A radio frequency system and implementation method of a quantum instrument control kit

Abstract

The present invention discloses a radio frequency system and implementation method of a quantum instrument control kit, which relates to the field of quantum measurement and control technology, including: a first signal processing circuit based on an RFSOC chip platform: used to generate a quantum signal and provide a clock signal, generate a stable local oscillator frequency signal after frequency synthesis of the signal in the signal source, and divide it into multiple amplified quantum signals after signal attenuation and amplification processing; a second signal processing circuit based on an RFSOC chip platform: used to perform attenuation matching processing on the high-frequency signal synthesized by the RFSOC chip platform, and mix the clock signal with the processed signal after filtering, amplify the mixed signal, and adjust the high dynamic range gain of the link by adjusting the dB value of the gain. The present invention can reduce the image frequency interference or intermediate frequency interference of the quantum signal under the premise of keeping the quantum signal frequency between 4GHZ and 8GHZ.

Description

Technical Field

[0001] The present invention relates to the field of quantum measurement and control technology, and in particular to a radio frequency system of a quantum instrument control kit and an implementation method thereof. Background Art

[0002] Quantum information and measurement and control are new information processing and measurement and control science and technology based on the coherent and entangled state resources of quantum mechanics. In the quantum computer industry, quantum chips are developing very rapidly. In order to achieve precise control of large-scale quantum bits, an integrated large-scale quantum chip measurement and control system is indispensable. At present, most quantum computer research and development teams use commercial instruments and equipment to build quantum computer control systems themselves, but because traditional scientific instruments are only responsible for a single signal output or acquisition task, this spliced ​​system is not only expensive and has poor compatibility, but also has shortcomings such as functional redundancy, difficulty in integration, and substandard indicators.

[0003] The main frequency band of quantum signals is between 4GHZ and 8GHZ. Traditional technology can only achieve output and measurement in this frequency band through secondary frequency conversion and other methods. In this type of architecture, high-speed DAC is mainly used to output low-frequency signals, which are converted into intermediate frequency signals through the first frequency conversion, and then the signals are moved to the high-frequency area through the second frequency conversion. Secondary frequency conversion can improve the suppression ability of image frequency signals, image frequency rejection ratio and signal sensitivity, but image frequency interference or intermediate frequency interference will still occur, which can be suppressed but not eliminated by secondary frequency conversion. Summary of the invention

[0004] The present invention provides a radio frequency system of a quantum instrument control kit and an implementation method thereof, which solves the problem in the prior art that when converting an intermediate frequency quantum signal into a high frequency quantum signal, interference suppression is prone to occur in the frequency conversion process and is difficult to eliminate.

[0005] The present invention is achieved through the following technical solutions:

[0006] A radio frequency system of a quantum instrument control kit includes an RFSOC chip platform, wherein the radio frequency system includes: a first signal processing circuit based on the RFSOC chip platform: used to generate a quantum signal and provide a clock signal, generate a stable local oscillator frequency signal after frequency synthesis of the signal in the signal source, and divide it into multiple amplified quantum signals after signal attenuation and amplification processing for subsequent signal processing and transmission; a second signal processing circuit based on the RFSOC chip platform: used to perform attenuation matching processing on the high-frequency signal synthesized by the RFSOC chip platform, and mix the clock signal of the first signal processing circuit with the processing signal after filtering and limit the mixing frequency range, and perform amplification gain processing on the mixed signal after filtering and adjust the high dynamic range gain of the link by adjusting the dB value of the gain. At present, the main frequency band of quantum signals is between 4GHZ and 8GHZ. The traditional output and measurement of this frequency band can only be achieved through secondary frequency conversion and other methods, that is, a high-speed DAC is usually used to output a low-frequency signal, which is then converted into an intermediate frequency signal through primary frequency conversion, and the signal is moved to the high-frequency area through secondary frequency conversion again. However, the signal-to-noise ratio of the mirror frequency signal generated in the process of generating the intermediate frequency signal by the secondary frequency conversion is usually difficult to meet the requirements of the quantum signal frequency conversion output to a specific frequency band; in the commonly used secondary frequency conversion process, the mirror frequency signal, as a parasitic signal of the receiver, will affect its background noise and amplitude-frequency response, which can easily lead to a decrease in the sensitivity of signal reception and an uneven frequency response. In response to this, the applicant provides a radio frequency system for a quantum instrument control kit, which directly synthesizes the quantum signal of the required carrier frequency through an RF front-end integrated chip, and then outputs the quantum signal of the required frequency after attenuation matching and mixing with a specific local oscillator signal, so as to achieve the purpose of converting the intermediate frequency quantum signal into a high-frequency quantum signal.

