Rohde & Schwarz SMU200A - Automatic Level Control - ALC

Instrument Function
R&S
®
SMU200A
221Operating Manual 1007.9845.32 ─ 15
To open the "RF Level/EMF" dialog, select "RF/A Mod > Configure > Level/EMF" or use
the MENU key under "RF/A Mod".
Power-On State - RF Signal
Selects the state which the RF output is to assume after the instrument is switched on.
"RF Off"
The output is deactivated when the instrument is switched on.
"Previous Set-
ting"
When the instrument is switched on, the output assumes the same state
as it had when the instrument was switched off.
SCPI command:
:OUTPut<hw>[:STATe]:PON on page 556
Display Level as Voltage of EMF - RF Level
Activates display of the signal level as voltage of the EMF (no-load voltage). If this setting
is deactivated, the level is displayed as a voltage over a 50 Ohm load (preset state).
SCPI command:
n.a.
5.5.8 Automatic Level Control - ALC
Automatic level control (Automatic Level Control) can be used with almost all applica-
tions, especially I/Q modulation and amplitude modulation. It only has to be deactivated
for certain settings in the baseband and when I/Q impairments (Impairments State On)
are activated. This is indicated under the respective function.
The level control status is permanently displayed as a status message in the info line.
The standard operating status is level control "On". This provides the highest level accu-
racy. The preset is "Auto". In this mode the level control is automatically adapted to the
operating conditions.
Level control can be switched to "Sample&Hold" or "On" for particular applications. The
"Sample&Hold" state (level control Off) is recommended if in CW mode the signal/inter-
modulation ratio is to be improved for multi-transmitter measurements.
If "Sample&Hold" is selected, the level is recalibrated for every level and frequency set-
ting. For this purpose, level control is activated briefly at a defined signal, the level adjuster
is then held at the attained value and level control is activated.
If "On" and "Attenuator Mode Fixed" is selected, the level is recalibrated for every level
and frequency setting. For this purpose, level control is activated briefly at a defined
signal, the level adjuster is then held at the attained value and level control is activated
the uninterrupted level settings are made.
RF Signal and Analog Modulations - RF Block