Setting The Real-Time Modulation Filter - Agilent Technologies X Series User Manual

Basic Digital Operation (Option 653/655/656/657)

Setting the Real-Time Modulation Filter

Setting the Real-Time Modulation Filter
The real- time modulation filter effectively compresses a single carrier I/Q waveform down to just the
I/Q constellation points and then controls the transitions similar to the modulation filter in Arb
Custom modulation. The key difference is that this filter is applied as the waveform plays, rather
than in the waveform data itself. The real- time modulation filter is only available for Dual ARB
waveforms.
When the real- time modulation filter is on, the sample clock rate acts as the symbol rate. The sample
clock rate must be set to one half of the sample rate for the real- time Arb modulation filter feature
to be turned on. The sample rate is determined by the Option 65x baseband generator.
CAUTION Because the Arb format only supports rectangular I/Q data for defining the symbol
decision points, constant envelope modulation, which should be specified as magnitude
and phase, are not supported. (Examples of constant envelope modulation are MSK and
FSK.)
The carrier frequency must be the same for all frequencies used (i.e. only single carrier
applications work with arb real- time modulation filters).
Figure 8-26 Real-Time Modulation Filter Softkeys for the Dual ARB Player
Mode > Dual ARB > Arb
Setup > More
For details on each key, use key help
as described on page 44.
224
The settings in this menu
can be stored to the file
header, see page 155.
page 214
These are the available
real-time modulation filters that
can be applied to a waveform.
Agilent X-Series Signal Generators User's Guide