Keysight E8663D, Руководство пользователя

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146 Keysight E8357D/67D & E8663D PSG User’s Guide
Optimizing Performance
Using the ALC
Figure 4-1 Decision Tree for Automatic ALC Bandwidth Selection
To Select an ALC Bandwidth
Press Amplitude > ALC BW > 100 Hz , 1 kHz , 10 kHz , or 100 kHz .
This overrides the signal generator’s automatic ALC bandwidth selection with
your specific selection.
For waveforms with varying amplitudes, high crest factors, or both, the
recommended ALC loop bandwidth is 100 Hz. Limiting the loop bandwidth of
the ALC circuit will prevent the ALC from sampling the fast rising edges of
pulsed waveforms with high crest factors found in formats such as 802.11b,
CDMA, and OFDM. A limited, or narrow bandwidth will result in a longer ALC
sample time and a more accurate representation of the signal’s level.
NOTE
Do not use the 10 kHz ALC bandwidth for any I/Q modulated signal, as the
ALC integration time is too short. For CW signals, you can use higher ALC
bandwidths.
RF OUTPUT
< 2 MHz
AM OFF
PULSE OFF
AM OFF
PULSE ON
AM ON
PULSE ON
AM ON
PULSE OFF
ALC BW
100 Hz
ALC BW
1 kHz
ALC BW
10 kHz
No
No No
Yes
Yes
Yes Yes
ALC BW
100 kHz
ARB On
Yes
No
No
Yes