Agilent Technologies E5070B, Руководство пользователя

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270 Chapter 6
Data Analysis
Determining the Bandwidth of the Trace (Bandwidth Search)
Determining the Bandwidth of the Trace (Bandwidth Search)
The bandwidth search is a function for determining the bandwidth of the trace, center
frequency, cut-off points (on the higher frequency and the lower frequency sides), Q, and
insertion loss, based on the position of the active marker. The definitions of the parameters
determined through the bandwidth search are shown in Figure 6-13 and Table 6-2. The user
specifies the defined bandwidth value as shown in Figure 6-13.
Figure 6-13 Bandwidth parameters
Table 6-2 Definitions of Bandwidth Parameters
Bandwidth Parameter Definition
Insertion loss (
loss
) The measured value of the position of the active marker at
the time the bandwidth search is executed.
Lower frequency cut-off point
(
low
)
Lowest frequency of two measurement points, both
separated by the defined bandwidth value from the active
marker position.
Higher frequency cut-off point
(
high
)
Highest frequency of two measurement points, both
separated by the defined bandwidth value from the active
marker position.
Center frequency (
cent
) Frequency at the midpoint between the lower frequency
cut-off and higher frequency cut-off points. (
high low +
2
--------------------------- ).
Bandwidth (
BW
) The difference in frequency between the higher frequency
cut-off and lower frequency cut-off points (
high low – ).
Q
Value obtained by dividing the center frequency by the
bandwidth (
cent
BW
----------- ).
Executing a Bandwidth Search
Step 1. Place the active marker at the desired point on the trace on which the bandwidth search is