Rohde & Schwarz FSWP Series - Page 42

Configuration
R&S
®
FSWP
42User Manual 1177.5856.02 ─ 07
Attenuator", on page 113 and Chapter 8.6.5, "Configuring the Preamplifier",
on page 114.
Radio Frequency State ................................................................................................ 42
Input Coupling ..............................................................................................................42
Impedance ................................................................................................................... 42
High Pass Filter 1 to 3 GHz ..........................................................................................43
YIG-Preselector ............................................................................................................43
Radio Frequency State
Activates input from the "RF Input" connector.
Remote command:
INPut<ip>:SELect on page 108
Input Coupling
The RF input of the R&S FSWP can be coupled by alternating current (AC) or direct
current (DC).
AC coupling blocks any DC voltage from the input signal. This is the default setting to
prevent damage to the instrument. Very low frequencies in the input signal may be dis-
torted.
However, some specifications require DC coupling. In this case, you must protect the
instrument from damaging DC input voltages manually. For details, refer to the data
sheet.
Remote command:
INPut<ip>:COUPling on page 106
Impedance
The R&S FSWP has an internal impedance of 50 Ω. However, some applications use
other impedance values. In order to match the impedance of an external application to
the impedance of the R&S FSWP, an impedance matching pad can be inserted at the
input. If the type and impedance value of the used matching pad is known to the
R&S FSWP, it can convert the measured units accordingly so that the results are cal-
culated correctly.
This function is not available for input from the optional Digital Baseband Interface. Not
all settings are supported by all R&S FSWP applications.
The impedance conversion does not affect the level of the output signals (such as IF,
video, demod, digital I/Q output)
"50Ω"
(Default:) no conversion takes place
"75Ω"
The 50 Ω input impedance is transformed to a higher impedance
using a 75 Ω adapter of the selected "Pad Type": "Series-R" (default)
or "MLP" (Minimum Loss Pad)
"User"
The 50 Ω input impedance is transformed to a user-defined impe-
dance value according to the selected "Pad Type": "Series-R"
(default) or "MLP" (Minimum Loss Pad)
Remote command:
INPut<ip>:IMPedance on page 108
INPut<ip>:IMPedance:PTYPe on page 108
Configuring Data Inputs and Outputs