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    Noise effects in a power source in ADS

    Hi everyone,
    I am using ADS and i have modeled a circuit with 2 input ports and 4 output ports using a .s6p file.
    I am using P1tone power source with the two input ports.
    I am using Harmonic Simulator and S parameter simulation controllers.
    At output i am doing analysis on the voltage signals at 4 output ports.
    I want to add Additive White Guassian Noise (AWGN) effects with the P1tone source, to simulate real time noise effects in a received/intercepted signal and how it effects my output voltages. I could only find an option of phase noise that can be added to the P1tone power source.
    Frequency of operation is 3-10 GHz.
    Any help would be appreciated.
    Thankyou

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    Re: Noise effects in a power source in ADS

    I'd tend to doubt that white noise is your biggest
    power supply "aggressor". A thing to characterize,
    sure, why not.

    But if you're after an estimate of in-application
    spectral purity, I believe you'd like to mock up
    a realistic power supply and inlet filter subcircuit
    to run your signal chain, off of.

    Figuring there's a switcher upstream somewhere,
    maybe a linear to clean it up (as best it's able)
    and your chokes, caps and what-not between
    the prime source and your circuit, and not one
    bit of this looks much like white noise.


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    Re: Noise effects in a power source in ADS

    Since you use s6p Touchstone s-parameters file and they have no information about Noise of 6-port device, it doesn't make sense to add a Noise to Power Source..
    You confuse essentially small signal and large signal analysis.I have repeated many times here, s-parameters are small signal network parameters and they don't include any information about nonlinearity of the circuit so using of HB is nonsense.. You can do transient analysis to observe port voltages and currents but HB is done to essentially predict the nonlinearity of the circuit.So applied voltage/current will exit as linearly but with no harmonics.
    Since they have no information about circuit's noise, adding a noise information to the Port will not work..


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    Re: Noise effects in a power source in ADS

    Quote Originally Posted by BigBoss View Post
    Since you use s6p Touchstone s-parameters file and they have no information about Noise of 6-port device, it doesn't make sense to add a Noise to Power Source..
    You confuse essentially small signal and large signal analysis.I have repeated many times here, s-parameters are small signal network parameters and they don't include any information about nonlinearity of the circuit so using of HB is nonsense.. You can do transient analysis to observe port voltages and currents but HB is done to essentially predict the nonlinearity of the circuit.So applied voltage/current will exit as linearly but with no harmonics.
    Since they have no information about circuit's noise, adding a noise information to the Port will not work..
    Thankyou for swift response,
    Yes, maybe thats the reason i am not getting any effect on the output voltages even though i am adding phase noise or non linear noise present in HB.
    Actually i am sweeping phase in one of the P1tone (simulating phase difference between input signals) and then computing I/Q signals from the output voltages and from them i am calculating the measured phase difference.
    I wish to simulate some noise effect at source, to see the effects on my output voltages (I/Q signals).
    Can u please suggest what kind of simulation i should use and how to add noise.
    Thankyou

    - - - Updated - - -

    Thankyou @dick_freebird and @bigboss for rapid and valuable responses.
    I am just using P1tone as two power sources feeding into a .s6p symbol that has four output ports. I am using voltage signals at 4 output ports to give me I/Q signals. From I/Q i measure phase difference between input signals
    i need to simulate realistic noise environment which can have some deteriorating effects on the output I/Q signals.
    Can you please suggest which simulation controller can be added in ADS and how a noise environment can be simulated. Maybe some noise block which adds noise in P1tone power source.
    Thankyou very much



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    Re: Noise effects in a power source in ADS

    If you would like to see the noise effect of the circuit on overall circuit performance, you should do those :

    -Change the s6p Black-Box that covers no noise information with an equivalent circuit with noisy elements( I believe it's a Poly-phase Filter) .
    -Do a HB Simulation with Nonlinear Noise Option in the HB controller and observe Phase Noise coming from the perturbation caused noisy elements.
    But as I said before, your circuit is linear so there will be no harmonics at the output so you will observe the main carrier and its skirts by doing Phase Noise simulation.


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    Re: Noise effects in a power source in ADS

    Hello Bigboss,
    I am now using a look alike EM model of the six port network simulated in Momentum instead of using S parameter blackbox as you advised earlier.
    I am generating non linear noise from Harmonic Balance simulator but my output voltages from the six port network are not affected.
    I have also tried phase noise modulated power sources but my outputs remain unaffected.
    I have found "Noise Channel" and "AWGN channel" symbols in ADS help but can not find them in library or component pallette.
    Can you please guide me how to use them. I am using ADS version 2017 update 1.
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    Thankyou very much. Aim is just to show the effect of channel noise in transmission medium on output voltages.
    Bilal



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    Re: Noise effects in a power source in ADS

    Dear bilal.habib,

    Since your circuit has no information about noise which is created in it, you cannot achieve any meaningful result.In order to get a consistent result from a Noise Analysis, the circuit itself must contain noise information to be treated.


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