[0007] Among them, intermediate frequency interference refers to the interference caused by the intermediate frequency signal at the receiving end of the device being modulated by other signals. This type of interference is usually caused by noise signals or harmonic signals generated by radio equipment near the receiving device when it is working; and image frequency interference refers to useless signals that appear between the transmission and reception of device signals. Their frequencies are equal to or close to the intermediate frequency signals, so they are called "image frequencies". This type of interference is usually caused by stray radiation at the transmitting end of the signal device or mixing distortion at the receiving end. Both image frequency interference and intermediate frequency interference will affect the stability, sensitivity, signal-to-noise ratio and signal transmission quality of the communication system. The RFSOC chip platform is a radio frequency monolithic integrated chip platform. The second signal processing circuit is used to synthesize and generate a quantum signal with the required carrier frequency through the RFSOC chip platform, and the quantum signal is output to the state of the required parameters by initializing the operating frequency, power and other parameters of the RFSOC chip, and modulating, amplifying and processing the signal. The first signal processing circuit is mainly used to generate a local oscillator signal for modulating the high-frequency carrier signal; at the same time, it provides the clock signal required by the second signal processing circuit to the radio frequency system. In addition to providing the working clock cycle required by the circuit, the clock signal is also used to mix with the quantum signal processed in the second signal processing circuit to generate a new signal. The frequency of this new signal is numerically the sum of the frequency of the quantum signal and the frequency of the clock signal. This mixing method is called "sum frequency" because it involves the sum of two frequencies. It should be noted that in the process of realizing sum frequency, if the frequency of the quantum signal is higher than the frequency of the clock signal, then sum frequency cannot be realized. Therefore, in the specific implementation, it is necessary to set a suitable clock signal frequency under the premise that the quantum signal frequency band is between 4GHZ and 8GHZ to ensure that sum frequency can be achieved.

[0008] Furthermore, the first signal processing circuit includes: a signal source for providing an initial signal to be processed and converted; a clock buffer for generating a clock signal through the frequency of the initial signal and eliminating the delay and distortion of the clock signal; a phase-locked loop for modulating and demodulating the initial signal, outputting the signal through multiple channels and keeping the output signal in a fixed phase; a phase-locked attenuator for changing the phase of the phase-locked loop output signal to compensate for the phase error; a first-order gain amplifier module for gain amplifying the output effective signal; a power divider for power distribution of the gain-amplified output signal and outputting it through multiple channels; a second-order gain amplifier module for gain amplifying the branch signal after the power divider performs power distribution.

[0009] Furthermore, the second signal processing circuit includes: a balun module, which is used to attenuate and match the signal synthesized by the RFSOC chip platform; a first low-pass filter, which is used to filter the attenuated and matched signal; a fixed attenuator, which is used to match the level requirement of the attenuated input signal again; a mixer, which is used to mix the attenuated signal again with the clock signal of the local oscillator circuit; a second low-pass filter, which is used to filter the signal after mixing; a low-noise amplifier, which is used to convert the filtered quantum signal into a voltage signal and amplify the signal; an adjustable attenuator, which is used to adjust the intensity and level of the quantum signal; and a radio frequency switch, which is used to control the signal channel.

[0010] Furthermore, the phase-locked loop outputs signals through two output branches; the two output branches are respectively provided with a phase-locked attenuator, a first-order gain amplifier module and a power divider in sequence along the output end of the phase-locked loop; and the output end of each power divider is provided with two second-order gain amplifier modules.

[0011] Furthermore, the number of the adjustable attenuators is two, including a first adjustable attenuator and a second adjustable attenuator; the number of the low-noise amplifiers is two, including a first low-noise amplifier and a second low-noise amplifier; the first adjustable attenuator, the first low-noise amplifier, the second adjustable attenuator, and the second low-noise amplifier are connected in sequence along the output end of the second low-pass filter to perform two-stage amplification and adjustment on the output signal.

