R&S SMJ100A, Operating Manual

Page: 248 / 874

Instrument Function
R&S
®
SMJ100A
232 Operating Manual 1403.7458.32 ─ 14
To increase the level accuracy and provide precise measurement results, the instru-
ment considers the changes in VSWR for the different attenuator settings. It automati-
cally selects the corresponding reference level for each of the attenuator steps. For
ranges from 40 dB on, the changes in VSWR are negligible; it is thus sufficient to apply
the same correction value as for 35 dB attenuation.
The acquired measurement data is stored in a multi level correction table, containing
one row per each frequency and ten additional power columns.
1 = single level measurement power correction at the output level
2 = "Power [1]" power correction at high power attenuator settings
3a .. 3h = "Power [2] .. Power [9]" power corrections at the different attenuator steps
The R&S SMJ performs the multi level correction measurements in addition to a single
level correction measurement. This enables you, with one single user correction list, to
switch between the single and the multi level correction results.
Multi Level Values
The measurement values for the different attenuator settings are retrieved separately.
The numeric suffix at MLEV correlates to the index of the column, e.g. suffix 3 denotes
the column with the values for attenuator setting 5 dB.
Remote command:
[:SOURce<hw>]:CORRection:CSET:DATA:POWer:MLEVel:STATe
on page 701
[:SOURce<hw>]:CORRection:CSET:DATA:POWer:MLEVel<ch>?
on page 700
5.5.9 Reverse Power Protection
Starting from serial number 101001, the R&S SMJ (all frequency options) is equipped
against overloading by an external signal applied to the RF output.
The reverse power protection is tripped when the power of the external signal becomes
too high. A relay opens and interrupts the internal connection to the RF output. This
condition is indicated in the display header by the "OVERLOAD" status message.
Overload
If an "Overload" status message is indicated in the display header, reset the overload
protection by pressing the RF ON/OFF key.
The RF input is activated when the overload protection is reset.
Remote command:
:OUTPut<hw>:PROTection:TRIPped?
on page 556
:OUTPut<hw>:PROTection:CLEar
on page 556
:OUTPut<hw>[:STATe]
on page 557
RF Signal and Analog Modulations - RF Block