Clock regulation and control method, clock circuit and electronic equipment

Abstract

The embodiment of the invention provides a clock regulation and control method, a clock circuit and electronic equipment, and the clock regulation and control method can comprise the steps: taking an M1 subharmonic signal as a local oscillator signal, and carrying out the component processing of a detection signal, and obtaining a first Q signal; wherein the M1 subharmonic signal and the detection signal are output by a clock circuit; taking the M2 subharmonic signal as a local oscillator signal, and performing component processing on the detection signal to obtain a second Q signal; wherein the M2 and the M1 are both positive integers, and the M2 and the M1 are not equal; processing the first Q signal and the second Q signal to obtain a control signal; wherein the control signal is used for regulating and controlling the clock circuit to output a clock signal.

Description

Technical Field

[0001] The present application relates to the field of clock control technology, and in particular to a clock control method, a clock circuit, and an electronic device. Background Art

[0002] A high-precision clock is a device that can provide accurate and stable time measurement. It is widely used in scientific research, navigation systems such as the Global Positioning System (GPS), communication systems, financial transactions, scientific experiments, and other fields that require high time accuracy.

[0003] Currently, the clock is implemented using a digital processor and proportional-integral-differential control. This control method has a low modulation frequency, and this control mode clock control method cannot meet the control requirements of more different clocks. Summary of the Invention

[0004] The purpose of this application is to provide a clock control method, a clock circuit and an electronic device that can adapt to more clock control requirements and improve the stability of clock control.

[0005] In a first aspect, an embodiment of the present application provides a clock control method, comprising: using an M1 subharmonic signal as a local oscillator signal, performing component processing on a detection signal, and obtaining a first Q signal; wherein the M1 subharmonic signal and the detection signal are output by a microwave output module of a clock circuit; using an M2 subharmonic signal as a local oscillator signal, performing component processing on the detection signal, and obtaining a second Q signal; wherein M2 and M1 are both positive integers, and M2 is not equal to M1, and the M2 subharmonic signal is output by a clock circuit; processing the first Q signal and the second Q signal to obtain a control signal; wherein the control signal is used to control the clock circuit to output a clock signal.

[0006] In the above embodiment, by performing mixed processing on multiple groups of Q signals, a harmonic signal greater than the first harmonic can be used as the basis for determining the control signal, thereby reducing the impact of spectral baseline drift caused by clock usage on the calculation in a multi-harmonic manner, thereby improving the long-term stability of the clock circuit. This method, through the combination of two groups of Q signals, can better utilize the effects of harmonic signals of different orders on clock control. For example, high-order harmonic signals can suppress spectral baseline drift, and low-order harmonic signals can have a higher signal-to-noise ratio, adapting to more different clocks and clock control requirements in different scenarios.

[0007] In an optional embodiment, the processing of the first Q signal and the second Q signal to obtain a control signal includes: performing gain processing on the first Q signal using a first gain coefficient to obtain a first gain signal; performing gain processing on the second Q signal using a second gain coefficient to obtain a second gain signal; and obtaining a control signal based on the first gain signal and the second gain signal.

[0008] In the above embodiment, the first Q signal and the second Q signal can be processed respectively based on the first gain coefficient and the second gain coefficient to achieve separate gains for Q signals of different orders, which can better balance the influence of the two Q signals of different orders on the control signal to achieve control signal adjustment, thereby improving the stability of the clock circuit.

[0009] In an optional embodiment, performing gain processing on the first Q signal using a first gain coefficient to obtain a first gain signal includes: performing integration processing on the first Q signal using the first gain coefficient to obtain the first gain signal.

[0010] In an optional implementation, performing gain processing on the second Q signal using a second gain coefficient to obtain a second gain signal includes: performing amplification processing on the second Q signal using the second gain coefficient to obtain the second gain signal.

[0011] In an optional embodiment, obtaining a control signal based on the first gain signal and the second gain signal includes: summing the first gain signal, the second gain signal and a bias signal to obtain the control signal; wherein the bias signal is provided by the power supply of the clock circuit through a resistor divider, or provided by a voltage reference chip connected to the clock circuit.

