Fast Fourier Transforms
TDS 620A, 640A & 644A User Manual 3Ć43
Zero Phase
Reference
%! ! >
%! ! ≤
FFT Time Domain Record =
Waveform Record
Zero Phase
Reference
FFTTime Domain Record = 10k
Figure 3Ć24:ăWaveform Record vs. FFT Time Domain Record
FFTs TransformTime Records to Frequency Records)
# !! $"# "! " $# ! # $! ( "&"
# #!"!# ## # # !! # ! $'
!! !"$# ! $' !! " # #
# $# $" # $#" # "#% #%
! $" # #% %$" !!! # "#% %$" ' #
"#% %$" ! "'
!
! $' !
FFT
Figure 3Ć25:ăFFT Time Domain Record vs. FFT Frequency Domain
Record
FFT Frequency Range and Resolution) '$ #$!
&%! # "" "'" #! # #$ ! "
# ! $' !! !"$# #& # "!#
! $" "' #" &%! " #! ' # & $(
#