An adaptive tuning method for generating pulse-driven AC quantum voltage

Abstract

This paper proposes an adaptive tuning method for generating pulsed AC quantum voltages. This method aims to address the difficulty in determining the optimal parameter combination to maximize the quantum operating margin during quantum voltage generation. This method optimizes multiple parameters using an automated search algorithm. After optimization, a triangular wave is superimposed on the chip's bias terminals to measure and evaluate the operating margin of the pulsed AC quantum voltages and determine the optimal parameter settings that maximize the operating margin. This method can provide optimal system performance and stability in practical applications. Through systematic data acquisition and analysis, it ensures precise control and optimization of system performance, achieving optimal operating conditions in complex operating environments.

Description

Technical Field

[0001] The present invention belongs to the field of metrology, and in particular relates to an adaptive tuning method for generating a pulse-driven alternating current quantum voltage. Background Art

[0002] Synthesis of pulse-driven AC quantum voltages can be achieved by driving a Josephson junction array with a high-speed pulse train. This method boasts a pure signal spectrum and a wide bandwidth, making it valuable in precision measurement and other applications requiring high signal purity and stability. However, achieving spectrally pure, stable, and accurate AC quantum voltage synthesis places extremely high demands on the quality of the high-speed pulse train. The pulse amplitude, frequency, and phase characteristics must be precisely controlled to ensure proper driving of the Josephson junction array and generation of the desired voltage signal. Even slight deviations in device parameters can lead to distortion, noise, or other errors in the synthesized AC quantum voltage signal, directly impacting signal purity and stability. Furthermore, the synthesis system involves numerous devices and parameters requiring adjustment, such as the timing control of the pulse generator, the drive circuitry, the electrical characteristics of the amplifier, and the operating state of the Josephson junction array. The configuration and adjustment of these parameters are crucial to the overall system performance. Improper setting of any parameter can cause instability in the high-speed pulse train, thereby affecting the quantum state of the voltage signal. This interference not only degrades signal quality but can also cause errors in measurement and standardization. Therefore, to ensure the highest purity and accuracy of the generated AC quantum voltage signal, the high-speed pulse train generation process must be precisely controlled. This involves meticulous optimization and calibration of each device and parameter in the synthesis system to ensure optimal operation and avoid any potential interference or errors. Through this rigorous control and tuning, the advantages of pulse-driven AC quantum voltage technology can be maximized, providing a high-precision voltage standard and signal source. Summary of the Invention

[0003] This invention aims to address the shortcomings of the existing technology by proposing an adaptive tuning method for generating pulse-driven AC quantum voltage. This method optimizes multiple parameters through an automatic search algorithm. After optimization, a triangular wave is superimposed on the chip's bias terminal and the operating margin of the pulse-driven AC quantum voltage is measured to determine the optimal parameter settings that maximize the operating margin. This method exhibits excellent dynamics, intelligence, and robustness. Its core lies in dynamically adjusting parameters based on real-time data and feedback, rather than relying on fixed preset values. This feature enables the system to flexibly respond to environmental changes. Through a feedback control mechanism, the system can determine and adjust parameters in real time to ensure the array is in optimal operating condition.

[0004] The technical solutions of the present invention are as follows:

[0005] Step 1: Use a radio frequency arbitrary waveform generator to generate an arbitrary waveform signal pulse train with specific amplitude and frequency to drive the synthesis system;

[0006] Step 2: Determine the sampling rate of the ADC sampler based on the fundamental frequency of the AC quantum voltage signal to be synthesized, obtain the spectrum of the measured signal, and calculate its total harmonic distortion (THD) value;

[0007] Step 3: Using an automatic search algorithm based on the golden ratio, combined with the spectrum and THD results obtained in step 2, gradually adjust the amplitude and phase of the pattern generator, the gain of the amplifier, and the amplitude and phase of the compensation circuit until the THD value stabilizes and the spectrum characteristics meet the expected requirements.

[0008] Step 4: After completing parameter optimization, superimpose a triangular wave signal on the bias compensation terminal of the pulse-driven Josephson chip, gradually increasing the amplitude of the triangular wave until the noise floor in the signal spectrum becomes larger, harmonics appear, and the THD value increases and becomes unstable. Based on the amplitude of the triangular wave at this time, the quantum operating margin of the pulse-driven AC quantum voltage under the current parameter settings can be determined;

[0009] Step 5: Repeat steps 2 to 4 multiple times to construct a distribution curve of the relationship between the parameter to be adjusted and the quantum operating margin of the pulse-driven AC quantum voltage, and finally determine the optimal parameter setting that can maximize the quantum operating margin.

