Digital Demodulation
R&S
®
FPC
167
User Manual 1178.4130.02 ─ 07
If you do not know the frequency of the carrier signal, you have to find it out, for exam-
ple by searching the frequency spectrum in the spectrum application in the area where
you assume that the carrier is located.
Frequency settings in the digital modulation application described elsewhere:
●
"Center Frequency":
●
"Frequency Step Size":
"Defining a frequency step size"
●
"Frequency Offset":
17.4
Amplitude Configuration
Access
: "Ampt"
Access
: "Setup" > "Config Overview" > "Amplitude" (selected settings)
Access
: "Setup" > "Config Overview" > "Input" (selected settings)
Remote commands to configure the amplitude:
●
Amplitude settings in the digital modulation application described elsewhere:
●
"Reference Level":
Chapter 14.4.1, "Reference Level"
●
"Preamplifier":
●
"Attenuator":
●
"Impedance":
"Selecting the input impedance"
When you select one of the graphical result displays, you can also adjust the scale of
the y-axis.
Defining the position of the reference (ASK signals)
In the graphical result displays, you can define the reference position on the y-axis.
The reference corresponds to the top of the grid (100 % by default). You can change
the reference to another percentage, for example to see the signal in more detail.
1. Press the "Ampt" key to open the amplitude menu.
2. Select the "Ref Position" menu item.
The R&S
FPC opens an input field to define the reference position.
3. Enter the percentage that should be displayed at the top of the diagram.
The R&S
FPC adjusts the y-axis and the position of the trace accordingly.
Adjusting the scale of the y-axis
For both ASK and FSK measurements, you can adjust the display range of the y-axis.
The display range is defined in terms of values covered by a grid division. This value
multiplied by 10 is the whole display range.
1. Press the "Ampt" key to open the amplitude menu.
Amplitude Configuration