[0012] Furthermore, the resonant frequency range of the balun module is limited to 10 Hz-3 GHz, the insertion loss value thereof is limited to 1.5 dB, and the phase imbalance degree thereof is limited to 4 degrees.

[0013] A radio frequency implementation method for a quantum instrument control kit mainly includes: synthesizing a quantum signal and a local oscillator signal of a target carrier frequency; mixing the carrier signal with the local oscillator clock signal; and performing multi-stage gain adjustment on the signal within a high dynamic range.

[0014] Furthermore, when synthesizing quantum signals and local oscillator signals, the required quantum signals are directly synthesized on the RFSOC chip platform through the first Nyquist zone mode, and the local oscillator signal and clock signal of the required local oscillator frequency are generated through a phase-locked loop on the local oscillator circuit. The first Nyquist zone mode is a discrete signal system sampling theorem. If the Nyquist frequency of the discrete system is higher than the highest frequency or bandwidth of the sampled signal, aliasing can be avoided, so that the sampled signal can be reconstructed. For the generation and transmission of quantum signals, the use of the first Nyquist zone mode can improve the sampling rate and sampling accuracy, thereby improving the signal-to-noise ratio and transmission efficiency of quantum signals.

[0015] Furthermore, when mixing the carrier signal with the local oscillator clock signal, a mixer with a high noise coefficient is used; when adjusting the signal gain within a high dynamic range, the signal attenuation value in the channel must be less than -30dBm.

[0016] Furthermore, the method comprises the following main steps:

[0017] Step S1: The signal in the signal source is subjected to frequency synthesis to generate a stable local oscillator frequency signal, and after signal attenuation and amplification processing, it is divided into multiple amplified quantum signals, and the frequency of the output waveform is increased to above 6 GHz by undersampling, and a stable clock signal is generated by providing a clock frequency;

[0018] Step S2: After adjusting the required frequency range of the clock signal and the quantum signal, a carrier frequency of up to 3 GHz is synthesized through the RFSOC chip platform, and the quantum signal reaching high frequency is attenuated and matched through the balun module;

[0019] Step S3: Level matching is performed on the quantum signal after the preliminary attenuation matching process, and then the quantum signal is mixed with a clock with a local oscillator of 8 GHz or above, and the system frequency range is adjusted to 4 GHz ≤ f ≤ 8 GHz. After the bandpass filtering, the quantum signal is gain-amplified to reduce noise and improve signal quality;

[0020] Step S4: Two adjustable attenuators are set before and after the amplification to prevent amplification self-excitation and control the amplification gain. Then, a gain of 21dB is added at the output of the adjustable attenuator through amplification to increase the high dynamic range gain of the link. At this time, the channel gain is -30dBm. Finally, the channel is controlled by the RF switch.

[0021] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0022] 1. By mixing the quantum signal and the local oscillator clock signal in a limited frequency manner and performing matching work such as amplification and attenuation on the newly generated signal after mixing, the image frequency interference or intermediate frequency interference of the quantum signal can be significantly reduced while maintaining the quantum signal frequency between 4GHZ and 8GHZ;

[0023] 2. Power division of the local oscillator signal and the clock signal after gain amplification can effectively suppress the common mode signal in the circuit and reduce the line impedance, thereby improving the dynamic response characteristics of the entire RF system;

[0024] 3. Connecting a second low-pass filter at the output end of the mixer can filter out the high-frequency components of the new signal generated after mixing, thereby reducing noise and distortion, and further reducing the occurrence of image frequency interference or intermediate frequency interference. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The drawings described herein are used to provide a further understanding of the embodiments of the present invention, constitute a part of this application, and do not constitute a limitation of the embodiments of the present invention. In the drawings:

[0026] Figure 1 This is a functional block diagram of the first signal processing circuit of the present invention:

[0027] Figure 2 The schematic diagram of the second signal processing circuit of the present invention is

[0028] Figure 3 It is a flowchart of the method of the present invention. DETAILED DESCRIPTION

[0029] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with embodiments and drawings. The exemplary embodiments of the present invention and their description are only used to explain the present invention and are not intended to limit the present invention.

