Rohde & Schwarz FPL1000 Series, User Manual

Page: 386 / 899

The Spectrum Application (RF Measurements)
R&S
®
FPL1000
386 User Manual 1178.3370.02 ─ 03
The setting range is ±200 dB in 0.01 dB steps.
Note, however, that the internal reference level (used to adjust the hardware settings to
the expected signal) ignores any "Reference Level Offset" . Thus, it is important to
keep in mind the actual power level the R&S
FPL1000 must handle. Do not rely on the
displayed reference level (internal reference level = displayed reference level - offset).
For details, see "Reference level offset" on page 382.
Remote command:
DISPlay[:WINDow<n>]:TRACe<t>:Y[:SCALe]:RLEVel:OFFSet
on page 658
Unit ← Reference Level
The R&S FPL measures the signal voltage at the RF input.
In the default state, the level is displayed at a power level of 1 mW (= dBm). Via the
known input impedance (50 Ω or 75 Ω, see " Impedance " on page 364), conversion to
other units is possible.
The following units are available and directly convertible:
●
dBm
●
dBmV
●
dBμV
●
dBμA
●
dBpW
●
Volt
●
Ampere
●
Watt
Remote command:
INPut:IMPedance
on page 670
CALCulate<n>:UNIT:POWer
on page 657
Setting the Reference Level Automatically ( Auto Level ) ← Reference Level
Automatically determines a reference level which ensures that no overload occurs at
the R&S
FPL for the current input data. At the same time, the internal attenuators are
adjusted so the signal-to-noise ratio is optimized, while signal compression and clip-
ping are minimized.
To determine the required reference level, a level measurement is performed on the
R&S
FPL.
If necessary, you can optimize the reference level further. Decrease the attenuation
level manually to the lowest possible value before an overload occurs, then decrease
the reference level in the same way.
You can change the measurement time for the level measurement if necessary (see "
Changing the Automatic Measurement Time ( Meastime Manual )" on page 420).
Remote command:
[SENSe:]ADJust:LEVel
on page 648
Attenuation Mode / Value
The RF attenuation can be set automatically as a function of the selected reference
level (Auto mode). This ensures that no overload occurs at the RF INPUT connector
for the current reference level. It is the default setting.
Amplitude and Vertical Axis Configuration