Keysight Technologies N9340B, User Manual

Page: 59 / 172

Making Measurements
Making Distortion Measurements
53
After the performance of the source/analyzer
combination has been verified, the DUT (device under
test, for example, an amplifier) would be inserted
between the directional coupler output and the analyzer
input.
2 Set one source (signal generator) to 300 MHz and the
other source to 301 MHz. This will define the
frequency separation at 1 MHz. Set both sources
equal in amplitude, as measured by the analyzer. In
this example, they are both set to –5 dBm.
3 Set the analyzer center frequency and span:
• Press [PRESET] (Factory preset)
• Press [FREQ] > 300.5 > {MHz}
• Press [SPAN] > 5 > {MHz}
4 Reduce the RBW until the distortion products are
visible:
• Press [BW/SWP] > {RBW}, and reduce the RBW
using the knob, the arrow keys or the numeric key-
pad.
5 Move the signal to the reference level:
• Press [MARKER] > {Peak Search}
• Press [MARKER] > {Marker To} > {To Ref}
6 Reduce the RBW until the distortion products are
visible:
• Press [BW/SWP] > {RBW}, and reduce the RBW
using the knob, the arrow keys or the numeric key-
pad.
7 Activate the second marker and place it on the peak
of the distortion product (beside the test signal) using
the Next Peak:
• Press [MARKER] > {Delta}
NOTE
The coupler used should have a high isolation between the
two input ports to limit the sources intermodulation.