Use the following guidelines when configuring your measurements to achieve the best results.

All Measurement Types

  • Lock your source and analyzer to a common reference.
  • Match your reference accuracy to the most sensitive instrument—When using an external reference, ensure that the accuracy of the reference is suitable for your most sensitive or demanding instrument. Failure to do so can lead to lost or incorrect results.
  • Set the reference level just above the maximum power level expected in your measurement, but no higher—Setting the reference level too low causes inaccurate results due to distortion products in the instrument signal chain. Setting the reference level too high decreases instrument sensitivity and dynamic range.
  • Manually adjust the attenuation to an appropriate amount for your measurement—An improper attenuation setting can cause measurement errors. Low power signals might fall below the automatic attenuation setting, decreasing dynamic range.
  • Use an appropriate resolution bandwidth (RBW)—Using a more narrow RBW setting can help resolve lower power signals and distinguish signal shapes. However, a more narrow RBW setting increases measurement times.
  • Use averaging when appropriate—Applying averaging to your measurement increases measurement repeatability and helps identify signals close to the noise floor. However, averaging increases measurement times.

Channel Power Measurements

  • Set the RBW small enough to precisely define the channel bandwidth, but no smaller—Setting the RBW too large relative to the channel bandwidth causes power to be improperly applied across channels.
  • Use noise correction—Signals measured near the noise floor can be obscured by the inherent noise of the device. Enable SFP Noise Correction to improve your measurement.
  • Use the internal preamplifier to increase dynamic range for low power signals—To enable the internal preamplifier in the SFP, press the Amptd key, navigate to the second page of the softkey menu, and press the Internal Preamp softkey.

Third-Order Intercept (TOI) Measurements

  • Calculate the maximum power using the sum of the two signals—In a two-tone test, the maximum expected power is cumulative.
  • Adjust the attenuation to an appropriate amount—The internal distortion of the analyzer can cause measurement inaccuracies if insufficient attenuation is applied.