IQ Mixer Calibration for Superconducting Circuits

TL;DR

This paper introduces calibration techniques for IQ mixers used in superconducting circuits, employing Kalman filters and frequency offsets to optimize performance without disassembly, suitable for complex quantum systems.

Contribution

It adapts wireless communication calibration methods for superconducting circuit IQ mixers, enabling in-situ, automated calibration with Kalman filters and frequency control.

Findings

Effective calibration of IQ mixers achieved

Calibration can be embedded in control electronics

Improves performance of superconducting quantum circuits

Abstract

An important device for modulation and frequency translation in the field of circuit quantum electrodynamics is the IQ mixer, an analog component for which calibration is necessary to achieve optimal performance. In this paper, we introduce techniques originally developed for wireless communication applications to calibrate upconversion and downconversion mixers. A Kalman filter together with a controllable carrier frequency offset calibrates both mixers without removing them from the embedding measurement infrastructure. These techniques can be embedded into room temperature control electronics and they will find widespread use as circuit QED devices continue to grow in size and complexity.