[0012] In an optional embodiment, the control signal is determined by the following formula:

[0013] C i -C i-1 =-k P (E i，M1 -E i-1，M1 )-k I E i，M2 ;

[0014] Among them, C i represents the control signal corresponding to the i-th detection signal; C i-1 represents the control signal corresponding to the i-1th detection signal; k P represents the first gain coefficient; k I Represents the second gain coefficient; E i，M1 represents the first Q signal corresponding to the i-th detection signal; Ei-1，M1 represents the first Q signal corresponding to the i-1th detection signal; E i，M2 Represents the second Q signal corresponding to the i-th detection signal.

[0015] In an optional embodiment, the first gain coefficient is greater than zero, and the second gain coefficient is smaller than the first gain coefficient; or, the second gain coefficient is greater than zero, and the first gain coefficient is smaller than the second gain coefficient.

[0016] In the above embodiment, by setting the relative sizes of the first gain coefficient and the second gain coefficient, the influence of the first Q signal and the second Q signal on the clock control can be adaptively adjusted, thereby achieving more flexible clock control to adapt to the clock regulation requirements in different states and improve the flexibility and stability of clock control.

[0017] In an optional embodiment, the method of using the M1 harmonic signal as the local oscillator signal and performing component processing on the detection signal to obtain a first Q signal includes: using the M1 harmonic signal as the local oscillator signal and performing mixing processing on the detection signal to obtain a first initial Q signal; and filtering the first initial Q signal to filter out the AC component in the first initial Q signal to obtain a first Q signal.

[0018] In an optional implementation, the first initial Q signal is determined by the following formula:

[0019] Q i，M1 =-P i ×sin(2πM1f m t+φ dem，M1 );

[0020] Among them, f m Indicates the modulation frequency used to determine the M1 harmonic signal; φ dem，M1 Indicates the demodulation phase of the sub-M1 harmonic; P i represents the i-th detection signal in the detection signal sequence; Q i，M1 represents the first initial Q signal; t represents the frequency modulation start-up time.

[0021] In an optional embodiment, the method further includes: calculating the amplitude and phase of a signal curve at each scanning frequency point based on the M1 subharmonic signal and the detection signal; wherein the scanning frequency point is determined by configuring a scanning frequency condition during the process of outputting a microwave signal from the clock circuit; from the amplitudes of the signal curve calculated at each scanning frequency point, selecting a target amplitude of the signal curve that meets a set condition, and using the phase at the scanning frequency point where the target amplitude exists as the optimal demodulation phase;

[0022] The method of using the M1 subharmonic signal as the local oscillator signal and mixing the detection signal to obtain the first initial Q signal includes: using the M1 subharmonic signal as the local oscillator signal and mixing the detection signal to obtain the first initial Q signal according to the optimal demodulation phase.

[0023] In an optional embodiment, the target amplitude of the signal curve that satisfies a set condition is selected from the amplitudes of the signal curve calculated at each scanning frequency point, including: determining a set of target scanning frequency points that are greater than the molecular resonance frequency from the plurality of scanning frequency points; wherein the molecular resonance frequency is determined by a spectrum curve formed by a detection signal output by the clock circuit; and determining, based on the amplitudes of the signal curves of each target scanning frequency point in the set of target scanning frequency points, a signal curve with the largest amplitude as the target amplitude.

[0024] In an optional embodiment, the amplitude and phase of the signal curve are calculated using the following formula:

[0025]

[0026] φ M1 (ν0+ν sweep，i )=arg(I M1 (ν0+ν sweep，i )+iQ M1 (ν0+ν sweep，i ));

[0027] Among them, ν sweep，i Indicates the i-th scanning frequency point; v0 indicates the center frequency value; I M1 (v0+v sweep，i ) indicates that at the scanning frequency point v sweep，i I signal under; Q M1 (ν0+ν sweep，i ) represents the scanning frequency point ν sweep，i Q signal under; A M1 (ν0+ν sweep，i ) represents the scanning frequency point ν sweep，i The amplitude of the signal curve below; φ M1 (v0+v sweep，i ) at the scanning frequency point v sweep，i The next phase.

