FFT Analyzer Basic FAQ

In typical FFT processing, the storage of digital data into buffer memory and the FFT calculation are performed in parallel. In spectral averaging, when the FFT processing time is smaller than the FFT time window length T, that is, when the FFT calculation is performed without missing any instantaneous time-series data, it is called real-time analysis, and the frequency range at which this is possible (the best possible) is called the real-time frequency range.

Using the DS-2104A analyzer as an example, when performing 800-line analysis in a 40 kHz range, the time window length is 20 ms. The DS-2104A analyzer processes 4-channel spectral averaging in approximately 20 ms, so the real-time frequency range is 40 kHz (4 channels, 800 lines).

	Real-time analysis (FFT basic terminology glossary)