Contour method to shift the calibrated region of source/load pull tuners in power amplifier characterization

In this paper, a shifting method of the calibrated region of passive source/load pull tuners by choosing accessories´ S-parameters in the source/load pull tuner system is introduced. To increase Γ of the passive source/load pull tuner at DUT reference plane in a target region of Smith chart, the calibrated region of the tuner can be shifted intentionally to the desired region by choosing the accessories in the tuner system, such as bias tee, directional coupler, isolator and attenuator with considering the phase and magnitude of their S-parameters. The shifting mechanism on calibrated region of passive source/load pull tuner of these accessories is analyzed. Based on this analysis, we could choose the accessories to shift intentionally the calibrated region of tuner to the target region and increase the maximum Γ.