Configuration
R&S
®
FSV/A3000 I/Q
Analyzer
53
User Manual 1178.8536.02 ─ 01
Direct Path
Enables or disables the use of the direct path for small frequencies.
In spectrum analyzers, passive analog mixers are used for the first conversion of the
input signal. In such mixers, the LO signal is coupled into the IF path due to its limited
isolation. The coupled LO signal becomes visible at the RF frequency 0
Hz. This effect
is referred to as LO feedthrough.
To avoid the LO feedthrough the spectrum analyzer provides an alternative signal path
to the A/D converter, referred to as the
direct path
. By default, the direct path is
selected automatically for RF frequencies close to zero. However, this behavior can be
disabled. If "Direct Path" is set to "Off" , the spectrum analyzer always uses the analog
mixer path.
"Auto"
(Default) The direct path is used automatically for frequencies close
to zero.
"Off"
The analog mixer path is always used.
Remote command:
YIG-Preselector
Activates or disables the YIG-preselector, if available on the R&S
FSV/A.
An internal YIG-preselector at the input of the R&S
FSV/A ensures that image frequen-
cies are rejected. However, this is only possible for a restricted bandwidth. To use the
maximum bandwidth for signal analysis you can disable the YIG-preselector at the
input of the R&S
FSV/A, which can lead to image-frequency display.
Note that the YIG-preselector is active only on frequencies greater than 7.5
GHz.
Therefore, switching the YIG-preselector on or off has no effect if the frequency is
below that value.
Note:
For the following measurements, the YIG-Preselector is off by default (if available).
●
I/Q Analyzer
●
GSM
●
VSA
Remote command:
5.3.1.2
Settings for Input from I/Q Data Files
Access
: "Overview" > "Input/Frontend" > "Input Source" > "I/Q File"
Or:
[INPUT/OUTPUT] > "Input Source Config" > "Input Source" > "I/Q File"
Data Input and Output Settings