R&S FSQ Signal Analyzer - Rohde & Schwarz

R&S FSQ Instrument Functions
Analyzer Mode
The manual input mode of the sweep time is indicated by a green asterisk (*) on the
display. If the selected sweep time is too short for the selected bandwidth and span,
level measurement errors will occur. This happens because the available settling
time for the resolution or video filters is too short. In this case, the R&S FSQ outputs
UNCAL on the display and marks the indicated sweep time with a red asterisk (*).
Remote command: SWE:TIME:AUTO OFF;
SWE:TIME 10s
RES BW AUTO The RES BW AUTO softkey couples the resolution bandwidth to the selected span.
Changing the span causes automatic adjustment of the resolution bandwidth.
VIDEO BW
AUTO
SWEEPTIME
AUTO
Automatic coupling of resolution bandwidth to span is always recommended when a
favorable setting of the resolution bandwidth in relation to the selected span is
desired for the measurement under request.
The coupling ratio is set in the COUPLING RATIO submenu.
The RES BW AUTO softkey is only available in the frequency domain (span > 0 Hz).
The softkey is deactive in the time domain.
Remote command: BAND:AUTO ON
The VIDEO BW AUTO softkey couples the video bandwidth to the resolution bandwidth.
If the resolution bandwidth is changed, the video bandwidth is automatically
adjusted.
The coupling of the video bandwidth is always recommended when the minimum
sweep time is required for a selected resolution bandwidth. Narrower video bandwidths
require longer sweep times due to the longer settling time. Wider bandwidths
reduce the signal/noise ratio.
The coupling ratio is set in the COUPLING RATIO submenu.
The coupling of the video bandwidth to the resolution filter is also permitted for the
time domain display (span = 0).
Remote command: BAND:VID:AUTO ON
The SWEEPTIME AUTO softkey couples the sweep time to the span, video bandwidth
(VBW) and resolution bandwidth (RBW). The sweep time is automatically
adjusted on any change in span, resolution bandwidth or video bandwidth.
The softkey is only available in the frequency domain (span >0 Hz). It is blanked in
the time domain.
The R&S FSQ always selects the shortest sweep time possible without falsifying the
signal. The maximum level error compared to using a longer sweep time is < 0.1 dB.
If additional bandwidth and level errors are to be avoided, the sweep time is to be
set to three times the time offered in coupled mode.
The frequency sweep rates required when using the quasipeak detector are defined
in Annex B in CISPR 16-2-x:
Band A Band B Band C/D
Frequency range < 150 kHz 150 kHz to 30 MHz > 30 MHz
IF bandwidth 200 Hz 9 kHz 120 kHz
Frequency scan rate 20 s/kHz 200 s/MHz 20 s/MHz
Operating Manual 1313.9681.12 - 01 4.23