向大家请教SpectreRF中瞬态仿真noise设置问题

wm1630 · 发表于 2012-5-22 18:41:58

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我想向大家请教SpectreRF中瞬态仿真noise设置问题，瞬态仿真中的noise怎么设置，选项有以下：
noiseseed_________；noisefmax______；noisescale____；noisefmin_________；noisetmin_____；multi runs；
noise runs___。它们的含义是什么了。我的软件打不开spectre的帮助文档
其实我是想仿真一下VCO的输出功率谱，把trans转换成DFT，不知道各位是怎么仿真VCO的输出功率谱的。
先谢谢大家了

zqlv · 发表于 2012-5-22 20:58:49

下面的帖子可能对你有帮助。

http://bbs.eetop.cn/thread-284411-1-3.html

zqlv · 发表于 2012-5-22 20:59:36

下面的帖子可能对你有帮助。

http://bbs.eetop.cn/thread-284411-1-3.html

wm1630 · 发表于 2012-5-24 07:46:41

回复 3# zqlv

非常感谢，这个正是我想找的。但是文档中还有点不太懂。我想把闪烁噪声的影响反应在频谱中。不知道瞬态仿真时间和噪声带宽的频率下限怎么设置。我现在设置的是瞬态时间12u；noisefmax 30GHz；noiseseed 1111； noisescale 1； noisefmin 100kHz；noisetmin____； multiplier tuns 2；这样不知道对不对。这样的设置仿真一次要5个小时，真是伤不起。
而且我昨天dft设置有点少了，频谱最大频率才1GHz，没有我想要的3GHz，所以也没看到闪烁噪声到底加进去没有，请指教下吧。

TiamoSYF · 发表于 2019-11-13 16:18:08

我想请问一下，如果不设置这个transient noise选项，是不是电路中就没有噪声影响了？

jjooee · 发表于 2020-4-3 16:14:50

terminal  input  command:: spectre -h tran

Transient noise parameters
79    trannoisemethod=default
                        use this option to enable the adaptive noise step
                        control. Possible values are default and adaptive.
80    noisefmax=0 Hz The bandwidth of pseudorandom noise sources. A valid
                        (nonzero) noisefmax turns on the noise sources during
                        transient analysis. The maximum time step of the
                        transient analysis is limited to 0.5/noisefmax.
81    noisescale=1    Noise scale factor applied to all generated noise.
                        Can be used to artificially inflate the small noise
                        to make it visible above transient analysis numerical
                        noise floor, but it should be small enough to
                        maintain the nonlinear operation of the circuit .
82    noiseseed       Seed for the random number generator. Should be
                        positive integer. Specifying the same seed allows you
                        to reproduce a previous experiment.
83    noisefmin (Hz) If specified, the power spectral density of the noise
                        sources depends on the frequency in the interval from
                        noisefmin to noisefmax. Below noisefmin, the noise
                        power density is constant. The default value is
                        noisefmax, so that only white noise is included by
                        default, and noise sources are evaluated only at
                        noisefmax for all models. 1/noisefmin cannot exceed
                        the requested time duration of transient analysis.
84    noisetmin (s)    Time interval between noise source updates. Default
                        is 0.5/noisefmax. Smaller values produce smoother
                        noise signals, but reduce time integration step.
85    noiseupdate=step  Forces evaluation of bias-dependent device noise
                        sources with noisetmin step (`fmax'), or at each time
                        step, even if it is smaller than noisetmin value
                        (`step'). Possible values are step and fmax.
86    origname
87    noiseon=[...]    The list of instances to be considered as noisy
                        during transient noise analysis.
88    noiseoff=[...] The list of instances to be considered as not noisy
                        during transient noise analysis.