Troubleshooting Hints - Keysight X Series Measurement Manual

Measuring Digital Communications Signals
Spurious Emissions Measurements

Troubleshooting hints

Spurious emissions measurements can reveal the presence of degraded or defective
parts in the transmitter section of the UUT. The following are examples of problems
which, once indicated by testing, may require further attention:
• Faulty DC power supply control of the transmitter power amplifier
• RF power controller of the pre-power amplifier stage
• I/Q control of the baseband stage
• Reduction in the gain and output power level of the amplifier due to a degraded
• Degradation of amplifier linearity and other performance characteristics
Power amplifiers are one of the final stage elements of a base transmitter and play a
critical part in meeting the important power and spectral efficiency specifications.
Measuring the spectral response of these amplifiers to complex wideband signals is
crucial to linking amplifier linearity and other performance characteristics to the
stringent system specifications.
gain control and/or increased distortion
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