R&S FSW Series, Руководство пользователя

Страница: 368 / 1450

Common Measurement Settings
R&S
®
FSW
368 User Manual 1173.9411.02 ─ 43
Radio Frequency State ............................................................................................... 368
Input Coupling ............................................................................................................. 368
Impedance .................................................................................................................. 368
Direct Path .................................................................................................................. 369
High Pass Filter 1 to 3 GHz .........................................................................................369
YIG-Preselector ...........................................................................................................369
Preselector Adjust ....................................................................................................... 370
Input Connector ...........................................................................................................370
Radio Frequency State
Activates input from the "RF Input" connector.
For R&S FSW85 models with two input connectors, you must define which input
source is used for each measurement channel.
"Input 1" 1.00 mm RF input connector for frequencies up to 85 GHz (90 GHz
with option R&S FSW-B90G)
"Input2" 1.85 mm RF input connector for frequencies up to 67 GHz
Remote command:
INPut<ip>:SELect
on page 1072
INPut<ip>:TYPE
on page 1073
Input Coupling
The RF input of the R&S FSW can be coupled by alternating current (AC) or direct cur-
rent (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 1069
Impedance
The R&S FSW 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
FSW, 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
FSW, it can convert the measured units accordingly so that the results are calcu-
lated correctly.
(See "Reference Level" on page 452).
This function is not available for input from the optional Digital Baseband Interface. Not
all settings are supported by all R&S
FSW applications.
Data Input and Output