Keysight Technologies N9321C, User Manual

Page: 49 / 220

41
Functions and Measurements
Measuring Multiple Signals
Resolving Small Signals Hidden by Large Signals
This example uses narrow resolution bandwidths to resolve two RF
signals that have a frequency separation of 50 kHz and an
amplitude difference of 60 dB.
1 Connect two sources to the
RF IN
as shown in Figure 3-4 .
2 Set one source to 300 MHz at –10 dBm. Set the other source to
300.05 MHz at –70 dBm.
3 Set the analyzer as follows:
Press
Preset
. (With
Preset Type
of
DFT
)
Press
Frequency > 300 > MHz
Press
BW > 30 > kHz
Press
Span > 500 > kHz
4 Set the 300 MHz signal to the reference level:
Press
Peak Search
Press
Marker > Marker To > To Reference
NOTE
The 30 kHz filter shape factor of 15:1 has a bandwidth of 450 kHz at the 60
dB point. The half-bandwidth (225 kHz) is NOT narrower than the frequency
separation of 50 kHz, so the input signals can not be resolved.