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Vector Network Analyzer
R&S
®
FPC
180
User Manual 1178.4130.02 ─ 07
2. Select the "Auto Span" menu item.
The R&S
FPC automatically calculates the best span for the best length resolution.
If the required span is too large for the current center frequency, the R&S
FPC
changes the center frequency to the smallest possible frequency.
or
3. Select the "Manual Span" menu item.
4. Enter the span you need.
The R&S
FPC adopts the new span.
Note that the maximum span you can define depends on the maximum cable dis-
tance you have defined and is never greater than the span calculated by the "Auto
Span" function. The minimum span that you can set is 10
MHz.
5. Press the "Freq" key to open the frequency menu.
6. Select the "Center Frequency" menu item to define the center frequency.
The span remains the same when you change the center frequency.
Alternatively, you can define the frequency range as a function of the center fre-
quency and the start and stop frequency. The start and stop frequency in that case
define the span.
7. Select the "Start Frequency" or "Stop Frequency" menu items to define the span.
The center frequency is automatically adjusted to the frequency whose distance to
the start and stop frequency is the same.
Defining the displayed frequency range
After you have defined the span, you can define the frequency range whose results the
R&S
FPC displays.
In the default configuration, the R&S
FPC adjusts the DTF start and DTF stop fre-
quency according to the span and the center frequency. The distance from center fre-
quency to the start and stop frequency is the same. Alternatively, you can directly set a
DTF start and DTF stop frequency.
1. Press the "Freq" key to open the frequency menu.
2. Select the "Center Frequency" menu item to define the center frequency.
Coupling frequency and span settings across measurements
By default, the DTF measurement has its own configuration regarding frequency and
span settings. The other measurements (reflection S11, transmission S21 and cable
loss) use the same frequency and span settings.
You can couple the frequency and span settings across all measurements.
1. Enter the DTF measurement.
2. Press the "Span" key to open the span menu.
3. Select the "Coupled Span" menu item.
Frequency Configuration