perturbation projection vector (PPV)

perturbation projection vector

hi all,

i need to find the perturbation projection vector of a LC oscillator. Can someone tell me how can i find that. I know that i have to do some sort of simulation in spice but what exactly do i have to do?

thanks much.

perurbation projection vector

I think you have to point out a change in some network variables depending on a pertubation source.

If for instance the pertubation source is a changing device current of an active device in your oscillator then you have to run two simulations. One with, the other w/o the pertubation current on. Then compare the difference over time, typical over a period.

There is also a typical characterisation which is called "impulse sensitivity function". There the pertubation source is a impulse which is a very fraction of the oscillation period. Most setups use a gaussian function. The change of phase depending on the actual position within the period is then plotted. It gives insight at which phases the oscillator is sensitive to pertubations.