Hi, hat jemand den Begriff „gated FFT“ im Spektrumanalyser gehört? Diese folgende Beschreibung stammt aus Keysight: The Keysight X-Series signal analyzers have built-in FFT capabilities. In this mode, the data is acquired for an FFT starting at a chosen delay following a trigger. The IF signal is digitized and captured for a time period of 1.83 divided by resolution bandwidth. An FFT is computed based on this data acquisition and the results are displayed as the spectrum. Thus, the spectrum is that which existed at a particular time of known duration. This is the fastest gating technique when the span is not wider than the FFT maximum width. To get the maximum possible frequency resolution, choose the narrowest available RBW with a capture time that fits within the time period of interest. You may not always need that much resolution, however, and you could choose a wider RBW with a corresponding narrower gate length. The minimum usable RBW in gated FFT applications is always lower than the minimum usable RBW in other gating techniques, because the IF must fully settle during the burst in other techniques, which takes longer than 1.83 divided by RBW. Angehängt ist eine Folie über gated FFT, ebenfalls aus Keysight. Das Problem ist, ich kann die beiden leider nicht miteinander zusammenhängen. Also kann mir jemand etwa aufklären? Senmeis
Angehängte Dateien:
-
gated_fft.jpg
(120 KB)
