Tuner doesn’t present the correct Gamma when tuning

June 12, 2024

Tuner Calibration

Symptoms / Solutions:

Possible symptoms include:

  • The back-to-back verification doesn’t return a transducer gain of 0 dB.
  • The verification of the tuner cal using VNA doesn’t return correct gamma values.

Proposed solutions:

  • The frequency step size of the VNA calibration should be chosen such that the frequencies of the tuner calibration are explicitly calibrated. When the tuner calibration frequency is not explicitly calibrated in the VNA cal, the VNA performs interpolation which results in wrong tuner calibration data or the VNA may turn off correction altogether.

Additional Information:

Once the VNA error correction is ON, it applies interpolation when there is a change in stimulus settings such as frequency step size during the active measurements.

Keywords: Tuner calibration, VNA calibration, tuning error

Last date modified:  February 22, 2017