Introduction - Anritsu MS2024A/MS2026A User Manual

Chapter 9 — Interference
Analyzer, Option 25

9-1 Introduction

Many wireless networks operate in complicated signal environments. Three or four base
station antennas may be located onto the same tower and can create interference problems,
which can affect system capacity and coverage.
The Interference Analyzer option adds three measurement capabilities to the VNA Master:
• Spectrogram
• Signal Strength
• RSSI (Received Signal Strength Indicator)
The instrument also has a spectrum mode which displays signals in a traditional Spectrum
Analyzer view.
The following menus are available in Interference Analyzer (Option 25) mode.
9-2 Spectrogram Measurement
A Spectrogram is a three dimensional representation of frequency, time and power useful for
identifying intermittent interference. Color is used to represent power levels.
shows a sample spectrogram display in a Field measurement menu.
Procedure
The following procedure demonstrates one example of an Interference Analyzer Spectrogram
setup.
1. Select the
Shift
select
Interference Analyzer
2. Press the
Freq
3. Select the
Signal Standard
dialog box displayed. Alternatively, choose the appropriate soft keys and enter the
center, start and stop frequencies and the span.
4. For the most effective spectrogram display, press the
soft key and set the reference level such that the largest signal to be displayed will
Level
be near the top of the Spectrum Analyzer area of the screen. The reference value
required can be determined by observing the color of the highest signal and changing
the reference level to place that value near the top of the Spectrum Analyzer area.
5. Select the
Scale
bottom of the screen. In general, 4 or 5 dB/division will be good starting values.
6. Select the
BW
RBW and VBW values by selecting the
MS20xxA VNA Master UG 10580-00166 Rev. C
key, then the
Mode
and press the
function hard key.
soft key and select the desired air interface standard from the
soft key and set the scale value to place the lowest signal near the
function hard key and set
(9) key, using rotary knob or Up/Down arrow keys
key to select.
Enter
Amplitude
and
Auto RBW Auto VBW
and
RBW VBW
Figure 9-1
key, select the
On, or set the applicable
soft keys.
Reference
9-1