Filter
Top Products
190 Agilent N5161A/62A/81A/82A/83A MXG Signal Generators User’s Guide
Basic Digital Operation (Option 651/652/654) Preliminary
I/Q Modulation Preliminary
I/Q Modulation
The following factors contribute to the error vector magnitude:
• Differences in amplitude, phase, and delay between the I and Q channels
•DC offsets
The I/Q menu not only enables you to select the I/Q signal source and output, it also provides
adjustments and calibrations to compensate for differences in the I and Q signals.
See also, “Modulating the Carrier Signal” on page 60.
Figure 8-15 I/Q Display and Softkeys
These selections are
reflected in the
I/Q Routing &
Optimization graphic.
page 193
This panel displays the current
settings for the I/Q signal routing
and I/Q correction optimized path.
This panel displays the current status and settings
of the I/Q adjustments. Use the Page Up and
PageDown keys to scroll through these
parameters. Grey indicates an inactive (off)
adjustment.
Used only with internally generated, bursted modulation
formats. Enables/disables the RF burst modulator.
For details on each key, use key help
as described on page 42.
Each path requires different optimization values;
when you select a path, you are selecting the
unique optimization values required by that path.
The signal generator applies the selected
optimization values to both paths, which impairs
the unselected path.
Inverts an internally generated Q signal, so that the I component lags the
Q component by 90 degrees.
Opens the internal I/Q Equalization Filter which can be used
to correct and/or impair the RF and External I/Q outputs for
the internal I/Q source.
Selects between optimizing the internal I/Q channel for EVM (in channel
performance) at the expense of ACP (out of channel performance) or
optimizing for ACP at the expense of EVM.
EVM is an 80% nyquist filter (100Mhz wide) with a wide transition band.
When an equalization filter is active, this filter is not active.
ACP is also an 80% nyquist filter (100Mhz wide), but the transition band
is very narrow, thus reducing images for wide-band signals. This filter will
be convolved with the active equalization filter, the result of which will be
truncated to the center 256 taps.
SCPI Commands:
[:SOURce]:DM:INTernal:CHANnel:OPTimization EVM|ACP
[:SOURce]:DM:INTernal:CHANnel:OPTimization?