The Spectrum Application (RF Measurements)
R&S
®
FPL1000
256
User Manual 1178.3370.02 ─ 11
Table 6-16: Required parameters depending on frequency for CISPR quasi-peak detector
Band A
Band B
Band C/D
Frequency range
<
150
kHz
150
kHz to 30
MHz
>
30
MHz
Resolution bandwidth
200 Hz
9 kHz
120 kHz
Charge time
45 ms
1 ms
1 ms
Discharge time
500 ms
160 ms
550 ms
Time lag of the simulated
pointer instrument
160 ms
160 ms
100 ms
Consider the following when defining the dwell time:
●
Unknown signals
: select a dwell time of at least 1
second to ensure that pulses
down to a frequency of 5
Hz are weighted correctly
●
Known signals
: shorter dwell time possible, as the signal level does not change
during the final measurement
CISPR Average detector (CISPR filter only)
The CISPR Average detector displays a weighted average signal level according to
CISPR 16-1-1.
The average value according to CISPR 16-1-1 is the maximum value detected while
calculating the linear average value during the specified dwell time.
The CISPR Average detector is only available for the CISPR filter.
The CISPR Average detector is applied to measure pulsed sinusoidal signals with a
low pulse frequency, for example. It is calibrated with the RMS value of an unmodula-
ted sinusoidal signal. The average value is determined by lowpass filters of the 2nd
order (simulating a mechanical pointer instrument).
The filter bandwidth and time lag of the detector depend on the measured frequency.
The time lag of the simulated pointer instrument reflects the weighting factor of the sig-
nal depending on its form, modulation, etc.
Table 6-17: Required parameters depending on frequency for CISPR Average detector
Band A
Band B
Band C/D
Band E
Frequency range
<150
kHz
150
kHz to 30
MHz
30
MHz to 1
GHz
>1
GHz
IF bandwidth
200
Hz
9
kHz
120
kHz
1
MHz
Time lag of the
simulated pointer
instrument
160
ms
160
ms
100
ms
100
ms
Consider the following when defining the dwell time:
●
Unknown signals
: select a dwell time of at least 1
second to ensure that pulses
down to a frequency of 5
Hz are weighted correctly
●
Pulsed signals or signals that fluctuate slowly
: the dwell time must cover at
least the time until the first signal peak is measured; can require long dwell time
Measurements and Results
