Re: [time-nuts] Spice simulation of PSRR and phase noise

Am 22.10.2017 um 22:58 schrieb Bruce Griffiths: Hoi Attila Since close in phase noise can result from up conversion of supply noise etc via circuit non linearities, using an AC analysis won't work. Only transient simulation or perhaps analytical modelling of the various non linearities will p

Re: [time-nuts] Phase Noise Modeling in SPICE

Eric has done a lot of excellent work, I know his presentations . While I do no always agree with the ADS approach and use my own software the ADS is a very good all-round CAD microwave CAD tool. More on the topic addressed you will find under      http://www.microwavejournal.com/articles/29151

Re: [time-nuts] Spice simulation of PSRR and phase noise

One has to provide noise models that work with the Spice transient simulation for all devices including resistors. Random number generators can be used but they need to be independent and must not repeat during the entire simulation. Bruce > > On 23 October 2017 at 10:25 Bruce Griffiths

Re: [time-nuts] Sulzer 2.5 For Sale

Hi Ruslan, > this standard appears to be ancient Yes. Sulzer oscillators are among of the best quartz frequency standards ever made. Good reading: "Brief History of the Development of Ultra-precise Oscillators for Ground and Space Applications" https://ieee-uffc.org/about-us/history/uffc-s-hi

[time-nuts] Phase Noise Modeling in SPICE

I have done a lot of phase noise modeling using LT SPICE over the years for PLL’s. It will not model the phase noise of the individual devices like VCO’s, dividers, phase detectors. You can input the phase noise profiles of the various devices and it will give the output phase noise of the loop

Re: [time-nuts] Spice simulation of PSRR and phase noise

If one for example wishes to estimate PN down to an offset of 1Hz then an equivalent filter noise bandwidth of 0.1Hz or perhaps less is desirable (the PN spectrum at low offsets is far from flat). To achive accurate noise estimates a simulation time of at least 100 x the reciprocal of the equiv

Re: [time-nuts] Spice simulation of PSRR and phase noise

Hoi Attila Since close in phase noise can result from up conversion of supply noise etc via circuit non linearities, using an AC analysis won't work. Only transient simulation or perhaps analytical modelling of the various non linearities will provide accurate estimates of upconverted PN. If yo

Re: [time-nuts] Spice simulation of PSRR and phase noise

Dear Attila, you haven't specified what sort of circuits would you like to simulate, but maybe the answer is Harmonic Balance. Have a look at http://qucs.sourceforge.net/ and http://qucs.sourceforge.net/tech/node36.html HSPICE from Synopsis and ADS from Keysight (which I use) also have the

Re: [time-nuts] Sulzer 2.5 For Sale

That system clearly is a rudimentary (simply based on amplitude) failover controller---e.g., a shoestring setup could have an EOL cesium standard (relatively-accurate but -unreliable) that's not on UPS and a UPS-backed OCXO (like this unit) (relatively-inaccurate but -reliable) connected to ``REF I

Re: [time-nuts] Spice simulation of PSRR and phase noise

Hello Attila, It seems to me that an AC simulation could never work since the very generation of phase noise by the mechanisms that matter is a modulation process at heart, automatically forcing one into the realm of transient simulations. But I am surprised about the simulation times that you sp

[time-nuts] Spice simulation of PSRR and phase noise

Hi, I have been looking into spice simulations of circuits, in particular trying to extract PSRR and phase noise information. Unfortunatelly, the obvious way of putting AC sources at the right places does not work, as the (ideal) input signals are not small and drive the circuit into non-lineariti