3Phase Noise Measurement - Rohde & Schwarz R&S FSP Series Operating Manual

R&S FSP
In time domain mode, the measured values are averaged versus time (after a
sweep).
Remote command:
Example: Measurement of inherent R&S FSP noise
[PRESET]
[MARKER]
[NOISE]
The R&S FSP noise figure can be calculated from the measured power density
level. It is calculated by subtracting the set RF attenuation (RF Att) from the dis-
played noise level. 174 is to be added to the result to obtain the R&S FSP noise
figure.
4.5.11.3 Phase Noise Measurement
PHASE NOISE
PH NOISE (ON OFF)
REF POINT LEVEL
REF POINT LVL OFFSET
REF POINT FREQUENCY
PEAK SEARCH
AUTO PEAK SEARCH
The PHASE NOISE softkey switches the PHASE NOISE function on/off. Addition-
ally, the softkey opens the submenu for manually setting the reference point. The
phase noise measurement can be switched off in the submenu.
MARKER 1 (= reference marker) is used as a reference for the phase noise mea-
surement. The frequency and level of the reference marker are used as fixed refer-
ence values, i.e. the REFERENCE FIXED function is activated. After switching on
the phase noise measurement the reference level or the center frequency can thus
be set in a way that the carrier is outside the displayed frequency range, or, for
example, a notch filter is switched on to suppress the carrier.
A noise power density measurement is carried out with the delta marker or delta
markers. This measurement corresponds to the NOISE function in the MARKER
menu (MKR). The result of the phase noise measurement is the difference in level
between the reference point and the noise power density.
The following possibilities can be selected on switching on PHASE NOISE:
Operating Manual 1164.4556.12 - 06
CALC:MARK:FUNC:NOIS ON;
CALC:MARK:FUNC:NOIS:RES?
The R&S FSP is set to default setting.
Marker 1 is switched on and set to the maximum value of the dis-
played spectrum. Set marker to desired frequency using the rotary
knob.
The R&S FSP switches the sample detector on and sets the video
bandwidth to 300 kHz (0.1 × RBW). The power density level of inher-
ent noise is displayed in dBm/Hz in the marker info field.
Instrument Functions
Analyzer Mode
4.61