xuhaoz wrote on May 18^th, 2010, 6:15am:
There are two options for treatment of 52MHz signal.

(1) Treatment of 52MHz signal as Small Signal in Small Signal Analysis subjected to master Large Signal Autonomous Steady State Analysis.

(2) Treatment of 52MHz signal as Large Signal in two Large Signals Autonomous Steady State Analysis.

See the followings.
http://www.designers-guide.org/Forum/YaBB.pl?num=1204880225/5#5
http://www.designers-guide.org/Forum/YaBB.pl?num=1151438219

xuhaoz wrote on May 29^th, 2010, 6:28am:
Autonomous Large Signal Steady State Analysis.

If you use Agilent ADSsim(RFDE), use HB Analysis.

If you use Agilent GoldenGate, use CR Analysis.

If you use Mentor EldoRF, use ".SST" Analysis.

If you use Synopsis HSPICE RF, use ".HB" Analysis.

If you use Cadence Spectre, use PSS Analysis.

xuhaoz wrote on May 29^th, 2010, 8:13am:
What do you mean by "pss in cadence" ?
We can use many simulators such as HSPICE, BDA's Analog FastSPICE RF, ADSsim and GoldenGate in Cadence ADE.
Do you mean "PSS in Cadence Spectre" ?

If there is a common divisor frequency in {fvco +/- 0.5*fvco, fvco +/- 52MHz, fvco/2, fvco/4, fvco/60}, you might be able to use PSS which is Large Signal Steady State Analysis based on one fundamental frequency.
If "fvco +/- 52MHz" are not included in frequencies or you treat 52MHz signal as small signal, a common divisor frequency is fvco/60.

Again there are two options for treatment of 52MHz signal.
How do you treat 52MHz signal, small or large ?
Do you understand meaning of "small signal" and "large signal" in simulation ?

Again surely see http://www.designers-guide.org/Forum/YaBB.pl?num=1204880225/5#5

The followings are general notes for you.

- Always describe correct tool's name and vendor's name which you use as tool or simulator.
- Don't do multiple posts which are same content.
- Don't request source code or behavioral model without any efforts.
- There are many simulators which have analyses called as PSS, PAC and Pnoise.
- Describe in detail with using correct terminologies.
- Warnigns are different from Errors.
- ADS is not name of simulator.
- There is no tool which name is Cadence.
- Don't use Direct Plot of Cadence ADE blindly without knowing definition.
- All gains in Direct Plot of Cadence ADE are "right", "true" and "practical" voltage gain.
- Don't mix up Simulation with Post Processing. They are completely different phase.
- MATLAB are different from Simulink.
- Learn measurements using actual instruments. Not "EDA Tool Play

xuhaoz wrote on May 29^th, 2010, 10:17am:
"virtuoso 6.1" is not name of simulator.
We can use many simulators such as HSPICE, BDA's Analog FastSPICE RF, ADSsim and GoldenGate in virtuoso 6.1.
Again use correct terminologies.

xuhaoz wrote on May 29^th, 2010, 10:17am:
Even if the circuit doesn't have a good isolation between each block, fundamental frequency of circuit is fvco/N. Here N is total divide ratio.

See http://www.designers-guide.org/Forum/YaBB.pl?num=1268969030/7#7

xuhaoz wrote on May 29^th, 2010, 10:17am:
If divide ratio truely changes dynamically at random, use envelope analysis or transient analysis.
This case is not periodical state, although I don't think such analysis is required for your case.

xuhaoz wrote on May 29^th, 2010, 10:17am:
It seems fundamental frequency is 26MHz, although I don't know other frequencies which are "etc.".

I assume fvco is around 3120MHz, fundamental frequency is 3120MHz/120=26MHz.

xuhaoz wrote on May 29^th, 2010, 10:55am:
Yes, although still I don't know what simulator's PSS you use.

Again see http://www.designers-guide.org/Forum/YaBB.pl?num=1268969030/7#7

If you observe spurious frequecies which are not expressed as M*fund_freq in actual measurement, you should suspect parasitic oscillation in circuit, e.g. bias circuit.

See http://www.designers-guide.org/Forum/YaBB.pl?num=1268385779/3#3