User Manual

Analog Demodulation
R&S
®
FPC
143User Manual 1178.4130.02 ─ 05
Shows the total harmonic distortion.
The THD is the ratio of the harmonics to the fundamental and harmonics. All har-
monics inside AF spectrum are considered up to the tenth harmonic.
14.2 Frequency Configuration
Access: "Freq"
Access: "Setup" > "Config Overview" > "Frequency" (selected settings)
Remote commands to configure the frequency:
●
Chapter 17.14.2, "Frequency", on page 291
The R&S FPC can demodulate a signal only if the frequency of the carrier signal is
known. Therefore, you have to define the frequency of the carrier signal, before any
useful information about the signal is shown in the application.
The width of the captured signal (the "span") is defined by the demodulation band-
width.
If you do not know the frequency of the carrier signal, you have to find it out. You can
do that, for example, by searching the frequency spectrum in the spectrum application
in the area where you assume that the carrier is located.
Frequency settings in the analog modulation application described elsewhere:
●
"Center Frequency": "Defining a center frequency" on page 89
●
"Frequency Step Size": "Defining a frequency step size" on page 89
14.3 Amplitude Configuration
Access: "Ampt"
Access: "Setup" > "Config Overview" > "Amplitude" (selected settings)
Remote commands to configure the amplitude:
●
Chapter 17.12.3, "Amplitude", on page 241
Amplitude settings in the analog modulation application described elsewhere:
●
"Reference Level": Chapter 12.4.1, "Reference Level", on page 94
●
"Preamplifier": "Preamplifier" on page 98
●
"Attenuator": "RF attenuator" on page 96
●
"Impedance": "Selecting the input impedance" on page 93
When you select the graphical result display, you can also adjust the scale of the y-
axis.
Amplitude Configuration