[0030] Example 1

[0031] like Figure 1-Figure 2 As shown, this embodiment includes a radio frequency system of a quantum instrument control kit, including an RFSOC chip platform, and the radio frequency system includes: a first signal processing circuit based on the RFSOC chip platform: used to generate a quantum signal and provide a clock signal, generate a stable local oscillator frequency signal through frequency synthesis of the signal in the signal source, and divide it into multiple amplified quantum signals after signal attenuation and amplification processing for subsequent signal processing and transmission; a second signal processing circuit based on the RFSOC chip platform: used to perform attenuation matching processing on the high-frequency signal synthesized by the RFSOC chip platform, and mix the clock signal of the first signal processing circuit with the processing signal after filtering and limit the mixing frequency range, amplify the mixed signal after filtering, and adjust the high dynamic range gain of the link by adjusting the dB value of the gain.

[0032] Through the RFSOC chip platform, the second signal processing circuit directly synthesizes and generates a quantum signal that can meet the required carrier frequency size, and initializes the target signal's operating frequency, power and other parameters, and outputs the quantum signal to the required parameter state through modulation amplification and signal processing. The first signal processing circuit is mainly used to generate a local oscillator signal for modulating the high-frequency carrier signal, and at the same time generates the clock signal required by the second signal processing circuit for the RF system. In addition to providing the working clock cycle required by the circuit, the clock signal is also used to mix with the quantum signal processed in the second signal processing circuit to generate a new signal. The frequency of this new signal is numerically the sum of the frequency of the quantum signal and the frequency of the clock signal. This mixing method is called "sum frequency" because it involves the sum of two frequencies.

[0033] Among them, the first signal processing circuit includes: a signal source, which is used to provide an initial signal to be processed and converted; a clock buffer, which is used to generate a clock signal through the frequency of the initial signal and eliminate the delay and distortion of the clock signal; a phase-locked loop, which is used to modulate and demodulate the initial signal, output the signal through multiple channels and keep the output signal in a fixed phase; a phase-locked attenuator, which is used to change the phase of the output signal of the phase-locked loop to compensate for the phase error; a first-order gain amplifier module, which is used to gain amplify the output effective signal; a power divider, which is used to power distribute the output signal after gain amplification and output it through multiple channels; a second-order gain amplifier module, which is used to gain amplify the branch signal after power distribution by the power divider; the phase-locked loop outputs the signal through two output branches; the two output branches are respectively provided with a phase-locked attenuator, a first-order gain amplifier module and a power divider in sequence along the output end of the phase-locked loop; the output end of each power divider is provided with two second-order gain amplifier modules.

[0034] Furthermore, the second signal processing circuit includes: a balun module, which is used to attenuate and match the signal synthesized by the RFSOC chip platform, and its resonant frequency range is limited to 10Hz-3GHz, its insertion loss value is limited to 1.5dB, and its phase imbalance is limited to 4 degrees; a first low-pass filter, which is used to filter the attenuated matched signal; a fixed attenuator, which is used to match the level requirement of the attenuated input signal again; a mixer, which is used to mix the attenuated signal again with the clock signal of the local oscillator circuit; a second low-pass filter, which is used to filter the signal after mixing; a low-noise amplifier, which is used to filter the filtered signal. The processed quantum signal is converted into a voltage signal and the signal is amplified; an adjustable attenuator is used to adjust the strength and level of the quantum signal; a radio frequency switch is used to control the signal channel; an antenna module is used to transmit the signal outward; wherein the number of the adjustable attenuators is two, including a first adjustable attenuator and a second adjustable attenuator; the number of the low-noise amplifiers is two, including a first low-noise amplifier and a second low-noise amplifier; the first adjustable attenuator, the first low-noise amplifier, the second adjustable attenuator, and the second low-noise amplifier are connected in sequence along the output end of the second low-pass filter to perform two-stage amplification and adjustment on the output signal.

