Keysight E8663D, Руководство пользователя

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Keysight E8357D/67D & E8663D PSG User’s Guide 113
Basic Digital Operation
Using Waveform Markers
This is especially important when the segment plays as part of a sequence
because the previously played segment could have different marker and
routing settings.
ALC Hold Marker Function (For Instruments with serial prefixes
>=US4722/MY4722)
While you can set a marker function (described as Marker Routing on the
softkey label) either before or after you set marker points ( page 118 ), setting a
marker function before setting marker points may cause power spikes or loss of
power at the RF output.
Use the ALC hold function by itself when you have a waveform signal that
incorporates idle periods, or when the increased dynamic range encountered
with RF blanking ( page 124 ) is not desired.
The ALC hold marker function holds the ALC circuitry at the average (RMS)
value of the sampled points set by the marker(s). For both positive and
negative marker polarity, the ALC samples the RF output signal (the carrier
plus any modulating signal) when the marker signal goes high:
The marker signal has a minimum of a two sample point delay in its response
relative to the waveform signal response. To compensate for the marker signal
delay, offset marker points from the waveform sample at which you want the
ALC sampling to begin.
NOTE
Because it can affect the waveform’s output amplitude, do not use the ALC
hold for longer than 100 ms. For longer time intervals, refer to “Setting Power
Search Mode” on page 317 .
Positive: The signal is sampled during the on marker points.
Negative The signal is sampled during the off marker points.
Positive Polarity