Rohde & Schwarz FPC1000, User Manual

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The Spectrum Application
FPC1000
103
User Manual 1178.4130.02 ─ 02
9.10 Marker Functions
Access
: "Mkr"
Remote commands required to control marker functions:
●
Chapter 13.10.8, "Marker" , on page 208
Marker functions are measurements that you can perform with markers. Depending on
the marker function you have selected, the R&S FPC1000 measures certain signal
characteristics on the marker position.
The marker functions are applied to the currently selected marker.
Deactivating marker functions
Selecting a marker function again while it is still active turns that marker function off.
● Noise Measurement ..............................................................................................103
● Frequency Counter ............................................................................................... 104
● Signal Bandwidth Measurement ........................................................................... 104
● Marker Demodulation ............................................................................................105
9.10.1 Noise Measurement
Access
: "Mkr" > "Marker Mode" > "Noise"
The marker noise measurement calculates the noise power density at the marker posi-
tion in dBm/Hz. The R&S FPC1000 includes several variables in the calculation of the
noise power density, including the trace pixel values, the resolution bandwidth, the
detector and the level display mode (absolute or relative). To stabilize the noise power
display, the R&S FPC1000 uses the pixel the marker is on and four pixels to the right
and four pixels to the left of the marker pixel.
Noise power density can provide useful information when you are measuring noise or
digitally modulated signals. However, you will get valid results only if the spectrum in
the vicinity of the marker has a flat frequency response. When measuring the noise
power density on discrete signals, results are not valid.
Note that the noise measurement only works for marker 1 (M1) or delta marker 2 (D2).
Measuring the noise density
1. Press the "Mkr" key to open the marker menu.
2. Select the "Marker Mode" menu item to open the marker function menu.
3. Select the "Noise" menu item.
The R&S FPC1000 shows the noise density at the marker frequency in the marker
list in dBm/Hz. If you are using a delta marker for the measurement, the results
have the unit dBc/Hz with marker
1 being the reference. This is useful for phase
noise measurements, for example.
Marker Functions
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