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Keysight InfiniiVision 3000T X-Series Oscilloscopes User's Guide
4
FFT Spectral Analysis
Aliasing happens when there are frequency components in the signal higher than
half the sample rate. Because the FFT spectrum is limited by this frequency, any
higher components are displayed at a lower (aliased) frequency.
The following figure illustrates aliasing. This is the spectrum of a 990 Hz square
wave, which has many harmonics. The horizontal time/div setting for the square
wave sets the sample rate and results in a FFT resolution of 1.91 Hz. The displayed
FFT spectrum waveform shows the components of the input signal above the
Nyquist frequency to be mirrored (aliased) on the display and reflected off the right
edge.
Because the frequency span goes from
≈
0 to the Nyquist frequency, the best way
to prevent aliasing is to make sure that the frequency span is greater than the
frequencies of significant energy present in the input signal.
Figure 5
Aliasing
Содержание DSOX3012T
Страница 78: ...78 Keysight InfiniiVision 3000T X Series Oscilloscopes User s Guide 2 Horizontal Controls...
Страница 88: ...88 Keysight InfiniiVision 3000T X Series Oscilloscopes User s Guide 3 Vertical Controls...
Страница 98: ...98 Keysight InfiniiVision 3000T X Series Oscilloscopes User s Guide 4 FFT Spectral Analysis...
Страница 148: ...148 Keysight InfiniiVision 3000T X Series Oscilloscopes User s Guide 7 Digital Channels...
Страница 154: ...154 Keysight InfiniiVision 3000T X Series Oscilloscopes User s Guide 8 Serial Decode...
Страница 160: ...160 Keysight InfiniiVision 3000T X Series Oscilloscopes User s Guide 9 Display Settings...
Страница 232: ...232 Keysight InfiniiVision 3000T X Series Oscilloscopes User s Guide 13 Acquisition Control...
Страница 242: ...242 Keysight InfiniiVision 3000T X Series Oscilloscopes User s Guide 14 Cursors...
Страница 288: ...288 Keysight InfiniiVision 3000T X Series Oscilloscopes User s Guide 16 Mask Testing...
Страница 294: ...294 Keysight InfiniiVision 3000T X Series Oscilloscopes User s Guide 17 Digital Voltmeter and Counter...
Страница 300: ...300 Keysight InfiniiVision 3000T X Series Oscilloscopes User s Guide 18 Frequency Response Analysis...
Страница 320: ...320 Keysight InfiniiVision 3000T X Series Oscilloscopes User s Guide 19 Waveform Generator...
Страница 340: ...340 Keysight InfiniiVision 3000T X Series Oscilloscopes User s Guide 21 Print Screens...
Страница 374: ...374 Keysight InfiniiVision 3000T X Series Oscilloscopes User s Guide 23 Web Interface...
Страница 394: ...394 Keysight InfiniiVision 3000T X Series Oscilloscopes User s Guide 24 Reference...
Страница 416: ...416 Keysight InfiniiVision 3000T X Series Oscilloscopes User s Guide 25 CAN LIN Triggering and Serial Decode...
Страница 426: ...426 Keysight InfiniiVision 3000T X Series Oscilloscopes User s Guide 26 CXPI Triggering and Serial Decode...
Страница 436: ...436 Keysight InfiniiVision 3000T X Series Oscilloscopes User s Guide 27 FlexRay Triggering and Serial Decode...
Страница 480: ...480 Keysight InfiniiVision 3000T X Series Oscilloscopes User s Guide 30 Manchester NRZ Triggering and Serial Decode...
Страница 510: ...510 Keysight InfiniiVision 3000T X Series Oscilloscopes User s Guide 32 SENT Triggering and Serial Decode...
Страница 520: ...520 Keysight InfiniiVision 3000T X Series Oscilloscopes User s Guide 33 UART RS232 Triggering and Serial Decode...