[0035] In the process of achieving sum frequency, if the frequency of the quantum signal is higher than the frequency of the clock signal, then sum frequency cannot be achieved. Therefore, in the specific implementation, it is necessary to set a suitable clock signal frequency under the premise that the quantum signal frequency band is between 4GHZ and 8GHZ to ensure that sum frequency can be achieved. When working, in the specific implementation of the RFSOC chip platform, the first signal processing circuit is first used to generate the local oscillator signal and the clock signal, and the voltage-controlled oscillator and the frequency divider built into the phase-locked loop are used to generate the local oscillator signal and the clock signal respectively. In the specific application, in order to avoid information loss during the undersampling process, the set frequency of the local oscillator signal and the clock signal can be more than twice higher than the carrier frequency of the target quantum signal. After that, the phase-locked loop output end is connected to the phase-locked attenuator, which is used to change the phase of the phase-locked loop output signal to compensate for the phase error, and is also used to separate the clock signal and the local oscillator signal so that they will not be affected at the same time, thereby improving the anti-interference effect; at the same time, it can improve the nonlinear distortion, and attenuate the output local oscillator signal and the clock signal to about half of their amplitude to reduce the nonlinear distortion of the system, thereby improving the system stability and reducing the image frequency interference of the signal. The first-order gain amplification module, the power divider, and the second-order gain amplification module are connected to the output end of the phase-locked loop in sequence along the two output branches of the phase-locked loop, and are used to divide the local oscillator signal and the clock signal after gain amplification, which is used to effectively suppress the common mode signal and reduce the line impedance, thereby improving the dynamic response characteristics of the system. After that, the local oscillator signal and the clock signal are gain-amplified again, so that the amplification factor is further increased, thereby obtaining better voltage tracking characteristics.

[0036] During the operation of the second signal processing circuit, the RFSOC chip platform is first used to directly synthesize a quantum signal with a carrier frequency of more than 3GHz in the first Nyquist zone mode. Since the signal is collected using the undersampling method, the frequency of the local oscillator signal and the clock signal in the local oscillator circuit must reach more than 6GHz. The balun module performs attenuation matching and primary signal processing on the synthesized quantum signal. The balun module first collects the quantum signal synthesized on the RFSOC chip platform, and performs preliminary digital filtering and digital gain to optimize the signal quality and signal-to-noise ratio. The signal output end of the balun module is connected to the first low-pass filter, which is used to filter out high-frequency noise signals, thereby improving the quality and signal-to-noise ratio of the output signal. Specifically, the low-pass filter only allows signals below the cutoff frequency to pass, and prevents signals above the cutoff frequency from passing. Therefore, connecting the low-pass filter to the output end of the balun module can effectively suppress high-frequency noise signals, thereby reducing the noise level of the signal, improving the quality and signal-to-noise ratio of the signal, and significantly reducing the occurrence of intermediate frequency interference; and with the help of the low-pass filter, it is used to eliminate the influence of the image frequency signal, thereby achieving the effect of eliminating image frequency interference or intermediate frequency interference. When low-pass filtering is performed, a fixed attenuator is connected. On the one hand, it is used to reduce the amplitude of the signal so as to better control the power level and stability of the signal. On the other hand, since the signal amplitude output by the balun module may be relatively large, if it is not attenuated, it may cause the signal to have overvoltage, distortion, harmonics and other undesirable conditions. By connecting a fixed attenuator at the output end, the amplitude of the signal can be reduced by a certain proportion, thereby ensuring the stability and reliability of the signal. At the same time, the attenuator can also protect subsequent electronic devices from excessive signal impact and interference. The role and effect of using the first Nyquist zone mode to generate quantum signals is mainly to improve the signal-to-noise ratio of quantum signals and reduce aliasing. The first Nyquist zone mode is a discrete signal system sampling theorem. If the Nyquist frequency of the discrete system is higher than the highest frequency or bandwidth of the sampled signal, aliasing can be avoided, so that the sampled signal can be reconstructed. For the generation and transmission of quantum signals, the first Nyquist zone mode can improve the sampling rate and sampling accuracy, thereby improving the signal-to-noise ratio and transmission efficiency of quantum signals. In addition, the first Nyquist zone mode can also reduce the distortion and distortion of quantum signals, thereby reducing the bit error rate and improving the reliability and security of the communication system. Therefore, in practical applications, the first Nyquist zone mode is usually used to generate quantum signals to improve the performance and reliability of quantum communication systems, thereby providing auxiliary effects in eliminating mirror frequency interference or intermediate frequency interference.

