Filter
Top Products
Agilent N5161A/62A/81A/82A/83A MXG Signal Generators User’s Guide 209
Preliminary Basic Digital Operation (Option 651/652/654)
Preliminary Multiple Baseband Generator Synchronization
Common uses for the real-time modulation feature include:
• Where the single carrier rectangular ideal I/Q symbol decision points are known and are to have
an over-sampled filter applied.
• Where greater effective MXG memory size is required.
• When you have a low rate waveform that could benefit from a higher OSR that does not make the
waveform longer.
The real-time modulation filter setup is one of the file header parameters (page 141), which means
you can store this setup with the waveform. When you select a waveform with a stored modulation
filter setup, the signal generator changes the current setup to match the stored file header setup. If
there is no stored modulation filter setup for the current waveform, the signal generator uses the last
set modulation filter setup.
You can also use the Save function (page 70) to store this value as part of the signal generator setup.
When you Recall a setup stored with the Save function, the modulation filter value becomes the
current instrument setting value, disregarding the stored file header value.
Use the following steps to apply a real-time modulation filter to the current waveform loaded into
volatile memory. This example uses the factory supplied waveform, SINE_TEST_WFM available in the
Dual ARB Player. To view the output for this example, connect the RF OUTPUT of the signal
generator to the input of a spectrum analyzer.
NOTE The following setup assumes you have completed the setup in “Setting the Baseband
Frequency Offset” on page 186 for creating a modulated RF signal that is offset from the
carrier frequency by 20 MHz.
1. Configure the modulation filter:
Press Mode > Dual ARB > Arb setup > More > Real-Time Modulation Filter > Select > Root Nyquist
2. Press Filter Alpha > .4 > Enter.
The modulated RF signal now has a real-time modulation filter of type root nyquist, with a filter
alpha of 0.400.
Multiple Baseband Generator Synchronization
Available in the Dual ARB menu, this feature lets you set up a master/slave system of up to sixteen
Agilent MXGs so that the baseband generators (BBG) synchronize the playing of waveforms. The
system count includes one Agilent MXG to function as the master (see “Equipment Setup” on
page 213).
The MXG with Option 012, enables 2x2, 3x3, or 4x4 MIMO configurations to share a common external
LO signal to create phase coherent system. Refer to “Understanding Option 012 (LO In/Out for Phase
Coherency) with Multiple Baseband Generator Synchronization” on page 216 and the Data Sheet.