National Instruments NI Spectral Measurements Toolkit - Manual (Page 33)

© National Instruments Corporation 33 NI Spectral Measurements Toolkit User Guide
Figure 12 illustrates a typical ACP measurement and the three parameters
that specify the channels.
Figure 12. ACP Measurement
Occupied Bandwidth (OBW)
The SMT Occupied Bandwidth VI, located on the SMT Measurements
palette, returns the bandwidth of the frequency band that contains a
specified percentage of the total power of the signal. For a specified
percentage B, the upper and lower limits of the frequency band are the
frequencies above and below which (100 – B)/2% of the total power is
found. This measurement is sometimes known as the 99% bandwidth
because B = 99 is the most common input value. Use this VI before using
the SMT Spectrum Unit Conversion VI.
The SMT Occupied Bandwidth VI is appropriate only for single-channel
measurements, such as measurements on signals limited to a single
frequency band. For multiple-channel measurements, perform each
single-channel measurement separately.