Specifications

Tips from the experts
Swept IMD sweep types
• Calibrate at all measurement frequencies or at center frequencies only, trading off
productivity and accuracy
• Let the PNA-X control external signal generators to greatly simplify swept IMD
measurements of mixers and converters
• Use the Marker to IM Spectrum feature to show the spectrum at a specified point
on the swept IMD trace
• Use point averaging with IM Spectrum, especially when using a wide resolution band-
width, to reduce the noise deviation of the noise floor with minimum speed impact
Calibrating all frequencies is recommended for wide tone spacing.
Although the calibration takes longer with “all frequencies”,
measurement speed is not affected.
The IM Spectrum in the lower window shows the spectrum
corresponding to the Swept IMD marker at the center of the
trace in the upper window. Point averaging is applied to
the IM Spectrum to reduce the noise deviation.
IMD and IP3 versus LO power yields maximum IP3 with lowest
possible LO drive power. This helps specify the mixer setup to
achieve maximum efficiency while minimizing power consumption.
Sweep fc Sweep Delta F Power Sweep CW LO Power Sweep Segments
Center
Frequency
Swept Fixed Fixed Fixed Fixed
Swept (as defined
by segment table)
Tone
Spacing
Fixed Swept Fixed Fixed Fixed Fixed
Tone
Powers
Fixed Fixed
Swept (coupled
or uncoupled)
Fixed Fixed Fixed
Diagram
Cal all frequencies
Cal center frequencies
Delta F
f1 f2
fc
Delta F
f1 f2
fc
Delta F
f1 f2
fc
Delta F
f1
f2
Delta F
f1 f2
fc
Delta F
f1 f2
fc
f1LO f2
fc
Delta F
f1 f2
fc
Delta F
f1 f2
fc
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