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EV10AQ190x-DK - User Guide 4-33
1067BX–BDC–12/11
FFT Processing:
For future calculations, we define:
with: setup_PeakWidth = 1 = width of one spur given in number of points;
setup_cal_NbrOfHarmonics = 5 or 10 = number of harmonics used for the spectral cal-
culations
PmaxSpur = Power of the highest spur excluding the continuous component and the
fundamental
Sig = Signal power level ""spectrum
i
2
0
N

=
Ho = Power of the continuous component spectrum
i
2
0
setup.PeakWidth

=
H1 = Power of the fundamental spectrum
i
2
j
setup.PeakWidth

=
Hi = Power of the harmonics spectrum
i
2
j
""setup.PeakWidth

Harmonics
setup.cal..Nbr of Harmonics

=
= spectrum
i
2
j
setup.PeakWidth

SFSR
dBc
H1
dB
=
Average Noise
rms
Sig H0– H1–
N
sig
N
H0
– N
H1
–
--------------------------------------------- -= N = number of points
THD
dBc
10 log
H1i
H1
-------- -
=
SNR
dBc
10 log
H1
Sig H0– H1– H1i–
-------------------------------------------------- -
=
SFDR
dBc
20 log
Harmonic
rms
fundamental
rms
----------------------------------------- -
=
SINAD
dBc
10 log
Sig H0– Average Noise
2
rms
–
Sig H0– H1–
--------------------------------------------------------------------------------
=
ENOB
SINAD
dB
10 log 1.5–
6.02
---------------------------------------------------------
=
THD
dBFS
THD
dBc
SFSR
dBc
+=
SNR
dBFS
SNR
dBc
SFSR
dBc
–=
SFDR
dBFS
SFDR
dBc
SFSR
dBc
+=