[0028] In an optional embodiment, the method of using the M1 subharmonic signal as the local oscillator signal according to the optimal demodulation phase and mixing the detection signal to obtain the first initial Q signal is implemented by the following formula:

[0029]

[0030] Among them, Q i，M1 represents the first initial Q signal; P i represents the i-th detection signal in the detection signal sequence; f m represents the modulation frequency; t represents the modulation duration; Indicates the optimal demodulation phase of the M1 harmonic.

[0031] In an optional embodiment, the method of using the M2 harmonic signal as the local oscillator signal and performing component processing on the detection signal to obtain a second Q signal includes: using the M2 harmonic signal as the local oscillator signal and performing mixing processing on the detection signal to obtain a second initial Q signal; and filtering the second initial Q signal to filter out the AC component in the second initial Q signal to obtain a second Q signal.

[0032] In an optional implementation, the second initial Q signal is determined by the following formula:

[0033] Q i，M2 =-P i ×sin(2πM2f m t+φ dem，M2 );

[0034] Among them, f m Indicates the modulation frequency used to determine the M2 harmonic signal; φ dem，M2 Indicates the demodulation phase of the M2 harmonic; P i represents the i-th detection signal in the detection signal sequence; Q i，M2 represents the second initial Q signal; t represents the frequency modulation start-up time.

[0035] In an optional embodiment, at each scanning frequency point, the amplitude and phase of the signal curve are calculated based on the M2 subharmonic signal and the detection signal; wherein the scanning frequency point is determined by configuring a scanning frequency condition during the process of outputting a microwave signal from the clock circuit; from the amplitudes of the signal curve calculated at each scanning frequency point, a target amplitude of the signal curve that meets the set condition is selected, and the phase at the scanning frequency point where the target amplitude exists is used as the optimal demodulation phase;

[0036] The method of using the M2 harmonic signal as the local oscillator signal and mixing the detection signal to obtain the second initial Q signal includes: using the M2 harmonic signal as the local oscillator signal and mixing the detection signal according to the optimal demodulation phase to obtain the second initial Q signal.

[0037] In an optional embodiment, the target amplitude of the signal curve that satisfies a set condition is selected from the amplitudes of the signal curve calculated at each scanning frequency point, including: determining a set of target scanning frequency points that are greater than the molecular resonance frequency from the plurality of scanning frequency points; wherein the molecular resonance frequency is determined by a spectrum curve formed by a detection signal output by the clock circuit; and determining, based on the amplitudes of the signal curves of each target scanning frequency point in the set of target scanning frequency points, a signal curve with the largest amplitude as the target amplitude.

[0038] In an optional embodiment, the amplitude and phase of the signal curve are calculated using the following formula:

[0039]

[0040] φ M2 (v0+v sweep，i )=arg(I M2 (v0+v sweep，i )+iQ M2 (v0+v sweep，i ));

[0041] Among them, v sweep，i Indicates the i-th scanning frequency point; v0 indicates the center frequency value; I M2 (v0+v sweep，i ) indicates that at the scanning frequency point v sweep，i I signal under; Q M2 (v0+v sweep，i ) indicates that at the scanning frequency point v sweep，i Q signal under; A M2 (v0+v sweep，i ) indicates that at the scanning frequency point v sweep，i The amplitude of the signal curve below; φ M2 (v0+v sweep，i ) at the scanning frequency point v sweep，i The next phase.

[0042] In an optional embodiment, the method of using the M2 harmonic signal as the local oscillator signal according to the optimal demodulation phase and mixing the detection signal to obtain the second initial Q signal is implemented by the following formula:

[0043]

[0044] Among them, Q i，M2 represents the second initial Q signal; P i represents the i-th detection signal in the detection signal sequence; f m represents the modulation frequency; t represents the modulation duration; Indicates the optimal demodulation phase of the M2 harmonic.

