Pump signal generation circuit, power testing device, and superconducting quantum computer

Abstract

The utility model provides a kind of PUMP signal generation circuit, power testing device and superconducting quantum computer, the PUMP signal generation circuit includes: variable gain amplifier, target frequency source signal generation branch, signal processing unit, digital-analog converter, directional coupler, fixed attenuator, detector and analog-digital converter;The technical scheme of the present application significantly suppresses the power fluctuation caused by temperature drift, can realize the power of output PUMP signal in a predetermined dynamic range at different temperatures, so as to achieve the purpose of improving the power stability of output PUMP signal.

Description

Technical Field

[0001] This invention belongs to the field of quantum computing technology and relates to a PUMP signal generation circuit, a power testing device, and a superconducting quantum computer. Background Technology

[0002] A pump signal is a signal that provides energy or control commands. In a superconducting quantum computer, the pump signal drives the parametric amplifier in the readout circuit, serving as the energy input for signal amplification. Changes in the pump signal alter the amplifier's gain, thus requiring the pump signal output power to remain at a stable level.

[0003] Existing design solutions such as Figure 1 As shown, the host computer 10 sends the target parameters to the signal processing unit 11. The signal processing unit 11 controls the phase-locked loop 12 to generate the target frequency source signal. After being filtered by the filter 13, the signal is sent to the variable gain amplifier 14 for signal amplification and output, and finally outputs the target PUMP signal. At the same time, the signal processing unit 11 controls the digital-to-analog converter (DAC) 15 to output the target voltage to realize the gain adjustment of the variable gain amplifier 14.

[0004] The power stability of the PUMP signal output by the existing PUMP signal generation circuit is related to the characteristics of the devices. The phase-locked loop 12 and the variable gain amplifier 14 are both active devices. When the temperature changes, the output power of the PUMP signal will inevitably change. The power stability of the output PUMP signal will greatly affect the gain performance of the parametric amplifier (TWPA), thereby affecting the read fidelity. Utility Model Content

[0005] The technical solution of this utility model is used to solve the problem of how to generate a stable PUMP signal.

[0006] This utility model solves the above-mentioned technical problems through the following technical solution:

[0007] This utility model provides a PUMP signal generation circuit, including: a variable gain amplifier, a target frequency source signal generation branch, and a feedback adjustment branch; the feedback adjustment branch includes: a signal processing unit, a digital-to-analog converter, a directional coupler, a fixed attenuator, a detector, and an analog-to-digital converter.

[0008] The signal processing unit is connected to the input terminal of the target frequency source signal generation branch, and the output terminal of the target frequency source signal generation branch is connected to the first input terminal of the variable gain amplifier.

[0009] The input terminal of the digital-to-analog converter (DAC) is connected to the signal processing unit, the output terminal of the DAC is connected to the second input terminal of the variable gain amplifier, the input terminal of the directional coupler is connected to the output terminal of the variable gain amplifier, the first output terminal of the directional coupler serves as the PUMP signal output terminal, the second output terminal of the directional coupler is connected to the input terminal of the fixed attenuator, the output terminal of the fixed attenuator is connected to the input terminal of the detector, the output terminal of the detector is connected to the input terminal of the analog-to-digital converter (ADC), and the output terminal of the ADC is connected to the signal processing unit.

[0010] Furthermore, the target frequency source signal generation branch includes a phase-locked loop (PLL) and a filter. The input terminal of the PLL is connected to the signal processing unit, the output terminal of the PLL is connected to the input terminal of the filter, and the output terminal of the filter is connected to the first input terminal of the variable gain amplifier.

[0011] Furthermore, the feedback regulation branch also includes a temperature monitoring unit, the output of which is connected to the signal processing unit.

[0012] Furthermore, the feedback adjustment branch also includes a memory, which is connected to the signal processing unit.

[0013] Furthermore, the signal processing unit is also connected to a host computer.

