Configuration
R&S
®
FSW-K7
119
User Manual 1173.9240.02 ─ 23
Remote command:
[SENSe:]FILTer<n>:CCIR:[:UNWeighted][:STATe]
[SENSe:]FILTer<n>:CCIR:WEIGhted[:STATe]
[SENSe:]FILTer<n>:AWEighted[:STATe]
Deemphasis
Activates a deemphasis filter with the given time constant.
Sometimes a modulated signal is extorted by a pre-emphasis filter before transmission,
for example to eliminate frequencies that are more prone to interferences. In this case,
the emphasis function must be reversed after demodulation. This is done by the deem-
phasis filter.
The deemphasis filter is active in the following demodulation bandwidth range:
25 µs:
25 kHz ≤ demodulation bandwidth ≤ 40 MHz
50 µs:
6.4 kHz ≤ demodulation bandwidth ≤ 18 MHz
75 µs:
6.4 kHz ≤ demodulation bandwidth ≤ 18 MHz
750 µs:
800 Hz ≤ demodulation bandwidth ≤ 3 MHz
Depending on the deemphasis filter, a minimum demodulation bandwidth is required
for an error less than 0.5 dB, up to a maximum AF frequency. The following table
shows the dependencies.
Deemphasis [us]
25 µs
50 µs
75 µs
750 µs
Max. AF frequency
25 kHz
12 kHz
8 kHz
800 Hz
Required demodulation bandwidth
≥ 200 kHz
≥ 100 kHz
≥ 50 kHz
≥ 6.4 kHz
For higher AF frequencies the demodulation bandwidth must be increased.
Remote command:
[SENSe:]FILTer<n>:DEMPhasis[:STATe]
[SENSe:]FILTer<n>:DEMPhasis:TCONstant
Deactivating all AF Filters
The "All Filter Off" button deactivates all AF filters for the selected evaluation.
Remote command:
5.7.4 Scaling
Access
: "Overview" > "Demod Settings" > "Scaling"
Or
: "Meas Setup" > "Demod" > "Scaling" tab
Demodulation
