GUI Reference
R&S
®
ZNB/ZNBT
375
User Manual 1173.9163.02 ─ 38
The spurious signal can be eliminated by dividing the sweep range into two segments
with different LO settings:
●
In the low-frequency segment, ranging up to the center frequency of the bandpass
filter, the frequency of the local oscillator is set to LO < RF. This ensures that the
spurious signal b'
2
is not measured at port 2.
●
In the high-frequency segment, starting at the center frequency of the bandpass fil-
ter, the frequency of the local oscillator is set to LO > RF. If the center frequency is
larger than B
+
– 2*IF, then there is no distortion from b'
2
.
Remote command:
AGC Mode
Configures the Automatic Gain Control (AGC).
In
"Auto"
mode the analyzer automatically adapts its receiver step attenuator settings
to the RF input level (
→
Automatic or Adaptive Gain Control, AGC). The A/D converter
is always operated at optimum input level, selecting one of the following gain settings
for every measurement point:
●
"Low Dist"
, corresponding to a lower internal A/D converter input level. This set-
ting allows for a high RF overdrive reserve and is appropriate for high RF input lev-
els.
●
"Low Noise"
corresponding to a higher internal A/D converter input level. This set-
ting increases the dynamic range and is appropriate for low RF input levels.
"Low Dist" and "Low Noise" can also be selected
statically
, completely disabling the
adaptive behavior. This is appropriate if the characteristics of the input paths must be
constant, e.g. because
●
interfering signal contributions originating from the receiver (noise, nonlinear contri-
butions) must not change during the measurement.
●
a large interfering signal in the vicinity of the measured signal must not overdrive
the receiver.
"Manual"
mode allows to select the preferred "AGC Mode" per sweep segment, drive
"Drive-port specific settings"
Remote command:
[SENSe<Ch>:]POWer:GAINcontrol:GLOBal
Manual Config...
The "Manual Config..." button opens the "AGC Manual Configuration" dialog that
allows to configure the Automatic Gain Control for the individual sweep segments,
drive ports and receivers. This button is enabled in "Manual"
Segmented AGC
"Segmented AGC" enables segment specific gain settings. It is available for "Segmen-
ted" sweep type only.
Remote command:
[SENSe<Ch>:]SEGMent<Seg>:POWer:GAINcontrol:CONTrol
Channel Config Softtool