[0014] Preferably, the temperature monitoring unit employs a temperature sensor.

[0015] This utility model also provides a power testing device applied to the above-mentioned PUMP signal generation circuit, including: a power meter, wherein the power meter is connected to the PUMP signal output terminal of the PUMP signal generation circuit.

[0016] Furthermore, the power testing device also includes a high and low temperature chamber, and the PUMP signal generation circuit is placed in the high and low temperature chamber.

[0017] This invention also provides a superconducting quantum computer, wherein the PUMP signal input terminal of the superconducting quantum computer is connected to the PUMP signal output terminal of the aforementioned PUMP signal generation circuit. Attached Figure Description

[0018] Figure 1 This is a structural diagram of a PUMP signal generation circuit in the prior art;

[0019] Figure 2 This is a structural diagram of the PUMP signal generation circuit according to Embodiment 1 of this utility model;

[0020] Figure labeling: 10-Host computer, 11-Signal processing unit, 12-Phase-locked loop, 13-Filter, 14-Variable gain amplifier, 15-Digital-to-analog converter, 16-Directional coupler, 17-Fixed attenuator, 18-Detector, 19-Analog-to-digital converter, 20-Temperature monitoring unit, 21-Memory;

[0021] The abbreviations in the attached diagram are explained as follows: DAC - Digital-to-Analog Converter, ADC - Analog-to-Digital Converter. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below in conjunction with the embodiments of this utility model. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0023] The technical solution of this utility model will be further described below with reference to the accompanying drawings and specific embodiments:

[0024] Example 1

[0025] like Figure 2 As shown, this embodiment provides a PUMP signal generation circuit, which includes a signal processing unit 11, a phase-locked loop 12, a filter 13, a variable gain amplifier 14, a digital-to-analog converter 15, a directional coupler 16, a fixed attenuator 17, a detector 18, an analog-to-digital converter 19, a temperature monitoring unit 20, and a memory 21. The digital-to-analog converter (DAC) 15, directional coupler 16, fixed attenuator 17, detector 18, analog-to-digital converter (ADC) 19, signal processing unit 11, temperature monitoring unit 20, and memory 21 constitute a feedback adjustment branch, while the phase-locked loop 12 and filter 13 constitute a target frequency source signal generation branch.

[0026] The connection relationships of the various components in the PUMP signal generation circuit of this embodiment are as follows:

[0027] The signal processing unit 11 is connected to the input terminal of the phase-locked loop 12. The output terminal of the phase-locked loop 12 is connected to the input terminal of the filter 13. The output terminal of the filter 13 is connected to the first input terminal of the variable gain amplifier 14. The output terminal of the variable gain amplifier 14 is connected to the input terminal of the directional coupler 16. The first output terminal of the directional coupler 16 outputs a PUMP signal. The second output terminal of the directional coupler 16 is connected to the input terminal of the fixed attenuator 17. The output terminal of the fixed attenuator 17 is connected to the input terminal of the detector 18. The output terminal of the detector 18 is connected to the input terminal of the analog-to-digital converter 19. The output terminal of the analog-to-digital converter 19 is connected to the signal processing unit 11. The signal processing unit 11 is also connected to the input terminal of the digital-to-analog converter 15. The output terminal of the digital-to-analog converter 15... The input terminal is connected to the second input terminal of the variable gain amplifier 14; the feedback adjustment branch includes a directional coupler 16, a fixed attenuator 17, a detector 18, an analog-to-digital converter 19, a signal processing unit 11, and a digital-to-analog converter 15; the feedback adjustment branch also includes a temperature monitoring unit 20 and a memory 21. The temperature monitoring unit 20 is used to measure the real-time temperature value of the PUMP signal generation circuit. The memory 21 stores calibration coefficients. The output terminal of the temperature monitoring unit 20 is connected to the signal processing unit 11, and the measured temperature value is input to the signal processing unit 11. The memory 21 is connected to the signal processing unit 11. The signal processing unit 11 is pre-configured with target parameters, or the signal processing unit 11 is connected to the host computer 10 via a serial port to obtain the target parameters.

