Calibration Properties¶

In this chapter, we give a short overview of all possible calibration properties that may be defined on a SignalCalibration and explain possible settings.

For a more in-depth introduction to how Calibration is used, please refer to the Instrument Calibration and Experiment Calibration chapters.

Oscillators¶

Property	relevant for	accepted values	short description
`oscillator`	HDAWG, UHFQA, SHFQA, SHFSG, SHFQC	`Oscillator` object with `frequency` and `modulation_type` specified	Defines the modulation frequency with which all waveforms played on this signal are modulated. Also determines if the modulation is done through a hardware feature or in software.
`local_oscillator`	SHFQA, SHFSG, SHFQC	`Oscillator` object with `frequency` specified	Defines center frequency of a pair of signal channels

Note

On the SHFSG and SHFQC, pairs of physical output channels may share the same local oscillator

Delays¶

Table 1: Delay Calibration Properties
Property	relevant for	accepted values	short description
port_delay	HDAWG, UHFQA (input lines only), SHFQA, SHFSG, SHFQC	times in seconds	For output lines: defines a delay for signals played on this channel For input lines: defines a delay between the start of the readout pulse playback and the start of the integration Implemented through hardware settings, has no effect on the pulse sheet.
delay_signal	HDAWG, UHFQA, SHFQA, SHFSG, SHFQC	times in seconds	Same as port_delay but implemented through shifting the playback in software. Will be visible in the pulse sheet

Delay Calibration Properties

Mixer Calibration¶

Property	relevant for	accepted values	short description
`mixer_calibration`	HDAWG (iq_signals only)	`MixerCalibration` object, which takes a list of `voltage_offsets` and a mixer `correction_matrix`	Sets offsets and a calibration matrix to compensate for imperfections in the up-conversion setup

Range¶

Property	relevant for	accepted values	short description
`range`	SHFQA, SHFSG, SHFQC	Power value in dBm	Sets the power range of the channel

Threshold¶

Table 2: Threshold Calibration Property
Property	relevant for	accepted values	short description
`threshold`	UHFQA (input lines only), SHFQA (input lines only)	real number	Sets the state discrimination threshold when using `AcquisitionType.DISCRIMINATION`

Port Mode¶

Property	relevant for	accepted values	short description
`port_mode`	SHFSG, SHFQC (output lines only)	Keyword 'RF' or 'LF'	Enables ('LF') or disables ('RF') the low frequency path on the up-conversion units

Real-time Precompensation¶

The real-time precompensation is available on HDAWG instruments with enabled HDAWG-PC option. It provides four different filters that can be configured in order to compensate for pulse distortions:

Exponential filters
Bounce compensation
High-pass compensation
FIR filter

For more information on the different filters, please refer to the corresponding chapter in the HDAWG manual.

In LabOne Q, the precompensation is enabled in the setup calibration by adding the following lines to the Calibration object:

precompensation = Precompensation(
    exponential= [
      ExponentialCompensation(timeconstant = 200e-9, amplitude = 0.5),
      ExponentialCompensation(timeconstant = 33e-9, amplitude = 0.7),
      ## ...
      ## up to 8 different filters
      ],
    high_pass = HighPassCompensation(timeconstant = 300e-9),
    bounce = BounceCompensation(delay = 5e-9, amplitude = 0.4),
    ## fir_coefs is an array containing all 40 coefficients
    FIR = FIRCompensation(coefficients = fir_coefs)
)

Property	relevant for	accepted values	short description
`precompensation`	HDAWG (with PC option enabled)	`Precompensation` object	Contains the various filters (`exponential`, `high_pass`, `bounce`, `FIR`) with the corresponding properties such as time constants, amplitudes and coefficients.

Precompensation filters can be enabled on signal lines of type iq_signal and rf_signal. In order to preserve the correct pulse timing, the high-pass compensation can only be enabled pair-wise on signal lines of type rf_signal that are mapped to the same AWG core.

Clearing the high-pass compensation filter¶

The I.I.R. high-pass filter requires regular clearing to avoid an output overflow. Typically, the clearing is done in between quantum experiments so the occurring voltage jump on the affected signal output does not interfere with the qubit. In LabOne Q, the high-pass filter can be cleared during a delay instruction, for example while the experiment is waiting for the readout resonator to relax. The delay time must be at least 32 samples (13.33 ns or 16 ns depending on the sampling rate):

exp.delay(signal="flux_line", time=500e-9, precompensation_clear=True)

Note, that the clearing of the high-pass filter is a control element, thus the containing section is padded to the sequencer grid (see the timing rules).