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Keysight EXG and MXG X-Series Signal Generators User’s Guide
Basic Digital Operation (Option 653/655/656/657)
Using the Equalization Filter
Using the Equalization Filter
An equalization FIR file can be created externally, uploaded via SCPI, and subsequently selected
from the file system (refer to
“Working with Files” on page 56
). For information related to
downloading FIR file coefficients, refer to the
Programming Guide
. For information regarding
working with FIR file coefficients manually, refer to
“Modifying a FIR Filter Using the FIR Table
.
This filter can be used to correct and/or impair the RF and External I/Q outputs for the internal I/Q
source. This filter will be convolved with the ACP Internal I/Q Channel Optimization filter if that filter
is selected, the result of which will be truncated to the center 256 taps. The equalization filter
operates at 200 MHz, so all equalization filters must be resampled to 200 MHz prior to selection, if
they are sampled at some other rate.
The MXG/EXG supports equalization filters—either Complex or Real—that are programmable FIR
filters with two inputs (I, Q) and two outputs (I, Q) per sample. This 256-tap filter has two modes of
operation:
The equalization filter can be turned on and off.
The maximum number of taps is 256 (with 2 coefficients per tap for a
complex filter) for equalization filters. The minimum number of taps is 2.
Equalization filters can also be referred to as predistortion filters or
correction filters.
Type of Filter
Description
Real
The I and Q samples are independently filtered by a single set of real coefficients.
Complex
The samples are treated as complex (I + jQ) and convolved with the filter coefficients which are
specified as (I + jQ) in the time domain.
