Keysight E8663D, Руководство пользователя

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196 Keysight E8357D/67D & E8663D PSG User’s Guide
Custom Arb Waveform Generator
Working with Filters
6. Use the numeric keypad to type the first value (
-
0.000076) from the
following table and press Enter . As you press the numeric keys, the
numbers are displayed in the active entry area. (If you make a mistake, you
can correct it using the backspace key.) Continue entering the coefficient
values from the table until all 16 values have been entered.
7. Press Mirror Table .
In a windowed sinc function filter, the second half of the coefficients are
identical to the first half, but in reverse order. The signal generator
provides a mirror table function that automatically duplicates the existing
coefficient values in the reverse order; coefficients 16 through 31 are
automatically generated and the first of these coefficients (number 16)
highlights, as shown in the following figure.
8. For this example, the desired OSR is 4, which is the default, so no action is
necessary.
The Oversample Ratio (OSR) is the number of filter coefficients per
symbol. Acceptable values range from 1 through 32; the maximum
combination of symbols and oversampling ratio allowed by the FIR Values
editor is 1024. Remember, however, that the instrument hardware is
Table 6-1
Coefficient Value Coefficient Value Coefficient Value
0 -
0.000076
6 0.043940 12 0.123414
1
-
0.001747
7 0.025852 13 0.442748
2 -
0.005144
8 -
0.035667
14 0.767329
3
-
0.004424
9
-
0.116753
15 0.972149
4 0.007745 10 -
0.157348
5 0.029610 11
-
0.088484