[0010] Specifically, the step 1 is achieved as follows:

[0011] A specific pulse train signal is generated using an RF arbitrary waveform generator. This pulse train is configured to adapt to the specified amplitude and frequency based on the synthesis requirements. By precisely controlling the pulse amplitude and phase of the RF arbitrary waveform generator, a flexible and stable excitation source is provided for the pulse-driven AC quantum voltage synthesis system.

[0012] The second step is achieved as follows:

[0013] According to the fundamental frequency of the AC quantum voltage signal to be synthesized, the sampling rate of the sampler is determined.

[0014] The collected time domain data is converted into frequency domain information through Fourier transform to generate a spectrum diagram of the measured signal. After obtaining the spectrum diagram, the total harmonic distortion (THD) value of the signal is further calculated.

[0015] The step three is achieved as follows:

[0016] When optimizing parameters using an automatic search algorithm based on the golden ratio, the system ensures that the THD value remains stable at a minimum while also ensuring that the spectral characteristics meet the desired requirements. During initialization, the search range for the device parameters to be adjusted is defined, and the golden ratio algorithm is used to efficiently search within the parameter space. The parameters are continuously adjusted, and after each adjustment, the signal spectrum is obtained and the THD value is calculated. The algorithm iteratively narrows the search range to approach the optimal parameter settings. Each adjustment updates the search strategy based on the THD value and spectrum evaluation results to ensure that the THD value is minimized and the spectral characteristics meet the desired requirements. The optimization process ends when the THD value stabilizes at its lowest point and the spectral characteristics meet the requirements.

[0017] The fourth step is achieved as follows:

[0018] After completing parameter optimization, a triangular wave with increasing amplitude is gradually applied to the bias compensation end of the pulse-driven Josephson chip. As the amplitude of the triangular wave gradually increases, the system will experience different operating states, eventually leading to the appearance of harmonics in the signal spectrum, that is, new frequency components appear in the spectrum.

[0019] During this process, the THD (total harmonic distortion) value will increase significantly and tend to be unstable. By accurately measuring and recording the amplitude of the triangle wave at this time, the quantum operating margin of the pulse-driven AC quantum voltage can be determined under the current parameter settings. This margin represents the stability range of the system under working conditions and the maximum excitation intensity it can withstand.

[0020] The step five is achieved as follows:

[0021] After the system completes initial optimization, steps two to four are repeated multiple times to establish a distribution curve of the relationship between the parameters to be adjusted and the quantum operating margin of the pulse-driven AC quantum voltage. The specific operations include repeatedly adjusting the device parameters, reacquiring the signal spectrum, and calculating the THD value. During each adjustment process, the triangular wave signal is superimposed on the bias compensation end of the pulse-driven Josephson chip, and the amplitude of the triangular wave is gradually increased until a significant increase in harmonic phenomena and THD values ​​is observed.

[0022] By iterating this process multiple times, a series of experimental data on the relationship between parameter configurations and quantum operating margins are generated, and a distribution curve of the relationship between parameters and quantum operating margins is plotted. This curve details the impact of different parameter settings on the system operating margin. This relationship distribution curve not only reveals the specific impact of each parameter on system performance, but also helps identify the optimal parameter configuration, that is, the setting that maximizes the quantum operating margin among all tested parameters.

[0023] In summary, analysis of the relationship distribution curves identifies the optimal parameter combination that maximizes the quantum operating margin. This optimal setting delivers optimal system performance and stability in practical applications, providing a scientific basis for the design and optimization of pulse-driven AC quantum voltage synthesis systems. This approach, through systematic data acquisition and analysis, ensures precise control and optimization of system performance, achieving optimal operating conditions in complex operating environments. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 Flowchart for implementing an adaptive tuning method for generating pulse-driven AC quantum voltage; DETAILED DESCRIPTION

[0025] The present invention will be further described below with reference to the accompanying drawings:

[0026] 1. Startup process

[0027] First, the system enters the startup phase of the parameter optimization process. At this point, key parameters to be adjusted must be selected from the system's device parameters. These parameters include the pulse amplitude and phase of the system's RF arbitrary waveform generator, the gain of the microwave amplifier, and the amplitude and phase of the bias compensation voltage. These parameters directly impact the generation of the pulsed AC quantum voltage. Selecting the appropriate parameter set is the first step in the optimization process, and its accuracy directly determines the efficiency and effectiveness of subsequent optimization steps.

[0028] A specific pulse train signal is generated using an RF arbitrary waveform generator. This pulse train is configured to adapt to the specified amplitude and frequency based on the synthesis requirements. By precisely controlling the pulse amplitude and phase parameters of the RF arbitrary waveform generator, a flexible and stable excitation source is provided for the pulse-driven AC quantum voltage synthesis system.

