The Spectrum Application
R&S
®
FPC
109
User Manual 1178.4130.02 ─ 07
frequency of the video filter will be rejected. The smaller the video bandwidth, the
smaller the noise amplitude at the video filter output.
The video bandwidth (VBW) has several effects on measurements.
●
If you want to keep signals free of noise, you should select the smallest video
bandwidth possible (≤ 0.1 x RBW).
●
When you are measuring modulated signals, the video bandwidth must be suffi-
ciently large so that significant modulation components are not rejected (≥ RBW).
●
When you are measuring pulsed signals, the video bandwidth should be at least
three times higher than the resolution bandwidth so that the pulse edges are not
distorted.
Setting the video bandwidth
1. Press the "BW" key to open the bandwidth menu.
2. Select one of the "RBW: <x>" menu items.
● "VBW: Manual"
Opens an input field to select one of the available bandwidths.
If you enter a bandwidth that the R&S
FPC does not support, the R&S
FPC
rounds to the next available bandwidth. Refer to the data sheet for more infor-
mation on available resolution bandwidths
A manually selected VBW is indicated by a blue dot in front of the "VBW" label
in the status bar.
Figure 14-12: Indicator of manual video bandwidth
● "VBW: Auto"
Automatically selects an appropriate video bandwidth depending on the current
resolution bandwidth.
3. Enter the required video bandwidth.
The R&S
FPC uses the video bandwidth you have entered for the measurement.
14.6
Sweep Configuration
Access
: "Sweep"
Remote commands to control the sweep:
●
Chapter 19.12.5, "Sweep Control"
"Sweep" is another word for the measurement process of the spectrum analyzer (tradi-
tional spectrum analyzers have a tunable local oscillator that "sweeps" across the fre-
quency spectrum to determine the frequency characteristics of the applied signal).
Sweep Configuration
