![Rohde & Schwarz FPC Series User Manual Download Page 85](http://html.mh-extra.com/html/rohde-and-schwarz/fpc-series/fpc-series_user-manual_1477824085.webp)
The Spectrum Application
R&S
®
FPC
82
User Manual 1178.4130.02 ─ 07
Only the signal to be measured should be visible in the diagram. An additional sig-
nal would falsify the measurement.
●
Define a sufficient
.
The resolution bandwidth should be between 1
% and 4
% of the channel band-
width. This ensures that the occupied bandwidth is measured with high accuracy.
●
Define a sufficient
.
The video bandwidth must be at least three times the resolution bandwidth. This
prevents incorrect results due to the compression of signal peaks by the video fil-
ter.
●
.This ensures that the power measurement is always cor-
rect irrespective of the waveform being investigated.
Some of the measurement specifications (for example PDC, RCR STD-27B)
require measurement of the occupied bandwidth with a peak detector. The detector
setting has to be changed accordingly in those cases.
●
Select a sufficient
14.2.6.2
Configuration
Access
: "Meas"
The occupied bandwidth measurement supports several settings exclusive to that
measurement. These are available in the measurement menu.
Defining the percentage of the occupied bandwidth
The default power percentage to be evaluated inside the occupied bandwidth is 99
%,
a value most standards require. If your measurement requires a different power per-
centage, you can change that value.
1. Press the "Meas" key to open the measurement menu.
2. Select the "% Power Bandwidth" menu item.
The R&S
FPC opens an input field to define the power percentage.
3. Enter the power percentage the measurement requires.
The R&S
FPC now displays the occupied bandwidth graphically in the trace win-
dow and numerically above the trace window.
Note:
The value you enter here is the power percentage that has to be inside the
channel bandwidth relative to the power over the total span (the percentage of the
total power).
Defining the channel bandwidth
The channel bandwidth is the bandwidth of the signal that you are measuring.
Note that the R&S
FPC always selects a
that equals the channel band-
width
1. Press the "Meas" key to open the measurement menu.
2. Select the "Chan Bandwidth" menu item.
Measurements and Result Displays