Agilent Technologies E4428C, Руководство пользователя

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166 Chapter 4
Basic Digital Operation
Using Customized Burst Shape Curves
Using Customized Burst Shape Curves
You can adjust the shape of the rise time curve and the fall time curve using the
Rise Shape
and
Fall
Shape
editors. Each editor allows you to enter up to 256 values, equidistant in time, to define the shape of
the curve. The values are then resampled to create the cubic spline that passes through all of the sample
points.
The
Rise Shape
and
Fall Shape
table editors are available for custom real-time I/Q baseband generator
waveforms and real-time I/Q baseband generator TDMA waveforms. They are not available for waveforms
generated by the dual arbitrary waveform (dual ARB) generator.
For instructions on modifying rise and fall times and delays, see “Configuring the Burst Rise and Fall
Parameters” on page 380 .
Understanding Burst Shape
The default burst shape of each format is implemented according to the standards of the format selected. You
can, however, modify the following aspects of the burst shape:
Rise time the period of time, specified in bits, where the burst increases from
a minimum of
−
70 dB (0) to full power (1).
Fall time the period of time, specified in bits, where the burst decreases from
full power (1) to a minimum of
−
70 dB (0).
Rise delay the period of time, specified in bits, that the start of the burst rise is
delayed. Rise delay can be either negative or positive. Entering a
delay other than zero shifts the full power point earlier or later than
the beginning of the first useful symbol.
Fall delay the period of time, specified in bits, that the start of the burst fall is
delayed. Fall delay can be either negative or positive. Entering a
delay other than zero shifts the full power point earlier or later than
the end of the last useful symbol.
User-defined burst shape up to 256 user-entered values which define the shape of the curve in
the specified rise or fall time. The values can vary between 0 (no
power) and 1 (full power) and are scaled linearly. Once specified,
the values are resampled as necessary to create the cubic spline that
passes through all of the sample points.