Rohde & Schwarz R&S FSP Series, Operating Manual

Page: 88 / 796

R&S FSP Instrument Functions
Analyzer Mode
4.16 Operating Manual 1164.4556.12 - 06
UNIT
The UNIT softkey opens a submenu to select the unit for the level axis.
The default setting is dBm.
In general, the R&S FSP measures the signal voltage at the RF input. The level dis-
play is calibrated in rms values of an unmodulated sinewave signal. In the default
state, the level is displayed at a power of 1 mW (= dBm). Via the known input resis-
tance of 50
Ω
or 75W, conversion to other units is possible. The units dBm, dBmV,
dBµV, dBµA, dBpW, V, A and W are directly convertible.
Remote command:
CALC:UNIT:POW DBM
RF ATTEN
MANUAL The RF ATTEN MANUAL softkey allows the attenuation to be entered irrespective of
the reference level.
The attenuation can be set in 10 dB steps between 0and 70 dB (in 5 dB steps
between 0 and 75 dB if option B25,
Electronic Attenuator , is fitted).
Other entries will be rounded to the next higher integer value.
If the defined reference level cannot be set for the given RF attenuation, the refer-
ence level will be adjusted accordingly and the warning "Limit reached" will be out-
put.
Remote command:
INP:ATT 40 DB
RF ATTEN
AUTO
The RF ATTEN AUTO softkey sets the RF attenuation automatically as a function of
the selected reference level.
This ensures that the optimum RF attenuation desired by the user is always used.
RF ATTEN AUTO is the default setting.
Remote command:
INP:ATT:AUTO ON
MIXER
The MIXER softkey opens a submenu for defining the maximum mixer level attain-
able for the selected reference level.
dBm
dBmV
dB
µ
V
dB
µΑ
dB
µ
W
VOLT
AMPERE
WATT
The 0 dB value can be entered only via the numeric keypad in order to protect the
input mixer against accidental overload.