Stats

  • Locked Locked
  • Replies 1
  • Subscribers 125
  • Views 12815
  • Members are here 0
This discussion has been locked.
You can no longer post new replies to this discussion. If you have a question you can start a new discussion

Phase Noise at PIO vs. Parameter

baenischfau

Hi there,

I'm simulating a VCO at the moment and I want to create a plot which shows

PhaseNoise@100kHz vs. tuning voltage of the VCO. However I'm having trouble

in getting the plot.The simulation is a PSS simulation with PNOISE that uses

a symbolic parameter that tracks with vdd to ensure that vtune does not exceed

the supply voltage. This range is then divided into 30 intervals to simulate PhaseNoise

at different VCO frequencies.

I get the various PhaseNoise plots but if I apply a value measurment @ 100kHz

to the waveforms I only get a single waveform measured.

The generated measurement within the calculator looks like this:

 

value(value(_drplPmNoise(?modifier "dBc") "vtune" 0.0) 100k)

 

which indicates that only the waveform with a tuning voltage of 0.0 is considered.

I have extended the list to include more voltages and it works but this approach

has some negative side effects if I change to supply voltage and therefore also the

voltage tuning range of the VCO. As the intervall is tracking with vdd I get different

voltages each time I change the settings for the supply :(

Is there an easy way to tell ADE that I just want a value measurement for all available

graphs without having to specify tons of voltage values ?

 

Best Regards

 

Andi

  • Andi,

    That's odd. I don't know how you did the sweep (or which version you were using), but normally the inner sweep should be the frequency sweep of the pnoise analysis, and the outer sweep would have been whatever you set up as the sweep on the PSS analysis form (assuming that's what you did - you really didn't describe the sweep setup) or using Tools->Parametric analysis in ADE.

    So it ought to work using

    value(_drplPmNoise(?modifier "dBc") 100k)

    To remove any ambiguity about which variable you wish to slice though in the value function, you should be able to do:

    value(_drplPmNoise(?modifier "dBc") 'freq 100k)

    (From the expression I'm assuming you've set up to use "modulated" or "jitter" mode (in FM mode) on the pnoise form).

    Regards,

    Andrew.

Community Guidelines

The Cadence Design Communities support Cadence users and technologists interacting to exchange ideas, news, technical information, and best practices to solve problems and get the most from Cadence technology. The community is open to everyone, and to provide the most value, we require participants to follow our Community Guidelines that facilitate a quality exchange of ideas and information. By accessing, contributing, using or downloading any materials from the site, you agree to be bound by the full Community Guidelines.