Common Analysis and Display Functions
R&S
®
ESW
202User Manual 1177.6298.02 ─ 08
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
Resolution band-
width
200 Hz 9 kHz 120 kHz 1 MHz
Time constant of
the mechanical
device
160 ms 160 ms 100 ms 100 ms
The coupling of the resolution bandwidth to the frequency range with activated CISPR
average detector can be canceled using the "CISPR RBW uncoupled" softkey.
Tips regarding measurement time:
●
The relatively long time constants of the quasipeak detector result in long measure-
ment times to yield valid results.
●
Unknown signals should be measured with a measurement time of at least 1 s.
This ensures correct weighting of pulses down to a pulse frequency of 5 Hz.
●
Unmodulated sinusoidal signals and signals with a high modulation frequency can
be measured with a much shorter measurement time.
●
Slowly fluctuating signals or pulsed signals require longer measurement times.
Measurement times shorter than 20 ms
With measurement times shorter than 20 ms the detector weighting changes to plain
average weighting.
When you change the receiver frequency or the attenuation, the R&S ESW waits until
the lowpass filter has settled before starting the measurement. The measurement time
in that case depends on the resolution bandwidth and the characteristics of the signal.
The RMS Average Detector
The RMS Average detector is a combination of the RMS detector (for pulse repetition
frequencies above a corner frequency) and the Average detector (for pulse repetition
frequencies below the corner frequency). It thus achieves a pulse response curve with
the following characteristics: 10 dB/decade above the corner frequency and 20 dB/
decade below the corner frequency. The average value is determined by lowpass fil-
ters of the 2nd order (simulation of a mechanical instrument).
The detector is used, for example, to measure broadband emissions and may replace
the quasipeak detector in the future.
The filter bandwidth and time constants of the detector are coupled to the receiver fre-
quency.
Table 11-1: RMS 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
Resolution band-
width
200 Hz 9 kHz 120 kHz 1 MHz
Trace Configuration
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