Measurement Basics
R&S
®
FSW-K7
28
User Manual 1173.9240.02 ─ 23
Demodulation BW
Sample Rate (Flat Top)
Sample Rate (Gaussian Top)
40 MHz*
1
64 MHz
160 MHz
80 MHz*
3)
128 MHz
320 MHz
160 MHz*
4)
200 MHz
640 MHz
320 MHz
5)
400 MHz
500 MHz
6)
600 MHz
* Gaussian filter curve is limited by I/Q bandwidth
1)
only available with option B28
2)
only available with option B40
3)
only available with option B80
4)
only available with option B160
5)
only available with option B320
6)
only available with option B500
Large numbers of samples
Principally, the R&S
FSW can handle up to 1.6 million samples. However, when
480001 samples are exceeded, all traces that are not currently being displayed in a
window are deactivated to improve performance. The traces can only be activated
again when the samples are reduced.
Effects of measurement time on the stability of measurement results
Despite amplitude and frequency modulation, the display of carrier power and carrier
frequency offset is stable.
This is achieved by a digital filter which sufficiently suppresses the modulation, provi-
ded, however, that the measurement time is ≥ 3 x 1 / modulation frequency, i.e. that at
least three periods of the AF signal are recorded.
The mean carrier power for calculating the AM is also calculated with a digital filter that
returns stable results after a measurement time of ≥ 3 x 1 / modulation frequency, i.e.
at least three cycles of the AF signal must be recorded before a stable AM can be
shown.
4.4 AF Triggers
The Analog Demodulation application allows triggering to the demodulated signal. The
display is stable if a minimum of five modulation periods are within the recording time.
Triggering is always DC-coupled. Therefore triggering is possible directly to the point
where a specific carrier level, phase or frequency is exceeded or not attained.
AF Triggers
