N5161A/62A/81A/82A/83A MXG Signal Generators User's Guide

Basic Digital Operation (Option 651/652/654)Using Finite Impulse Response (FIR) Filters in the Dual ARB Real-Time Modulation FilterCreating a User–Defined FIR Filter Using the FIR Table EditorIn this procedure, you use the FIR Values table editor to create and store an 8–symbol, windowedsync function filter with an oversample ratio of 4.Accessing the Table Editor1. Press Preset.2. Press Mode > Dual ARB > Arb Setup > More > Real-Time Modulation Filter > Select > Nyquist.3. Press Define User FIR.4. Press More 1 of 2 > Delete All Rows > Confirm Delete of All Rows.This will initialize the table editor as shown in Figure 8- 18.Figure 8-18 Creating a User–Defined FIR Filter Using the FIR Filter Table EditorMode > Dual ARB > Arb Setup > More > Real-Time Modulation Filter > Define For details on each key, use key help as described on page 42.User FIR > More 1 of 2 > Delete All Rows > Confirm Delete of All RowsOpens a menu thatenables you to selectand load a saved fileinto volatile memory.See page 43.page 214Adds a column forspecifying the imaginarycoefficients of the filter.*(All of the imaginarycoefficients will be 0initially.) If the Convert toComplex Filter softkeyhas been selected theConvert to Real Filtersoftkey becomesavailable.Caution: Selecting theConvert to Real Filtersoftkey removes theImaginary Values columnand the imaginary valuesare lost.Note:Modulation filters must be real and have an oversample ratio (OSR) of 2 or greater.Equalization filers are typically complex and must have an oversample ratio (OSR) of 1.Active only when:FIR filter coefficient tablehas minimum of twovalues visible.Entering the Coefficient Values1. 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 0.208 Agilent N5161A/62A/81A/82A/83A MXG Signal Generators User’s Guide