R&S 1129.7246.03, Operating Manual

Page: 185 / 855

R&S ESU Instrument Functions
Analyzer Mode
4.154 Operating Manual 1302.6163.12 - 03
• Sample detector
As a result of video filter averaging and trace averaging, 1.05 dB is added to the
marker level. This is the difference between the average value and the RMS value
of white noise.
With a logarithmic level axis, 1.45 dB is added additionally. Logarithmic averaging
is thus fully taken into account which yields a value that is 1.45 dB lower than that
of linear averaging.
• RMS detector
With the exception of bandwidth correction, no further corrections are required for
the RMS detector since it already indicates the power with every point of the trace.
To allow a more stable noise display the adjacent (symmetric to the measurement
frequency) points of the trace are averaged.
In time domain mode, the measured values are averaged versus time (after a
sweep).
Remote command:
CALC:MARK:FUNC:NOIS ON;
CALC:MARK:FUNC:NOIS:RES?
Example: Measurement of inherent R&S ESU noise
4.8.11.3 Phase Noise Measurement
PHASE NOISE
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.
[ PRESET ] The R&S ESU is set to default setting.
[ MARKER ] 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.
[ NOISE ] The R&S ESU 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.
The R&S ESU 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 ESU noise
figure.
PH NOISE ON | OFF
REF POINT LEVEL
REF POINT LVL OFFSET
REF POINT FREQUENCY
PEAK SEARCH
AUTO PEAK SEARCH