[0045] In an optional embodiment, the method further includes: determining multiple groups of derivative relationships based on multiple harmonic signals and the detection signal; wherein each harmonic signal has a corresponding order of the harmonic signal, and each group of derivative relationships has a corresponding order; for each group of derivative relationships, calculating its frequency discrimination efficiency estimate value based on the derivative relationship to obtain the frequency discrimination efficiency estimate value of each group of derivative relationships; and determining the values ​​of M1 and M2 based on the frequency discrimination efficiency estimate value of each group of derivative relationships.

[0046] In the above embodiment, by determining the estimated value of the demodulation efficiency, the influence of harmonic signals of different orders on the control effect can be better determined. The values ​​of M1 and M2 determined based on the estimated value of the demodulation efficiency can achieve modulation data that is more suitable for the molecular clock, thereby making the clock adjustment more accurate and stable.

[0047] In an optional embodiment, the method further includes: constructing a spectrum curve based on the detection signal; determining a spectrum line baseline based on the spectrum curve; determining bias information based on the spectrum line baseline and the molecular resonance frequency; determining the values ​​of M1 and M2 based on the estimated values ​​of the discrimination efficiency of each group of derivative relationships, including: determining the values ​​of M1 and M2 based on the bias information and the estimated values ​​of the discrimination efficiency of each group of derivative relationships.

[0048] In the above embodiment, by determining the estimated value of the discrimination efficiency and the bias information, the influence of harmonic signals of different orders on the control effect can be better determined. The values ​​of M1 and M2 determined based on the estimated value of the discrimination efficiency and the bias information can achieve modulation data that is more suitable for the molecular clock, thereby making the clock adjustment more accurate and stable.

[0049] In an optional embodiment, constructing a spectral curve based on the detection signal includes: for each scanning frequency point, calculating the mean of each detection signal of the detection signal sequence obtained at the scanning frequency point as the spectral signal value; performing curve fitting on the spectral signal values ​​calculated at each scanning frequency point to obtain a spectral curve with the scanning frequency point as the independent variable.

[0050] In an optional implementation, the bias information is determined by the following formula:

[0051]

[0052] Among them, y b， N represents bias information; E b，N Indicates the error bias caused by the spectral baseline; v C represents the molecular resonance frequency; m represents the modulation amplitude; kd，N Indicates the estimated value of the frequency discrimination efficiency corresponding to the N-th order derivative relationship.

[0053] In an optional embodiment, multiple sets of derivative relationships are determined based on multiple harmonic signals and the detection signal, including: for each scanning frequency point, calculating the mean of each Q signal of the Q signal sequence obtained at the scanning frequency point as the derivative error signal value; and performing curve fitting on the derivative error signal value calculated at each scanning frequency point to obtain a derivative relationship with the scanning frequency point as the independent variable.

[0054] In an optional embodiment, calculating the estimated value of the discrimination efficiency based on the derivative relationship includes: calculating a derivative value of the derivative relationship at a point where the molecular resonance frequency is located, and using the derivative value as the estimated value of the discrimination efficiency.

[0055] In an optional embodiment, the method further comprises: determining at least two sets of derivative relationships based on the multiple harmonic signals and the detection signal; wherein the orders of the at least two sets of derivative relationships are even numbers;

[0056] The spectrum amplitude and the spectrum linewidth are calculated based on at least two sets of derivative relationships.

[0057] In a second aspect, an embodiment of the present application provides a clock circuit, comprising: a microwave output module and a control module; wherein the control module is used to execute the steps in the above-mentioned clock control method.

[0058] In a third aspect, an embodiment of the present application provides an electronic device, including: the above-mentioned clock circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0059] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without creative work.

