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UHFQA

Just like the driver for the HDAWG in the previous example, we now use the tk.UHFQA instrument driver.

import numpy as np
import matplotlib.pyplot as plt

import qcodes as qc
import zhinst.qcodes as ziqc

uhfqa = ziqc.UHFQA("qa1", "dev2266", interface="1gbe", host="10.42.0.226")

Successfully connected to data server at 10.42.0.2268004 api version: 6
Successfully connected to device DEV2266 on interface 1GBE
Connected to: Zurich Instruments UHFQA (serial:dev2266, firmware:65939) in 1.02s

print([k for k in uhfqa.submodules.keys()])
print([k for k in uhfqa.parameters.keys()])

['channels', 'awg', 'stats', 'oscs', 'triggers', 'status', 'dios', 'auxins', 'system', 'sigins', 'sigouts', 'features', 'auxouts', 'qas']
['IDN', 'crosstalk_matrix', 'result_source', 'integration_time', 'averaging_mode', 'clockbase']

AWG core of the UHFQA

Also the UHFQA features one AWG Core.

print([k for k in uhfqa.awg.parameters.keys()])

['outputs', 'output1', 'output2', 'gain1', 'gain2']

Readout channels of the UHFQA

The UHFQA comes with signal processing streams for up to ten channels in parallel. The settings for the readout are grouped by channel in a list of all ten channels. Each item in the channels property of the UHFQA is an Instrument Channel that represent the signal processing path for one of the ten channels.

print([k for k in uhfqa.channels[0].parameters.keys()])

['rotation', 'threshold', 'readout_frequency', 'readout_amplitude', 'phase_shift', 'result', 'enabled']

Each of the channels follows the following signal processing steps:

1. Demodulation of the input signal

2. Rotation in the complex plane

3. Thresholding for binary result values

The values for the rotation and thresholding stages can be set using the rotation and threshold parameter of the channel.

The standard mode for the demodulation of input signals is the weighted integration mode. This corresponds to setting the integration weights for the two quadratures of the input signal to oscillate at a given demodulation frequency. When enabling the weighted integration with ch.enable(), the integration weights for the two quadratures are set. The demodulation frequency is set to the parameter readout_frequency.

Enabling weighted integration for the first four channels of the UHFQA and setting their demodulation frequency could look like this:

freqs = [85.6e6, 101.3e6, 132.8e6]

for ch in uhfqa.channels[:3]:
    ch.enable()
    ch.readout_frequency(freqs[ch.index])

The resut vector of each channel can be retrieved from the instrument by calling the read-only parameter result.

print(uhfqa.channels[0].result.__doc__)

Node: qas/0/result/data/0/wave
Description: Returns the result vector of the readout channel.
Type: Numpy array
Properties: Read
Unit: None


Parameter class:

* `name` result
* `label` Result
* `unit` None
* `vals` None

Readout parameters

There are readout parameters taht are not specific to one isngle channel but affect all ten readout channels. These are

• the integration_time: the time in seconds used for integrating the input signals

• the result_source lets the user select at which point in the signal processing path the result value should be taken

• the averaging_mode specifies if the hardware averages on the device should be taken in a sequential or cyclic way

• the crosstalk_matrix specifies a 10 x 10 matrix that can be calibrated to compensate for crosstalk betweeen the channels

These three parameters are attributes of the UHFQA instrument driver.

print(uhfqa.integration_time.__doc__)

The integration time used for demodulation in seconds. Can be up to 2.27 us when using weighted integration and up to 50 us in spectroscopy mode.

Parameter class:

* `name` integration_time
* `label` Integration Time
* `unit`
* `vals` <Numbers 0<=v<=5e-05>

print(uhfqa.result_source.__doc__)

The signal source for QA Results. Has to be one of ['Crosstalk', 'Integration', 'Threshold', 'Crosstalk Correlation', 'Threshold Correlation', 'Rotation'].

Parameter class:

* `name` result_source
* `label` Result Source
* `unit`
* `vals` <Enum: {'Crosstalk', 'Threshold', 'Threshold Correlation', 'Crosstalk Correlation', 'Integration', 'Rotation'}>

print(uhfqa.averaging_mode.__doc__)

Selects the order of the result logger. One of {'Cyclic', 'Sequential'}.

Parameter class:

* `name` averaging_mode
* `label` Averaging Mode
* `unit`
* `vals` <Enum: {'Sequential', 'Cyclic'}>

print(uhfqa.crosstalk_matrix.__doc__)

The 10x10 crosstalk suppression matrix that multiplies the 10 signal paths. Can be set only partially.

Parameter class:

* `name` crosstalk_matrix
* `label` Crosstalk Matrix
* `unit`
* `vals` None

Other important readout parameters can be accessed through the nodetree, for example the

• result length: the number of points to acquire

• result averages: the number of hardware averages

print(uhfqa.qas[0].result.length.__doc__)

* `Node`: /DEV2266/QAS/0/RESULT/LENGTH
* `Description`: The time duration of each capture in samples. A maximum of 4096 samples can be captured, which corresponds to 2.3 µs.
* `Properties`: Read, Write, Setting
* `Type`: Integer (64 bit)
* `Unit`: None


Parameter class:

* `name` length
* `label` length
* `unit`
* `vals` None

print(uhfqa.qas[0].result.averages.__doc__)

* `Node`: /DEV2266/QAS/0/RESULT/AVERAGES
* `Description`: log2 of the number of averages to perform, i.e. 0 means no averaging, 1 means 2 values are averaged, etc. Maximum setting is 15 meaning 2^15 values are averaged.
* `Properties`: Read, Write, Setting
* `Type`: Integer (64 bit)
* `Unit`: None


Parameter class:

* `name` averages
* `label` averages
* `unit`
* `vals` None

Arm the UHFQA readout

The arm(...) method of the UHFQA prepares the device for data acquisition. It enables the Results Acquisition and resets the acquired points to zero. This should be done before every measurement. The method also includes a shortcut to setting the values result length and result averages. They can be specified as keyword arguments. If the keyword arguemnts are not specified, nothing is changed.

uhfqa.arm(length=1e3, averages=2**5)

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