Simulators".

Mehran wrote on Dec 21^st, 2008, 1:28am:

Do you mean your FREQosc is not equal to N*FREQinj where N is integer number ?

As far as I know, oscillation frequency of conventional ILO is N*FREQinj when it is locked.
So I can use a driven one fundamental PSS for ILO if it can be locked.

Have you invented a novel ILO whose oscillation frequency is not restricted to N*FREQinj ?
If so, you can not use a driven one fundamental PSS and you have to use autonomous two tone QPSS although Cadence Spectre doesn't have autonomous QPSS yet.

But if your ILO is conventional one where FREQosc is equal to N*FREQinj, autonomous QPSS is not completely appropriate.
In unlock state, oscillation could be never stationary or could disappear in steady state. So there is no solution for QPSS.
You have to use a driven envelope analysis.

Mehran wrote on Dec 21^st, 2008, 1:28am:

I can't access the above paper now but I think your result is natural since you do static DFT.

Mehran wrote on Dec 21^st, 2008, 1:28am:

Maybe this graph is a result of Max-Hold plot in Spectrum Analyzer.
In simulation using EDA Tool, I can plot such graph by using simulation results such as envelope analysis with chirp FM signal.
Or instead of chirp FM signal, I might use parametric sweep function for frequency of signal source in simulation.
But it requires script to create such graph.
Do you have a skill to write script handling simulation result ?

Rather I'm using plot in page.16 for ILO in both simulation and actual measurement.
It also requires scripts.

But I use Agilent post processing environment, so I don't have to write script.

Mehran wrote on Dec 22^nd, 2008, 5:39pm:

Did you understand an evaluation of an instantaneous frequency by using Envelope Analysis ?
An instantaneous frequency can be calculated like following.

In Agilent Tools.
 Inst_Freq=diff( unwrap(phaserad(out[N]), pi)/(2*pi) )+HB.freq[N]

In Cadence Tool.
 Inst_Freq=-groupDelay(harmonic(v("/out", ?result "envlp_fd"), N))+N*fund_freq_of_Envelope_Analysis

In your case, fund_freq_of_Envelope_Analysis=4444MHz and N=1.

Mehran wrote on Dec 22^nd, 2008, 5:39pm:

Do you understand
   "Max-Hold plot in Spectrum Analyzer",
   "parametric sweep function for frequency of signal source in simulation"
in my answer ?

Mehran wrote on Dec 22^nd, 2008, 5:39pm:

Almost all EDA vendor's tool have some languages for database, simulation and framework, etc.
You can use language called "skill(ocean)" in Cadence DFII environment.
First you should try manual procedure without scripts.
Here you have to know general procedure of actual measurement for VCO, PLL, etc. using actual instruments.
Many measurements using actual instruments are intensively used in both papers you refered. Not EDA Tool Play.

Mehran wrote on Dec 22^nd, 2008, 5:39pm:

I don't think so.
It is no more than simple and common usage of simulator.

Mehran wrote on Dec 28^th, 2008, 10:33pm:
I think this is due to very simple reason that your ILO can't work as ILO.

Mehran wrote on Dec 28^th, 2008, 10:33pm:
This is also due to very simple reason that your ILO can't work as ILO.

See page-24 of http://www.cmoset.com/uploads/7a.3.pdf
This Spectrum are measured by Agilent PSA or ESA Series Spectrum Analyzer of "positive peak" detector mode not "sample" detector mode.