关于Noise-Aware PLL的仿真

stoneduan · 发表于 2011-5-30 17:35:32

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本帖最后由 stoneduan 于 2011-5-30 17:42 编辑

Hi all
我在使用cadence的ppv模型仿真PLL的jitter，瞬态仿真完成后，PLL noise PSD输出如下图所示。
图中的period jitter是不是应该为long term的RMS period Jitter，而phase jitter我倒是没有看到有文章中提到。
有知道的么？

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stoneduan · 发表于 2011-5-30 21:28:01

这是图形，phase jitter什么意思？

PSD

stoneduan · 发表于 2011-5-31 09:50:49

本帖最后由 stoneduan 于 2011-5-31 09:52 编辑

原来phase jitter是phase noise在指定频率内的积分值
难道这两个仿真出来的值，一个是瞬态的jitter即deterministic jitter, 另一个是random jitter由noise造成的？

Phase Jitter – Phase Noise Integration.
For many communications applications, the total noise power over a specific range of frequencies – not the shape (as shown in figure 12) is the primary concern. In order to determine the power over the frequency range (bandwidth), the time domain signal must be analyzed in the frequency domain, and then reconstructed in the time domain into an rms value with the unwanted frequencies excluded. This may be done by converting L(f) back to Sϕ(f) over the bandwidth in question, integrating and performing some additional calculations. The result is an rms value for ϕ(t). The result may be expressed in dB, adians,
unit intervals, or seconds. The value, in seconds, represents 1 standard deviation of phase jitter contributed by the noise in the defined bandwidth. Figure 13 graphically displays the integrated area in green. The bandwidth for the integration in this example is 500 to 10000Hz..