Kroks ARINST VNA-PR1, Руководство пользователя

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2-port vector network analyzer ARINST VNA-PR1
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Figure 10.14 - Selecting units and entering cable length
To obtain correct measurement results, it is necessary to choose a scanning step several times less
than the period of phase oscillations. The period of the oscillations is equal to the ratio of the propagation
speed to twice the value of the cable length.
where SPAN
– scanning frequency range (Hz), defined as the difference between the final and initial
frequencies (F
STOP
– F
START
)
N
– quantity of scan points
С – speed of light, m / s
VF
– speed factor
L
– cable length, m
10.9. Group delay plot
10.9. The group delay is the propagation time of the signal through the analyzed circuit. This signal
delay will differ for different frequencies if the test device does not have a linear phase response (PFC).
To determine the group delay of the signal phase in a certain frequency range, a plot is used (figure
10.15). By measuring the phase of parameter S21, the analyzer calculates the group delay of the test
device. The resulting values are displayed in nanoseconds (ns).
Figure 10.15 - Group delay plot