Agilent Technologies Agilent 33500 Series, Руководство пользователя

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Chapter 5 Tutorial
Frequency Sweep
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5
Frequency Sweep
Frequency sweeping is similar to FM, but no modulating waveform is
used. Instead, the instrument sets the output frequency based on either
a linear or logarithmic function, or a list of up to 128 user-specified
frequencies. In a linear sweep the output frequency changes in a
constant “hertz per second” manner, but in a logarithmic sweep the
frequency changes in a constant “octaves per second” or “decades per
second” way. Logarithmic sweeps let you cover wide frequency ranges
where resolution at low frequencies could be lost with a linear sweep.
Frequency sweeps are characterized by a sweep time (during which the
frequency changes smoothly from the start frequency to the stop
frequency), a hold time (during which the frequency stays at the stop
frequency), and a return time (during which the frequency returns
smoothly to the start frequency). Trigger settings determine when the
next sweep begins. The returns are always linear.