Filter
Top Products
126 Chapter 6
Custom Arb Waveform Generator
Working with Filters
• Filter Alpha enables you to adjust the filter alpha for a Nyquist or root Nyquist filter. If a Gaussian filter is
used, you will see Filter BbT; this softkey is grayed out when any other filter is selected.
•(Custom Realtime I/Q Baseband Only) Optimize FIR for EVM ACP enables you to optimize a Nyquist
or root Nyquist filter for minimized error vector magnitude (EVM) or for minimized adjacent channel
power (ACP); the softkey is grayed out when any other filter is selected.
•
Restore Default Filters replaces the current FIR filter with the default FIR filter for the selected format.
Using a Predefined FIR Filter
Selecting a Predefined FIR Filter
1. Preset the instrument: Press
Preset.
2. Press
Mode > Custom > ARB Waveform Generator > Digital Mod Define > Filter > Select
or
Mode > Custom > Real Time I/Q Baseband > Filter > Select >
3. Select the desired filter. If the filter you want is not in the first list, press
More (1 of 2).
Adjusting the Filter Alpha of a Predefined Root Nyquist or Nyquist Filter
1. Preset the instrument: Press
Preset.
2. Press
Mode > Custom > ARB Waveform Generator > Digital Mod Define > Filter > Filter Alpha
or
Mode > Custom > Real Time I/Q Baseband > Filter > Filter Alpha
3. Enter a new Filter Alpha value and press Enter.
Adjusting the Bandwidth-Bit-Time (BbT) Product of a Predefined Gaussian Filter
1. Press
Mode > Custom > ARB Waveform Generator > Digital Mod Define > Filter > Select > Gaussian
or
Mode > Custom > Real Time I/Q Baseband > Filter > Select > Gaussian
2. Press Filter BbT.
3. Enter a new Bandwidth-Bit-Time (BbT) product filter parameter and press
Enter.
Optimizing a Nyquist or Root Nyquist FIR Filter for EVM or ACP (Custom Realtime I/Q Baseband only)
1. Preset the instrument: Press
Preset.
2. Press
Mode > Custom > Real Time I/Q Baseband > Filter > Optimize FIR For EVM or ACP.
The FIR filter is now optimized for minimum error vector magnitude (EVM) or for minimum adjacent
channel power (ACP). This feature applies only to Nyquist and root Nyquist filters; the softkey is grayed
out when any other filter is selected.