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7-23
PIM-P Analyzer User’s Manual
Copyright AWT-Global, LLC. All rights reserved.
7.3.2.4 SPU Time
Advanced Mode Only.
SPU (Soft Power-Up) gradually ramps up the RF
output power, starting from 20dBm, to the actual power
level. When the PIM-P amplifiers switch the RF Power
on, the full power is practically immediately present at
the RF Port. Depending on the DUT, this can sometimes
cause strong reflections. Antennas which are directly
(only with a short cable) connected to the RF port of the PIM-P are prone to such
reflections. If the returned energy is too high, PIM-P will switch off to protect its hardware.
A remedy is to simply increasing RF power gradually.
SPU Time: Increments 1s, Settings range 0sec to 60sec
Default: 0s
Example: With a power setting for 43dBm and SPU of 10s it takes 10 seconds to ramp
RF power up from 20dBm to 43dBm
Note: PIM-P starts measuring immediately after RF power is present at the RF
Port. During the period power is ramping up, PIM measurements are lower than the
ones at the final power level. Remember, PIM is measured in dBc – power relative to
the carrier: Lower carrier power equals lower PIM readings.
To ensure users do not misinterpret a “good” reading during power ramp-up, a blinking
“SPU” marker is shown during the time. Measurements should not be considered valid
when the red SPU indicator is flashing. Please wait for this indicator to disappear before
considering the measurement valid.