[0037] When a mixer is used to mix a quantum signal with a clock signal whose local oscillator is above 8GHz, the quantum signal and the clock signal are input into the mixer. In the mixer, the quantum signal and the clock signal interact with each other to generate a series of frequency components. Among them, the frequency difference is the difference between the clock signal frequency and the quantum signal frequency, which is called the "mixing frequency". The mixed signal contains a series of frequency components, and unnecessary frequency components need to be removed by a filter. At the same time, the cutoff frequency of the filter should be the same as the mixing frequency. Therefore, a second low-pass filter is connected to the output end of the mixer to filter out the high-frequency components generated by the mixing of the new signal generated after mixing, thereby reducing noise and distortion to meet the system requirements of the frequency range of 4GHz≤f≤8GHz. The high-frequency components generated by the mixer may interfere with the transmission and reception of quantum signals. If filtering is not performed, these high-frequency components may have adverse effects on the quantum communication system, such as causing signal distortion and reducing the signal-to-noise ratio of the system. In specific implementation, when filtering, it is necessary to select a filter with a suitable cutoff frequency and steepness to avoid affecting the signal components that need to be retained. The first adjustable attenuator, the first low noise amplifier, the second adjustable attenuator, the second low noise amplifier, the radio frequency switch and the antenna module are sequentially connected and arranged at the output end of the second low pass filter. The first and second adjustable attenuators are used to provide control and compensation of the signal level to obtain a better mixing effect and a higher signal-to-noise ratio. The level of the mixer output signal may be affected by various factors, such as the nonlinearity of the mixer itself, the power fluctuation of the signal source, the loss of the transmission path, etc. In order to obtain a better mixing effect and a higher signal-to-noise ratio, it is necessary to adjust the level of the mixer output signal to a suitable level. The adjustable attenuator can provide accurate control of the signal level so that the level of the output signal can be adjusted and compensated within a larger range. If the level of the mixer output signal is too large, it may cause excessive impact and interference to subsequent electronic equipment, resulting in equipment damage or bit errors. By connecting the adjustable attenuator at the output end of the mixer, accurate control of the signal level can be achieved to avoid the influence of excessive signal levels on subsequent electronic equipment. In the specific implementation, it is necessary to select a suitable attenuation amount and attenuation range to avoid affecting the signal components that need to be retained. For example, in this solution, the attenuation value of the first and second adjustable attenuators must be less than -30dBm, that is, the attenuation value can be set to 31.75dBm. The role and effect of setting the adjustable attenuator and the low-noise amplifier at intervals is mainly to achieve precise control and optimization of the signal level, thereby improving the stability and reliability of the system. The adjustable attenuator can provide precise control and compensation of the signal level, while the low-noise amplifier can amplify the signal level and improve the signal-to-noise ratio of the system. By setting the adjustable attenuator and the low-noise amplifier at intervals, precise control and optimization of the signal level can be achieved, thereby achieving the effect of eliminating image frequency interference or intermediate frequency interference.As a feasible implementation, the low noise amplifier may use a chip amplifier, which has the advantages and benefits of low noise figure, higher gain, smaller size and lower power consumption.

[0038] It should be noted that the frequency of the local oscillator signal is set by means of a phase detector and a corresponding control circuit in a phase-locked loop. Specifically, a phase detector is used to compare the phases of the input signal and the output signal to generate a voltage control signal, which generates a control voltage after passing through a low-pass filter to control the frequency of the voltage-controlled oscillator. The frequency of the local oscillator signal is adjusted in this process until its phase is synchronized with the phase of the input signal. In specific applications, the phase detector is usually composed of two differential amplifiers, which receive the input signal and the output signal respectively and compare the two signals. If the phases of the input signal and the output signal are the same, the phase detector outputs a voltage to increase the frequency of the voltage-controlled oscillator; if the phases of the input signal and the output signal are different, the phase detector outputs another voltage to reduce the frequency of the voltage-controlled oscillator. This process is called "locking". When the phases of the input signal and the output signal are synchronized, the phase detector is in a "locked" state.

