Distortion suppression in radio frequency signal generators

A system, comprising:

• a quantum processor comprising at least one quantum bit;
• an arbitrary waveform generator comprising at least one arbitrary waveform generator channel configured to convert a baseband signal to a radio frequency control signal which controls the at least one quantum bit, wherein the at least one arbitrary waveform generator channel comprises:
• a plurality of signal paths;
• and
• a signal combiner;
• wherein the plurality of signal paths are configured to operate in parallel to convert the baseband signal to a plurality of radio frequency signals, wherein each signal path of the plurality of signal paths outputs a respective one of the plurality of radio frequency signals;
• and
• wherein the signal combiner is configured to combine the plurality of radio frequency signals to cancel corresponding distortion components in the plurality of radio frequency signals, and output a resulting radio frequency output signal as the radio frequency control signal, which comprises at least one suppressed distortion component.

A device, comprising:

• a radio frequency signal generator which comprises:
• a first signal path;
• a second signal path;
• and
• a signal combiner;
• wherein the first signal path and the second signal path are configured to operate in parallel to convert a baseband signal to a first radio frequency signal which is output from the first signal path, and a second radio frequency signal which is output from the second signal path;
• and
• wherein the signal combiner is configured to combine the first radio frequency signal and the second radio frequency signal to cancel corresponding third-order harmonic frequency components of a baseband signal frequency in the first radio frequency signal and the second radio frequency signal, and output a resulting radio frequency output signal in which the third-order harmonic frequency components of the baseband signal frequency is substantially suppressed.

A method, comprising:

• calibrating a radio frequency signal generator to convert a baseband signal to a radio frequency control signal, wherein calibrating the radio frequency signal generator comprises:
• calibrating a first signal path of the radio frequency signal generator to operate with a first current density;
• operating the first signal path to convert the baseband signal to a first radio frequency signal;
• analyzing the first radio frequency signal to determine a signal level of a target harmonic component in the first radio frequency signal;
• calibrating a second signal path of the radio frequency signal generator to operate with a second current density, which is less than the first current density;
• operating the second signal path to convert the baseband signal to a second radio frequency signal;
• analyzing the second radio frequency signal to determine a signal level of the target harmonic component in the second radio frequency signal;
• determining a difference between the signal levels of the target harmonic components in the first radio frequency signal and the second radio frequency signal;
• and
• in response to determining that the difference between the signal levels of the target harmonic components in the first radio frequency signal and the second radio frequency signal exceeds a specified threshold, recalibrating a second signal path of the radio frequency signal generator to adjust the second current density to equalize signal levels of the target harmonic components in the first radio frequency signal and the second radio frequency signal.