R&S ESU Series Operating Manual page 186

R&S ESU
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:
No marker enabled:
[MKR FCTN]
[PHASE NOISE]
Markers are enabled:
[MKR FCTN]
[PHASE NOISE]
If further markers are enabled during the phase noise measurement, they automati-
cally become delta markers and measure the phase noise at their respective posi-
tions.
When the phase noise measurement is switched off, the marker configuration
remains unchanged and the delta markers measure the relative level to the refer-
ence marker (MARKER 1).
The PHASE NOISE function measures the noise power at the delta markers
referred to 1 Hz bandwidth. The sample detector is automatically used and the video
bandwidth set to 0.1 times the resolution bandwidth (RBW). The two settings are
taken into account in the correction values used for the noise power measurement.
To obtain stable results, two pixels on the right and the left of the respective delta
marker position are taken for the measurement. The procedure for determining the
noise power is identical to the method used for the noise power measurement (see
NOISE softkey). The measured noise level referred to 1 Hz bandwidth is subtracted
from the carrier level at the reference marker (MARKER 1). The measured values
are displayed in the delta marker field in dBc/Hz (= spacing in dB of the noise power
from the carrier level in 1 Hz bandwidth).
If several delta markers are enabled, only the value read by the active marker is
shown in the marker field. If several delta markers are active, their measurement
results are shown in the marker info field.
Operating Manual 1302.6163.12 - 03
MARKER 1 is enabled and set to peak.
MARKER 1 becomes the reference marker, MARKER 2 the delta
marker; frequency = frequency of the reference marker. The
delta marker is the active marker, i.e. it can be moved with the
rotary knob or adjusted by entering numerals.
The PHASE NOISE function is switched on and the measured
value is output.
The previous marker configuration remains unchanged.
MARKER 1 becomes the reference marker. If other markers are
enabled, they become delta markers and measure the phase
noise at their respective positions.
Instrument Functions
Analyzer Mode
4.155