[0029] 2. Spectrum Analysis and THD Calculation

[0030] After selecting the parameters to be adjusted, the system-generated pulse train is input into the ADC sampler, where spectrum analysis is performed to obtain a signal spectrum. This spectrum reflects the distribution of the signal's frequency components, particularly the fundamental and harmonics. Next, the total harmonic distortion (THD) value is calculated. THD is a key indicator of signal purity, reflecting the strength of non-fundamental components in the signal. This step allows the effectiveness of the current parameter configuration to be evaluated, providing essential data support for subsequent optimization adjustments.

[0031] Specifically, the sampler's sampling rate is determined based on the fundamental frequency of the AC quantum voltage signal to be synthesized to ensure efficient signal acquisition. Setting the sampling rate is crucial; it must not only comply with the Nyquist sampling theorem to prevent signal aliasing, but also adapt to the specific frequency characteristics of the pulse sequence to capture complete signal information. This allows the sampler to acquire time-domain data of the measured signal with sufficient resolution and accuracy.

[0032] The collected time-domain data is converted into frequency-domain information through a Fourier transform, generating a spectrum of the measured signal. This spectrum details the distribution of the signal's frequency components, particularly the amplitude relationship between the fundamental wave and its harmonics. After obtaining the spectrum, the signal's total harmonic distortion (THD) is calculated. By calculating THD, the degree of harmonic distortion in the signal can be quantified, which is important for evaluating signal quality and system performance. A low THD value indicates a near-ideal signal with minimal harmonic distortion. A low THD value indicates a high level of higher-order harmonics, affecting overall system stability and measurement accuracy. This process provides critical spectrum data support for subsequent parameter optimization and system tuning.

[0033] 3. Automatic search algorithm based on the golden ratio

[0034] Based on the spectrum and THD results obtained in step 2, an automatic search algorithm based on the golden ratio is used to optimize the selected device parameters. The golden ratio algorithm is an effective global optimization method that can quickly find a near-optimal solution in the parameter space. In each iteration, the algorithm adjusts the parameter search range and updates its values ​​based on the current spectrum and THD feedback, gradually approaching the optimal parameter combination that minimizes THD and meets the required spectral characteristics. This process is repeated until the system performance indicators stabilize.

[0035] Specifically, when using an automatic search algorithm based on the golden ratio for parameter optimization, the optimization objective must be clearly defined: ensuring that the THD value remains stable at a minimum while maintaining the desired spectral characteristics. During initialization, the search range for the device parameters to be adjusted is defined, and the golden ratio algorithm is used to efficiently search within the parameter space. The algorithm continuously adjusts the parameters, obtaining a signal spectrum and calculating the THD value after each adjustment to evaluate the effectiveness of the current parameter settings. The algorithm iteratively narrows the search range to approach the optimal parameter settings. Each adjustment updates the search strategy based on the THD value and spectrum evaluation results to ensure that the THD value is minimized and the spectral characteristics meet the desired requirements. The optimization process concludes when the THD value stabilizes at its lowest point and the spectral characteristics meet the requirements. Finally, these optimal parameter configurations are recorded and applied to improve overall system performance and stability.

[0036] 4. Superimpose triangle waves and measure quantum operating margin

[0037] After completing the automated search and optimization described above, a triangular wave signal is superimposed on the bias compensation terminal of the pulse-driven Josephson chip. The system's response is observed by gradually increasing the amplitude of the triangular wave until harmonics appear in the signal spectrum and the THD value increases and becomes unstable. The quantum operating margin corresponding to the triangular wave amplitude at this point can be used to evaluate the effectiveness of the current parameter settings. This process allows the system's operating limits and stability to be determined under specific parameters.

[0038] Specifically, after parameter optimization, a triangular wave signal is superimposed on the bias compensation terminal of the pulse-driven Josephson chip. This process begins by gradually applying a triangular wave with increasing amplitude to observe its effect on the system response. As the amplitude of the triangular wave gradually increases, the system undergoes different operating states, ultimately leading to the appearance of harmonics in the signal spectrum—new frequency components in the spectrum. This typically indicates that the system is approaching its nonlinear or critical point.

[0039] During this process, the THD (total harmonic distortion) value increases significantly and becomes unstable, reflecting the increase in higher-order harmonic components in the system and further confirming the occurrence of harmonic phenomena. By accurately measuring and recording the amplitude of the triangle wave at this time, the quantum operating margin of the pulse-driven AC quantum voltage can be determined under the current parameter settings. This margin indicates the stability range of the system under operating conditions and the maximum excitation intensity it can withstand without causing signal distortion or performance degradation.

[0040] 5. Constructing the distribution curve of parameters and quantum working margin

[0041] Repeat steps 2 through 4 multiple times to obtain data on the quantum operating margin under different parameter configurations. This data is collated and analyzed to construct a distribution curve showing the relationship between the parameters to be adjusted and the quantum operating margin. This curve illustrates the impact of parameter changes on the quantum operating margin and helps identify the parameter combination that maximizes the quantum operating margin.