[0028] The working principle of the PUMP signal generation circuit in this embodiment is as follows:

[0029] The signal processing unit 11 is pre-configured with target parameters, or the target parameters are sent to the signal processing unit 11 (e.g., an FPGA) via the host computer 10. The signal processing unit 11 controls the phase-locked loop 12 to generate the target frequency source signal. After being filtered by the filter 13, the signal is sent to the variable gain amplifier 14 for signal power amplification. The amplified signal is split into two paths by the directional coupler 16. One path directly outputs the PUMP signal, and the other path is sent to the fixed attenuator 17 in the feedback adjustment branch. After the signal is power-adjusted by the fixed attenuator 17, it is sent to the detector 18. The fixed attenuator 17 is used to ensure that the signal power entering the detector 18 is within a suitable range. The detector 18 outputs a detection signal. The voltage is fed to the analog-to-digital converter 19, which acquires the voltage signal and sends it to the signal processing unit 11 to calculate the real-time output power as the detection power. The temperature monitoring unit 20 acquires the real-time temperature value of the circuit and sends it to the signal processing unit 11. Combined with the calibration coefficients pre-stored in the memory 21, the signal processing unit 11 calculates the calibration voltage. The calibration voltage is compared with the target parameters to obtain the control voltage of the digital-to-analog converter 15, which is then input to the variable gain amplifier 14. The amplification gain of the variable gain amplifier 14 is adjusted to change the power of the output PUMP signal, thereby achieving closed-loop feedback and improving the power stability of the output PUMP signal.

[0030] The formula for calculating the calibration voltage is as follows:

[0031] V c =P det +k*T

[0032] Among them, V c P represents the calibration voltage. det denoted by , k represents the calibration coefficient, and T represents the temperature value.

[0033] Preferably, the temperature monitoring unit 20 can be a temperature sensor.

[0034] The method for obtaining the calibration coefficients pre-stored in memory 21 is as follows:

[0035] 1) Place the entire PUMP signal generation circuit in a high and low temperature chamber, connect the first output terminal of the directional coupler 16 to a power meter, and test the power of the output PUMP signal at a standard temperature (e.g., 25°C).

[0036] 2) Change the temperature, and at the same time, the host computer 10 adjusts the control voltage of the digital-to-analog converter 15 to ensure that the power of the output PUMP signal is consistent with the power of the output PUMP signal at the standard temperature. Record the detection voltage output by the detector 18 at this time and convert it into detection power.

[0037] 3) Repeat step 2) to obtain the detection power recorded under different temperature conditions, and use the detection power recorded under different temperature conditions to perform linearity fitting to calculate the calibration coefficient, and save it in memory 21.

[0038] The PUMP signal generation circuit in this embodiment dynamically adjusts the amplification gain of the signal by controlling the output voltage of the feedback adjustment branch, receives the output PUMP signal, compares it with the set target parameters, completes gain control, and realizes closed-loop feedback of PUMP signal power. This allows the output PUMP signal power to be stabilized within a predetermined dynamic range at different temperatures.

[0039] Test

[0040] 1. The power test of the PUMP signal output by the existing PUMP signal generation circuit is as follows:

[0041] The entire PUMP signal generation circuit was placed in a high and low temperature chamber. The output of the variable gain amplifier 14 was connected to a power meter. The power of the output PUMP signal was tested at different temperatures. The specific test data are shown in Table 1 below.

[0042] Table 1. Power Test Table of Existing Circuit Output PUMP Signal

[0043]

[0044] As can be seen from Table 1, as the temperature increases, the power of the PUMP signal output by the existing PUMP signal generation circuit gradually decreases, showing a roughly linear decreasing trend. Within the temperature range of -10 to 50℃, the maximum fluctuation of the power is 4.36dBm.

