Rohde & Schwarz SMC100A - NRP-Z Level Control

Instrument Function
R&S
®
SMC100A
135Operating Manual 1411.4060.32 ─ 09
RF output behavior during Sample & Hold depends on the configuration of your instru-
ment. Instruments equipped with...:
●
an electronic step attenuator
The level is decreased by 30 dB.
●
a mechanical step attenuator
The level control status is permanently displayed as a status message in the info line.
Automatic Level Control Settings
To open the "Automatic Level Control" dialog, select "RF" > "Configure" > "Automatic
Level Control" or use the MENU key under "RF".
The combined dialog "ALC / UCOR" is divided into the several sections and provides
access to the "Automatic Level Control" settings and to function "User Correction", see
Chapter 5.3.5.6, "User Correction", on page 140).
State - ALC
Activates/deactivates internal level control.
"Auto"
The instrument selects the most appropriate ALC mode automati-
cally.
ALC is on in most operating conditions. Default state.
"On"
Activates ALC, regardless of the operating conditions.
"Off (Sample & Hold)"
Deactivates internal level control.
Sample & hold closes the level control loop at every frequency and
level change for a short period of time. The level control voltage is
sampled and then clamped.
Remote command:
[:SOURce<hw>]:POWer:ALC[:STATe] on page 313
Search Once - ALC
Forces the generator to execute level adjustment once, although the "Sample & Hold"
mode is active.
Remote command:
[:SOURce<hw>]:POWer:ALC:SONCe on page 313
5.3.5.5 NRP-Z Level Control
With the NRP-Z Level Control function, you can achieve a very stable and accurate RF
power supplied to your DUT. With the aid of a downstream control circuit, a CLPC
(Closed Loop Power Control), you can detect frequency response characteristics of the
RF Block