[0042] The process of establishing a distribution curve for the relationship between the parameters to be adjusted and the quantum operating margin of the pulse-driven AC quantum voltage involves repeatedly adjusting the device parameters, reacquiring the signal spectrum, and calculating the THD value. During each adjustment, a triangular wave signal is superimposed on the bias compensation terminal of the pulse-driven Josephson chip, and the amplitude of the triangular wave is gradually increased until a significant increase in harmonics and THD is observed. This process allows for a systematic evaluation of the quantum operating margin under different parameter conditions.

[0043] By iterating this process multiple times, a series of experimental data on the relationship between parameter configurations and quantum operating margins can be generated. This data is used to draw a distribution curve of the relationship between parameters and quantum operating margins, which details the impact of different parameter settings on the system operating margin. This relationship distribution curve not only reveals the specific impact of each parameter on system performance, but also helps identify the optimal parameter configuration, that is, the setting that maximizes the quantum operating margin among all tested parameters.

[0044] 6. Finalize the optimal parameter settings

[0045] Through multiple iterations and analysis of the relationship distribution curve, the optimal parameter settings that maximize the quantum operating margin were finally determined. This stage marks the end of the entire optimization process. The system parameters have been adjusted to the optimal configuration, which can provide the highest stability and optimal performance in practical applications, providing reliable support for the generation of pulse-driven AC quantum voltage systems.

Claims

1. An adaptive tuning method for generating a pulse-driven AC quantum voltage, characterized in that: The steps include: Step 1: Use a radio frequency arbitrary waveform generator to generate an arbitrary waveform signal pulse train with specific amplitude and frequency to drive the synthesis system; Step 2: Determine the sampling rate of the ADC sampler based on the fundamental frequency of the AC quantum voltage signal to be synthesized, obtain the spectrum of the measured signal, and calculate its total harmonic distortion (THD) value; Step 3: Using an automatic search algorithm based on the golden ratio, combined with the spectrum and THD results obtained in Step 2, gradually adjust the amplitude and phase of the arbitrary waveform generator, the gain of the amplifier, and the amplitude and phase of the compensation circuit until the THD value stabilizes and the spectrum characteristics meet the expected requirements. Step 4: After parameter optimization is completed, a triangular wave with increasing amplitude is gradually applied to the bias compensation terminal of the pulse-driven Josephson chip. As the amplitude of the triangular wave gradually increases, the system will experience different operating states, eventually causing harmonics to appear in the signal spectrum, that is, new frequency components appear in the spectrum; During this process, the THD value will increase significantly and tend to be unstable. By accurately measuring and recording the amplitude of the triangle wave at this time, the quantum operating margin of the pulse-driven AC quantum voltage can be determined under the current parameter settings. This margin represents the stability range of the system under working conditions and the maximum excitation intensity it can withstand. Step 5: After the system has completed preliminary optimization, repeat steps 2 to 4 multiple times to establish a distribution curve of the relationship between the parameters to be adjusted and the quantum operating margin of the pulse-driven AC quantum voltage. The specific operation includes repeatedly adjusting the device parameters, reacquiring the signal spectrum, and calculating the THD value. During each adjustment process, a triangular wave signal is superimposed on the bias compensation terminal of the pulse-driven Josephson chip, and the amplitude of the triangular wave is gradually increased until a significant increase in harmonics and THD is observed. Step three specifically includes: When using an automatic search algorithm based on the golden ratio for parameter optimization, the THD value is ensured to be stable at the minimum while the spectral characteristics meet the expected requirements. During initialization, the search range of the device parameters to be adjusted is defined, and the golden ratio algorithm is used to efficiently search in the parameter space, continuously adjusting the parameters. After each adjustment, the signal spectrum diagram and THD value are obtained. The algorithm iteratively narrows the search range to approach the optimal parameter setting. Each adjustment updates the search strategy based on the evaluation results of the THD value and spectrum diagram to ensure that the THD value is minimized and the spectral characteristics meet the expected requirements. When the THD value stabilizes at the lowest point and the spectral characteristics meet the requirements, the optimization process ends.

2. The adaptive tuning method for generating pulse-driven AC quantum voltage according to claim 1, characterized in that: The step 2 is specifically as follows: The sampling rate of the sampler is determined according to the fundamental frequency of the AC quantum voltage signal to be synthesized. The collected time domain data is converted into frequency domain information through Fourier transform to generate a spectrum diagram of the measured signal. After obtaining the spectrum diagram, the total harmonic distortion (THD) value of the signal is further calculated.

Images