N5161A/62A/81A/82A/83A MXG Signal Generators User's Guide

Basic Digital Operation (Option 651/652/654)Using the Equalization FilterUsing the Equalization FilterAn equalization FIR file can be created externally, uploaded via SCPI, and subsequently selected fromthe file system (refer to “Working with Files” on page 63). For information related to downloadingFIR file coefficients, refer to the Programming Guide. For information regarding working with FIRfile coefficients manually, refer to “Modifying a FIR Filter Using the FIR Table Editor” on page 213.This filter can be used to correct and/or impair the RF and External I/Q outputs for the internal I/Qsource. This filter will be convolved with the ACP Internal I/Q Channel Optimization filter if thatfilter is selected, the result of which will be truncated to the center 256 taps. The equalization filteroperates at 125MHz, so all equalization filters must be resampled to 125MHz prior to selection, ifthey are sampled at some other rate.The MXG supports equalization filters—either Complex or Real—that are programmable FIR filterswith two inputs (I, Q) and two outputs (I, Q) per sample. This 256- tap filter has two modes ofoperation:NOTEThe maximum number of taps is 256 (with 2 coefficients per tap for a complex filter) forequalization filters. The minimum number of taps is 2.Equalization filters can also be referred to as predistortion filters or correction filters.Type ofFilterRealComplexDescriptionThe I and Q samples are independently filtered by a single set of real coefficients.The samples are treated as complex (I + jQ) and convolved with the filter coefficients whichare specified as (I + jQ) in the time domain.The equalization filter can be turned on and off.Agilent N5161A/62A/81A/82A/83A MXG Signal Generators User’s Guide 205