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Simulators >> RF Simulators >> Is it possible to use QPSS and QPNoise to simulate the jitter in SpectreRF?
https://designers-guide.org/forum/YaBB.pl?num=1506080183

Message started by Jacki on Sep 22^nd, 2017, 4:36am

Title: Is it possible to use QPSS and QPNoise to simulate the jitter in SpectreRF?
Post by Jacki on Sep 22^nd, 2017, 4:36am

Hi,

Normally if PSS cannot find a steady-state for a two-tone system (for example, oscillator with modified supply), we can always go to transient noise simulation for a long run, and get the jitter.
Since QPSS is used for multi-tone system, is it possible to simulate the jitter by QPSS and QPNoise directly as in PSS and PNoise?
If anybody knows if Cadence has the application note about the QPSS simulation, because currently most I can find is PSS related simulation.
Thank you.

Title: Re: Is it possible to use QPSS and QPNoise to simulate the jitter in SpectreRF?
Post by sheldon on Sep 22^nd, 2017, 3:45pm

Jacki,

QPSS can't be applied to this problem. The oscillator is a driven circuit,
while the power supply is being driven. Mixing autonomous and driven
periodic state simulation is not supported in QPSS, as I remember.

There are several options:
1) Create a PWL source of your noise and perform a transient analysis
of the oscillator. There is an example, of using this approach for a
driven circuit in ADC RAK. The example shows the jitter calculation
for an ADC clock driver due to switching power supply noise on VDD.
2) Try semi-autonomous analysis, there is limited support for mixed
autonomous-driven support in Harmonic Balance analysis. Not sure
if it works with jitter analysis so you may need to manually do the
jitter calculation.

Sheldon

Title: Re: Is it possible to use QPSS and QPNoise to simulate the jitter in SpectreRF?
Post by Jacki on Sep 24^th, 2017, 11:58pm

Hello sheldon,

Thank you for your reply. I am thinking if QPSS and QPNoise can plot the spectrum density of the noise (phase noise), then I can integrate the noise and calculate the jitter. I am not starting the schematic yet, just consider the possible ways to do it.

Best regards,
Jacki