NF FRA51615, Instruction Manual

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5.7 Amplitude compression
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FRA 51615
that the measured value of the reference channel has this value.
[OUTPUT LIMIT] : This is the maximum amplitude of the oscillator (output control).
[TOLERANCE] : This is the permissible error of the target level.
[RETRY TIMES] : The maximum number of times the process is repeated.
[CORRECTION FACTOR] : This is the correction factor.
For the parameter setting ranges, etc., refer to " 3.5.1 OSC dialog ".
■ The correction factor
The correction factor [CORRECTION FACTOR] is set for measurements where sudden changes in
amplitude are not desired or when measuring DUTs for which the gain varies with the signal level (DUTs
that have strong nonlinearity). The correction factor corresponds to the gain adjustment of an automatic
control loop that includes the equipment under test. If the amplitude control is unstable (divergent),
reduce the correction factor to a small value.
■ About the oscillator amplitude after amplitude compression
When you use the amplitude compression function, the oscillator amplitude setting (
【
OSC
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–
[AMPLITUDE] ) also changes to accord with the adjusted amplitude. Please note that the value does not
return to the amplitude value that had been set prior to the amplitude compression, even if the amplitude
compression function is turned off. (The changed amplitude value is the final value.)
■ If amplitude control is not possible
If the result is not within the permissible error, even if the maximum number of retries is exceeded, and
an amplitude setting that exceeds the output amplitude control value is needed, the amplitude control fails,
but the measurement data is still obtained. For a sweep measurement, the amplitude control is attempted
again at the next frequency.