[0039] In specific applications, as a feasible implementation method, a mixer with a high noise coefficient can be selected. In the process of mixing quantum signals with clock signals, a mixer with a high noise coefficient can generate more noise and interference signals, thereby reducing the signal-to-noise ratio of the mixed signal. Specifically, the noise coefficient of the mixer indicates the size of the noise introduced by the mixer. The higher the noise coefficient, the greater the noise introduced by the mixer. When mixing a quantum signal with a clock signal, if the noise coefficient of the mixer is high, more noise and interference signals will be generated, resulting in a decrease in the signal-to-noise ratio of the mixed signal. In addition, the noise of the mixer will also affect the phase and amplitude of the mixed signal, thereby affecting the quality of the mixed signal. Therefore, in practical applications, it is necessary to select a mixer with a lower noise coefficient to obtain a better mixing effect and a higher signal-to-noise ratio.

[0040] Example 2

[0041] like Figure 2As shown, this embodiment includes a radio frequency implementation method for a quantum instrument control kit, the main contents of which include: synthesizing a quantum signal and a local oscillator signal of a target carrier frequency; mixing the carrier signal with the local oscillator clock signal; and performing multi-order gain adjustment on the signal within a high dynamic range. When synthesizing the quantum signal and the local oscillator signal, the required quantum signal is directly synthesized on the RFSOC chip platform through the first Nyquist zone mode, and a local oscillator signal and a clock signal of the required local oscillator frequency are generated through a phase-locked loop on the local oscillator circuit. When mixing the carrier signal with the local oscillator clock signal, a mixer with a high noise coefficient is used; when adjusting the signal gain within a high dynamic range, the signal attenuation value in the channel must be less than -30dBm.

[0042] The method includes the following main steps:

[0043] Step S1: The signal in the signal source is subjected to frequency synthesis to generate a stable local oscillator frequency signal, and after signal attenuation and amplification processing, it is divided into multiple amplified quantum signals, and the frequency of the output waveform is increased to above 6 GHz by undersampling, and a stable clock signal is generated by providing a clock frequency;

[0044] Step S2: After adjusting the required frequency range of the clock signal and the quantum signal, a carrier frequency of up to 3 GHz is synthesized through the RFSOC chip platform, and the quantum signal reaching high frequency is attenuated and matched through the balun module;

[0045] Step S3: Level matching is performed on the quantum signal after the preliminary attenuation matching process, and then the quantum signal is mixed with a clock with a local oscillator of 8 GHz or above, and the system frequency range is adjusted to 4 GHz ≤ f ≤ 8 GHz. After the bandpass filtering, the quantum signal is gain-amplified to reduce noise and improve signal quality;

[0046] Step S4: Two adjustable attenuators are set before and after the amplification to prevent amplification self-excitation and control the amplification gain. Then, a gain of 21dB is added at the output of the adjustable attenuator through amplification to increase the high dynamic range gain of the link. At this time, the channel gain is -30dBm. Finally, the channel is controlled by the RF switch.

[0047] The specific implementation methods described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific implementation method of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A radio frequency system of a quantum instrument control kit, including an RFSOC chip platform, characterized in that: The radio frequency system comprises: The first signal processing circuit based on the RFSOC chip platform is used to generate quantum signals and provide clock signals. The signal in the signal source is synthesized to generate a stable local oscillator frequency signal, and after signal attenuation and amplification processing, it is divided into multiple amplified quantum signals for subsequent signal processing and transmission. The second signal processing circuit based on the RFSOC chip platform is used to perform attenuation matching processing on the high-frequency signal synthesized by the RFSOC chip platform, and mix the clock signal of the first signal processing circuit with the processing signal after filtering and limit the mixing frequency range, amplify the gain of the mixed signal after filtering, and adjust the high dynamic range gain of the link by adjusting the dB value of the gain.

2. The radio frequency system of a quantum instrument control kit according to claim 1, characterized in that: The first signal processing circuit comprises: A signal source, used to provide an initial signal to be converted; A clock buffer for generating a clock signal by using the frequency of an initial signal and eliminating delay and distortion of the clock signal; Phase-locked loop, used to modulate and demodulate the initial signal, output the signal through multiple channels and keep the output signal in a fixed phase; A phase-locked attenuator is used to change the phase of the phase-locked loop output signal to compensate for the phase error; The first-order gain amplifier module is used to amplify the output effective signal; A power divider is used to distribute the power of the output signal after gain amplification and output it through multiple channels; The second-order gain amplifier module is used to amplify the gain of the branch signal after the power divider performs power distribution.

