Andrew Beckett
Senior Fellow
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Life, don't talk to me about Life...
Posts: 1742
Bracknell, UK
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Some of the confusion arises from the fact that there was some incorrect information in the SpectreRF documentation up to and including IC446, which suggested setting maxsidebands to 0. Some of this came about because in the spectreS interface in the past, setting maxsidebands to "none" (or something like that) in the UI, actually didn't set the maxsidebands parameter, allowing spectre to use its built-in default of 7, giving reasonably OK results for most circuits.
However, setting it to 0 makes no sense, because it means that you are only including the noise at the oscillator frequency itself, and not the upconverted noise around DC (mainly the flicker noise), and downconverted higher frequency noise. The lack of upconverted noise would be a major error in the noise output.
Andrew.
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