Keysight N9038A Service Guide

Keysight N9038A MXE Service Guide 393
Optional Assemblies
A26 Wideband Digital IF Assembly Description
A26 Wideband Digital IF Assembly Description
A26 Wideband Digital IF Assembly Purpose
The primary role of the A26 Wideband Digital IF assembly is to accept samples
from the ADC on the A25 Wideband Analog IF assembly and perform Digital
Signal Processor operations on them before either saving them to local
memory or host memory. This assembly communicates with and is controlled
by the A4 Processor assembly via the instrument 32 bit 33 MHz PCI Bus.
A26 Wideband Digital IF Assembly Description
The signal flow through the A26 Wideband Digital IF assembly begins as the
ADC samples from the A25 Wideband Analog IF assembly flow into the FPGA.
The FPGA can be programmed to route the samples various ways, but the
typical setup is that they next flow into the DSP ASIC for processing, and then
back into the FPGA where they are processed further before being routed
either to the local DDR-2 SDRAM or a PCI bus target such as the Power PC or
the A4 Processor assembly.
DSP ASIC
The DSP ASIC provides high speed real-time DSP functionality at sample rates
of up to 300 MSmp/s DDR. The ADC samples are routed through the DPS ASIC
to allow real-time amplitude and phase corrections, complex
down-conversion, arbitrary resampling and decimation, channel filtering, and
detection. The input filter is used to correct both for the amplitude and phase
characteristics of the instrument. It also does the complex conversion to
baseband. The output filter can be used to provide arbitrary channel filters
such as Root-Raised Cosine, or Gaussian. The detectors are capable of
delivering results as I and Q, magnitude and phase, log of magnitude and
phase, and magnitude squared.
FPGA
The FPGA includes the ADC data input as well as interfaces to the DSP ASIC,
the 2 GByte DDR-2 SDRAM memory, the PCI bus, and the CPLD. It also
provides signal routing, and additional functions such as hardware averaging,
data packing.
The FPGA is programmed both at power up as well as on the fly whenever the
behavior of the signal processing needs to be altered. Multiple images used for
programming the FPGA are stored locally in flash and can be swapped by the
Power PC in 20 msec.
Refer to Chapter 15, “Block Diagrams”

Keysight N9038A Specifications

General

Brand	Keysight
Model	N9038A
Category	Measuring Instruments
Language	English