Performance Limits and Cryogenic Characterization of a 13-to-18 GHz CMOS Reflective Type Phase Shifter for Qubit Control

This paper investigates whether a reflective type phase shifter (RTPS) meets the signal requirements for qubit control. First, the precision limits of the RTPS at room temperature are investigated, achieving a record low 0.01° RMS error and 0.06° maximum absolute error across the 13-to-18 GHz band using single tone phase shifting. Subsequently, the device is characterized at cryogenic temperatures (4K) to evaluate its suitability for qubit control. At 4K, the RTPS achieves a minimum RMSE of 0.23°, with a maximum absolute error of 1.8°. The largest phase deviations occur near the estimated flatband voltage, suggesting a contribution from random field-assisted ionization. An analysis of the performance degradation at cryogenic temperatures is provided.