R&S SMJ100A, Руководство по эксплуатации, Страница: 236 / 874

Instrument Function
R&S
®
SMJ100A
220 Operating Manual 1403.7458.32 ─ 14
5.5.6.3 Power-On/EMF Settings
The power-on behavior of the R&S SMJ and the level display in the display header are
set in the "Power-On / EMF Settings" section of the "RF Level/EMF/ALC/UCOR" dia-
log.
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.
Remote command:
:OUTPut<hw>[:STATe]:PON
on page 557
Display Level as Voltage of EMF - RF Level
Activates display of the signal level as voltage of the EMF (no-load voltage). If this set-
ting is deactivated, the level is displayed as a voltage over a 50 Ohm load.
Note: This setting is not affected by an instrument preset (PRESET key),
*RST
) or the
"Save/Recall" function. Only the Chapter 5.2.3.18, "Factory Preset" , on page 152
resets the setting.
Remote command:
[:SOURce<hw>]:POWer:EMF:STATe
on page 764
5.5.7 Automatic Level Control - ALC
Your signal generator is equipped with an automatic level control unit to obtain best RF
level accuracy.
A utomatic L evel C ontrol (ALC) is an adaptive control system to stabilize the RF output
level. It continuously monitors the current level and adjusts it to keep a steady state
over temperature and time.
ALC is active in almost all applications by default. However, the Pulse Modulation
mode excludes ALC, as the control loop would detect incorrect values and result in
level deviations.
Also note that ALC may detect incorrect values in
multi-transmitter test setups. If mul-
tiple generators are coupled, reverse power may affect the ALC readings. Based on
incorrect values, ALC would have an impact on the signal to intermodulation ratio.
RF Signal and Analog Modulations - RF Block