Rohde & Schwarz FSW13, Руководство пользователя

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Common Measurement Settings
R&S
®
FSW
402 User Manual 1173.9411.02 ─ 19
● Reduce the "Range" of the y-axis to a small area around the required level. If
necessary, change the "Ref Level Position" so the required range remains visi-
ble.
● Select "Linear Unit" scaling.
Now you can set a marker at the point in question and read the result.
5. To detect a spurious signal close to the noise floor:
● Set the "RF attenuation" to "Manual" mode and reduce the "Value" to lower the
noise floor.
● Select "Relative - Logarithmic" scaling.
Now you can determine if any spurious levels of a certain size are visible.
6.5 Bandwidth, Filter and Sweep Configuration
The basic bandwidth, filter and sweep settings that apply to most measurements are
described here. These parameters define how the data is measured: how much data is
collected internally and which filters are used.
● Impact of the Bandwidth, Filter and Sweep Settings .............................................402
● Bandwidth, Filter and Sweep Settings .................................................................. 408
● Reference: List of Available RRC and Channel Filters ......................................... 416
6.5.1 Impact of the Bandwidth, Filter and Sweep Settings
The bandwidth, filter and sweep settings are closely related and interdependant. The
values available for resolution bandwidth and video bandwidth depend on the selected
filter type. In addition, these settings have an impact on other measurement parame-
ters. The following equation shows the interdependency of these settings:
T
sweepMIN
= K*Span/RBW
2
where K = Filter constant
By default, a Gaussian filter is used. The resolution bandwidth, the video bandwidth
and the sweep time are set automatically according to the set span, and default cou-
pling is used. Thus, the following settings are applied:
RBW = 100 * Span
VBW = RBW = 100 * Span
Sweep time = T
min
for set Span, RBW, VBW
When defining the bandwidth and filter settings, consider the impact of the individual
settings on the other settings and the measurement result, as described in more detail
in the following sections.
● Separating Signals by Selecting an Appropriate Resolution Bandwidth ...............403
● Smoothing the Trace Using the Video Bandwidth ................................................ 404
● Coupling VBW and RBW ...................................................................................... 404
Bandwidth, Filter and Sweep Configuration