Instrument Function
R&S
®
SMF100A
153
Operating Manual 1167.2319.02 ─ 12
Variation Step
Sets the user-defined step width. This step width is used when entering the RF fre-
quency using the rotary knob. Frequency variation with this step width must also be
activated with "Variation Active".
Remote command:
[:SOURce<hw>]:FREQuency:STEP[:INCRement]
5.3.2.6
The Configurable Main PLL Bandwidth
The latest generation of the R&S
SMF provides an extended SynEx RF assembly
which improves the phase noise performance. It is achieved by reducing the PLL band-
width of the main synthesizer (see
on page 152) for a certain fre-
quency range and offset.
●
To change the PLL bandwidth requires that your device is equipped with the
enhanced phase noise and FM/
ɸ
M modulator (R&S
SMF-B22) and the extended
synthesis assembly (SynEx) with part number 1413.1800.02. This assembly is
installed in all instruments with serial number 112000 or higher.
If your instrument is equipped with the previous version of the SynEx assembly, the
normal bandwidth is provided and th
parameter is suppressed
in the settings dialog.
●
The range of the adjustable PLL bandwidth is limited to 3
GHz. For frequencies
higher than 3
GHz, the instrument uses the standard bandwidth automatically. The
selection switches to "Normal" mode.
●
The narrow bandwidth increases the frequency settling time to approximately 1
ms.
Therefore, the narrow PLL bandwidth mode and the list mode exclude each other.
To generate a signal in list mode, the standard PLL bandwidth setting is required.
RF Frequency Block
