Rohde & Schwarz FPL1000 Series, Руководство пользователя

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The Spectrum Application (RF Measurements)
R&S
®
FPL1000
390 User Manual 1178.3370.02 ─ 03
7.6 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 .............................................390
● Bandwidth, Filter and Sweep Settings .................................................................. 395
● Reference: List of Available RRC and Channel Filters ......................................... 403
7.6.1 Impact of the Bandwidth, Filter and Sweep Settings
The bandwidth, filter and sweep settings are closely related and interdependent. 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
MIN
= 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 ...............390
● Smoothing the Trace Using the Video Bandwidth ................................................ 391
● Coupling VBW and RBW ...................................................................................... 392
● Coupling Span and RBW ...................................................................................... 392
● How Data is Measured: the Sweep Type ..............................................................393
● Which Data May Pass: Filter Types ......................................................................394
● How Long the Data is Measured: Sweep Time ....................................................394
● How Much Data is Measured: Sweep Points and Sweep Count .......................... 395
● How Often Data is Measured: Sweep Mode .........................................................395
7.6.1.1 Separating Signals by Selecting an Appropriate Resolution Bandwidth
The resolution bandwidth defines the 3 dB bandwidth of the resolution filter to be used.
An RF sinusoidal signal is displayed according to the passband characteristic of the
resolution filter (RBW), i.e. the signal display reflects the shape of the filter.
A basic feature of a signal analyzer is being able to separate the spectral components
of a mixture of signals. The resolution at which the individual components can be sepa-
Bandwidth, Filter and Sweep Configuration