S-Parameter, Gamma Correction and Real Time Measurement Uncertainty
Application Notes
When performing radio frequency (RF) power measurements, it is important to accurately estimate the uncertainty of the measurements. One of the major sources of uncertainty for power measurements is the mismatch error due to the reflections between the device under test (DUT) and the power sensor. Due to these reflections not all of the power is transferred or absorbed by the power sensor for accurate power measurement. This mismatch error can be corrected by knowing the phase and magnitude of the sensor’s and DUT’s reflection coefficients, Γ L and Γ G respectively. The Keysight Technologies, Inc. U8480 Series USB thermocouple power sensor with the new gamma correction function allows users to input a DUT reflection coefficient (with both magnitude and phase) to correct for the mismatch error.