3. The radio frequency system of a quantum instrument control kit according to claim 1, characterized in that: The second signal processing circuit comprises: The balun module is used to attenuate and match the signal synthesized by the RFSOC chip platform; A first low-pass filter, used for filtering the attenuation-matched signal; Fixed attenuator, used to match the level requirement of the attenuated input signal again; A mixer, used for mixing the attenuated signal again with a clock signal of a local oscillator circuit; A second low-pass filter, used for filtering the signal after the mixing process; A low noise amplifier, used to convert the filtered quantum signal into a voltage signal and amplify the signal; An adjustable attenuator, used to adjust the intensity and level of the quantum signal; RF switch, used to control the signal channel.

4. According to the radio frequency system of a quantum instrument control kit according to claim 2, the phase-locked loop outputs signals through two output branches; the two output branches are respectively provided with a phase-locked attenuator, a first-order gain amplifier module and a power divider in sequence along the output end of the phase-locked loop; and the output end of each power divider is provided with two second-order gain amplifier modules.

5. According to the radio frequency system of a quantum instrument control kit according to claim 3, the number of the adjustable attenuators is two, including a first adjustable attenuator and a second adjustable attenuator; the number of the low noise amplifiers is two, including a first low noise amplifier and a second low noise amplifier; the first adjustable attenuator, the first low noise amplifier, the second adjustable attenuator, and the second low noise amplifier are connected in sequence along the output end of the second low-pass filter to perform two-stage amplification and adjustment on the output signal.

6. The radio frequency system of a quantum instrument control kit according to claim 3, characterized in that: The resonant frequency range of the balun module is limited to 10 Hz-3 GHz, the insertion loss value is limited to 1.5 dB, and the phase imbalance is limited to 4 degrees.

7. A radio frequency implementation method for a quantum instrument control kit, characterized in that: The main contents of this method include: Synthesize the quantum signal and local oscillator signal of the target carrier frequency; Mixing the carrier signal with the local oscillator clock signal; The signal is adjusted by multiple steps of gain within a high dynamic range.

8. The radio frequency implementation method of a quantum instrument control kit according to claim 7, characterized in that: When synthesizing quantum signals and local oscillator signals, the required quantum signals are directly synthesized on the RFSOC chip platform through the first Nyquist zone mode, and the local oscillator signal and clock signal of the required local oscillator frequency are generated through a phase-locked loop on the local oscillator circuit.

9. The radio frequency implementation method of a quantum instrument control kit according to claim 7, characterized in that: When mixing the carrier signal with the local oscillator clock signal, a mixer with a high noise coefficient is used; when adjusting the signal gain within a high dynamic range, the signal attenuation value in the channel must be less than -30dBm.

10. The radio frequency implementation method of a quantum instrument control kit according to any one of claims 7 to 9, characterized in that: The method includes the following main steps: Step S1: The signal in the signal source is subjected to frequency synthesis to generate a stable local oscillator frequency signal, and after signal attenuation and amplification processing, it is divided into multiple amplified quantum signals, and the frequency of the output waveform is increased to above 6 GHz by undersampling, and a stable clock signal is generated by providing a clock frequency; Step S2: After adjusting the required frequency range of the clock signal and the quantum signal, a carrier frequency of up to 3 GHz is synthesized through the RFSOC chip platform, and the quantum signal reaching high frequency is attenuated and matched through the balun module; Step S3: Level matching is performed on the quantum signal after the preliminary attenuation matching process, and then the quantum signal is mixed with a clock with a local oscillator of 8 GHz or above, and the system frequency range is adjusted to 4 GHz ≤ f ≤ 8 GHz. After the bandpass filtering, the quantum signal is gain-amplified to reduce noise and improve signal quality; Step S4: Two adjustable attenuators are set before and after the amplification to prevent amplification self-excitation and control the amplification gain. Then, a gain of 21dB is added at the output of the adjustable attenuator through amplification to increase the high dynamic range gain of the link. At this time, the channel gain is -30dBm. Finally, the channel is controlled by the RF switch.

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