Advantest R3131A Spectrum Analyzer

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Advantest R3131A Spectrum Analyzer
Quick Reference Guide
Main Controls
The first three buttons listed below are the most
often used. Many buttons bring up a softkey
menu to the right of the screen. Numeric values
are entered using the keypad and units buttons to
the left of the dial.

• PRESET (hit blue shift key first). This restores
  the analyzer to a known state. This is a good
  place to start.
• FREQ Use to set the start and stop points of the
  sweep, or to specify a center frequency (and then
  use SPAN).
• SPAN Allows easy setup for narrowband signal
  observations. (After setting a center frequency).
• LEVEL Sets the reference level (max power at top
  of scale) in dBm. Also allows modifying dB/div
  or switching to linear scale.
• BW Allows you to set the resolution bandwidth
  (RBW) and video bandwidth (VBW). A narrow RBW
  helps make sure you are seeing the signals real
  spectrum and not the shape of the internal
  filter!
• PK SRCH Searches for the peak of the displayed
  spectrum. Useful to turn on the marker and get a
  quick measurement.
• MKR-gt Useful following PK SRCH to recenter the
  signal in the display prior to zooming-in by
  decreasing the span.
• COPY Use in conjunction with the floppy drive to
  record the display for use in reports.

Overview

• The spectrum analyzer is a special type of radio
  receiver designed to sweep through a range of
  frequencies, measure the amplitude at each point,
  and display the results.
• Usually the amplitudes are displayed in terms of
  power in dBm (dB relative to a milliwatt), with
  a 10dB/div scale. The top line on the display is
  called the reference level and defaults to 0 dBm
  (1 mW). See screen above.
• Even with no signal, the background noise power
  can still be seen. It is typically 70 or more dB
  below the reference level (-70 dBm 0.1 nW)
  depending on the resolution bandwidth in use and
  the analyzer sensitivity.

Block Diagram
Rev 1.0, 02 July 2006, WBK