R&S FSW Series, Руководство пользователя

Страница: 454 / 1450

Common Measurement Settings
R&S
®
FSW
454 User Manual 1173.9411.02 ─ 43
Setting the Reference Level Automatically (Auto Level) ← Reference Level
Automatically determines a reference level which ensures that no overload occurs at
the R&S
FSW for the current input data. At the same time, the internal attenuators and
the preamplifier (for analog baseband input: the full scale level) are adjusted so the sig-
nal-to-noise ratio is optimized, while signal compression and clipping are minimized.
To determine the required reference level, a level measurement is performed on the
R&S
FSW.
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 499).
Remote command:
[SENSe:]ADJust:LEVel
on page 1067
RF Attenuation
Defines the attenuation applied to the RF input of the R&S FSW.
Attenuation Mode / Value ← RF Attenuation
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.
By default and when no (optional) electronic attenuation is available, mechanical
attenuation is applied.
In "Manual" mode, you can set the RF attenuation in 1 dB steps (down to 0 dB). Other
entries are rounded to the next integer value. The range is specified in the data sheet.
If the defined reference level cannot be set for the defined RF attenuation, the refer-
ence level is adjusted accordingly and the warning "limit reached" is displayed.
NOTICE! Risk of hardware damage due to high power levels. When decreasing the
attenuation manually, ensure that the power level does not exceed the maximum level
allowed at the RF input, as an overload may lead to hardware damage.
For details, see
Chapter 8.4.1.2, "RF Attenuation" , on page 450.
Remote command:
INPut<ip>:ATTenuation
on page 1041
INPut<ip>:ATTenuation:AUTO
on page 1042
Using Electronic Attenuation
If the (optional) Electronic Attenuation hardware is installed on the R&S FSW, you can
also activate an electronic attenuator.
In "Auto" mode, the settings are defined automatically; in "Manual" mode, you can
define the mechanical and electronic attenuation separately.
Note: Electronic attenuation is not available for stop frequencies (or center frequencies
in zero span) above 15 GHz.
In "Auto" mode, RF attenuation is provided by the electronic attenuator as much as
possible to reduce the amount of mechanical switching required. Mechanical attenua-
tion may provide a better signal-to-noise ratio, however.
Amplitude and Vertical Axis Configuration