[0045] 2. The power test of the PUMP signal output by the PUMP signal generation circuit in this embodiment is as follows:

[0046] The entire PUMP signal generation circuit was placed in a high and low temperature chamber. The first output terminal of the directional coupler 16 was connected to a power meter. The power of the output PUMP signal was tested at different temperatures. The specific test data are shown in Table 2 below.

[0047] Table 2 Power Test Table of PUMP Signal Output in this Embodiment

[0048]

[0049] As can be seen from Table 2, as the temperature increases, the power fluctuation of the output PUMP signal of the PUMP signal generation circuit in this embodiment is randomly distributed. Within the temperature range of -10 to 50℃, the maximum power fluctuation is 0.16dBm. Compared with the PUMP signal generation circuit of the prior art, the power stability index of the output PUMP signal of the PUMP signal generation circuit in this embodiment is greatly improved.

[0050] Example 2

[0051] This embodiment provides a superconducting quantum computer, wherein the PUMP signal input terminal of the superconducting quantum computer is connected to the PUMP signal output terminal of the PUMP signal generation circuit in Embodiment 1.

[0052] The above embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this utility model.

Claims

1. A PUMP signal generation circuit, characterized in that, include: Variable gain amplifier (14), target frequency source signal generation branch and feedback adjustment branch; The feedback regulation branch includes: a signal processing unit (11), a digital-to-analog converter (15), a directional coupler (16), a fixed attenuator (17), a detector (18), and an analog-to-digital converter (19); The signal processing unit (11) is connected to the input terminal of the target frequency source signal generation branch, and the output terminal of the target frequency source signal generation branch is connected to the first input terminal of the variable gain amplifier (14). The input terminal of the digital-to-analog converter (15) is connected to the signal processing unit (11), the output terminal of the digital-to-analog converter (15) is connected to the second input terminal of the variable gain amplifier (14), the input terminal of the directional coupler (16) is connected to the output terminal of the variable gain amplifier (14), the first output terminal of the directional coupler (16) serves as the PUMP signal output terminal, the second output terminal of the directional coupler (16) is connected to the input terminal of the fixed attenuator (17), the output terminal of the fixed attenuator (17) is connected to the input terminal of the detector (18), the output terminal of the detector (18) is connected to the input terminal of the analog-to-digital converter (19), and the output terminal of the analog-to-digital converter (19) is connected to the signal processing unit (11).

2. The PUMP signal generation circuit according to claim 1, characterized in that, The target frequency source signal generation branch includes a phase-locked loop (12) and a filter (13). The input terminal of the phase-locked loop (12) is connected to the signal processing unit (11), the output terminal of the phase-locked loop (12) is connected to the input terminal of the filter (13), and the output terminal of the filter (13) is connected to the first input terminal of the variable gain amplifier (14).

3. The PUMP signal generation circuit according to claim 1, characterized in that, The feedback regulation branch also includes a temperature monitoring unit (20), the output of which is connected to the signal processing unit (11).

4. The PUMP signal generation circuit according to claim 1, characterized in that, The feedback adjustment branch further includes a memory (21), which is connected to the signal processing unit (11).

5. The PUMP signal generation circuit according to claim 1, characterized in that, The signal processing unit (11) is also connected to the host computer (10).

6. The PUMP signal generation circuit according to claim 3, characterized in that, The temperature monitoring unit (20) uses a temperature sensor.

7. A power testing device applied to the PUMP signal generation circuit according to any one of claims 1 to 6, characterized in that, include: A power meter is connected to the PUMP signal output terminal of a PUMP signal generation circuit.

8. The power testing device according to claim 7, characterized in that, Also includes: The PUMP signal generation circuit is placed inside the high and low temperature chamber.

9. A superconducting quantum computer, characterized in that, The PUMP signal input terminal of the superconducting quantum computer is connected to the PUMP signal output terminal of the PUMP signal generation circuit according to any one of claims 1 to 6.

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