YASKAWA AQ6370B - Page 321

App-9
IM 735302-01E
Appendix
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App
Index
NOTCH Width Measurement
Obtain a bottom level. Then, obtain the NOTCH width for the bottom level and its center
wavelength.
Following table shows the details of parameters for NOTCH analyses.
Parameter Abbreviation Default Value Setting Range Unit Description
THRESH TH 3.00 0.01 to 50.00 dB Threshold value
K K 1.00 1.00 to 10.00 - Multiplying factor
TYPE TYPE BOTTOM BOTTOM / PEAK - Reference position for
search
Algorithms for analyses are described here. They differ depending on the types of
analysis (BOTTOM/PEAK). Algorithms for each type of analysis are described below.
When “TYPE” is BOTTOM
λ
A
λ
C
λ
B
λ
min
LGmin+TH
LGmin
• Obtaintheminimumlevel“LGmin.”Also,setthewavelengthofthispointtoλmin.
• Set the rightmost wavelength, which is located on the left of
λ
min and which crosses
the level (LOG) of |LGmin + threshold value (THRESH[dB])|, to
λ
A.
• Settheleftmostwavelength,whichislocatedontherightofλminandwhichcrosses
the level (LOG) of |LGmin + threshold value (THRESH[dB])|, to
λ
B.
• Obtain
λ
A and
λ
B through multiplication by the value which is set to the multiplying
factor K.
λ
'C = (
λ
B +
λ
A)/2
λ
A = K × (
λ
A -
λ
'C) +
λ
'C
λ
B = K × (
λ
B -
λ
'C) +
λ
'C
• Obtain the NOTCH width from the following equation.
Δλ
=
λ
A -
λ
B
• Obtain the center wavelength
λ
C from the following equation.
λ
C = (
λ
A +
λ
B)/2
Appendix 2 Data Calculation Algorithms for Spectrum Widths