Agilent Technologies E4428C, User Manual, Page: 198 / 700

174 Chapter 4
Basic Digital Operation
Using Finite Impulse Response (FIR) Filters
Entering the Coefficient Values
1. Press the
Return
softkey to get to the first page of the table editor.
2. Use the cursor to highlight the
Value
field for coefficient 0, then press
Edit Item
.
3. Use the numeric keypad to type the first value (
−
0.000076) from Table 4-2 . 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.)
4. Continue entering the coefficient values from the table in step 1 until all 16 values have been entered.
Duplicating the First 16 Coefficients Using Mirror Table
In a windowed sinc function filter, the second half of the coefficients are identical to the first half in reverse
order. The signal generator provides a mirror table function that automatically duplicates the existing
coefficient values in the reverse order.
1. Press
Mirror Table
. The last 16 coefficients (16 through 31) are automatically generated and the first of
these coefficients (number 16) highlights, as shown in Figure 4-30 on page 175 .
Table 4-2
Coefficient Value Coefficient Value
0
−
0.000076 8
−
0.035667
1
−
0.001747 9
−
0.116753
2
−
0.005144 10
−
0.157348
3
−
0.004424 11
−
0.088484
4 0.007745 12 0.123414
5 0.029610 13 0.442748
6 0.043940 14 0.767329
7 0.025852 15 0.972149