[0060] Figure 1 A schematic diagram of a clock circuit provided in an embodiment of the present application;

[0061] Figure 2 Another schematic diagram of a clock circuit provided in an embodiment of the present application;

[0062] Figure 3 A flowchart of the clock control method provided in an embodiment of the present application;

[0063] Figure 4 An optional flowchart of step 260 of the clock control method provided in an embodiment of the present application;

[0064] Figure 5 A schematic diagram of a derivative curve provided in an embodiment of the present application;

[0065] Figure 6 A schematic diagram of a feedback loop used in the clock control method provided in an embodiment of the present application;

[0066] Figure 7 A schematic diagram of a transfer function curve provided in an embodiment of the present application.

[0067] Icons: 110-microwave output module; 111-crystal oscillator system; 112-transmitter module; 113-molecular gas chamber; 114-receiver module; 120-control module; 130-analog-to-digital converter; 140-digital-to-analog converter. DETAILED DESCRIPTION

[0068] The technical solutions in the embodiments of the present application will be described below in conjunction with the accompanying drawings in the embodiments of the present application.

[0069] It should be noted that similar reference numerals and letters represent similar items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further defined or explained in subsequent drawings. At the same time, in the description of this application, the terms "first", "second", etc. are only used to distinguish the description and should not be understood as indicating or implying relative importance.

[0070] In the description of this application, it should be noted that the terms "upper", "lower", "inside", "outside", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, or are orientations or positional relationships that are commonly used when the inventive product is used. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be interpreted as a limitation of this application.

[0071] It should also be noted that, in the description of this application, unless otherwise expressly specified or limited, the terms "disposed," "installed," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; mechanical connections, electrical connections; direct connections, indirect connections through an intermediate medium, and internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on the specific circumstances.

[0072] At present, high-precision clocks mainly include atomic clocks and molecular clocks. Atomic clocks use the interaction between electromagnetic radiation and the excited state of specific atoms to achieve time measurement, and the absorption peak generated by the laser penetrating the glass gas chamber is used as a frequency reference. Molecular clocks use the electromagnetic wave molecular rotation spectrum generated by the quantized rotational energy level transition of polar gas molecules under the action of the electromagnetic field to achieve time measurement. Molecular clocks use the rotation spectrum peak of the polar gas penetrating the gas chamber with high-frequency electromagnetic waves as a frequency reference. Compared with atomic clocks, the structure of molecular clocks is relatively simpler, but it can also achieve more accurate timing. However, the current implementation of atomic clocks usually uses a digital processor and PID (proportional-integral-differential) control method, but the modulation frequency of this atomic clock implementation method is low and is not suitable for use in molecular clocks.

[0073] Based on this, the present application provides a clock control method, a clock circuit, and an electronic device including the clock circuit. Through combined control of two sets of Q signals, the clock can be more flexibly controlled, thereby improving the clock output stability. The clock control method provided by the present application is described below in conjunction with embodiments.

[0074] For ease of understanding, this application first introduces a clock circuit used to execute the clock control method.

[0075] like Figure 1 As shown, the clock circuit may include a microwave output module 110 and a control module 120. The control module 120 may be used to process the microwave signal output by the microwave output module 110.

[0076] In this embodiment, Figure 2 As shown, the microwave output unit 110 includes a transmitting module 112 for outputting microwave signals.

[0077] The transmitting module 112 can serve as a frequency synthesis system. The transmitting module 112 synthesizes the reference clock signal through frequency synthesis and outputs a microwave signal close to the molecular resonance frequency to the molecular gas chamber 113. For example, the transmitting module 112 can also apply center frequency scanning and frequency modulation to the microwave frequency signal.

[0078] Exemplarily, the transmitting module 112 may include a phase-locked loop circuit and a first mixer.

[0079] The phase-locked loop circuit can receive a reference clock from a molecular clock as an input signal to the phase-locked loop circuit. The output signal of the phase-locked loop circuit can serve as a local oscillator input signal for a first mixer. The first mixer mixes the local oscillator input signal with an intermediate frequency input signal to obtain an output signal of the first mixer, which can serve as a microwave signal output by the transmitting module 112.

[0080] Taking the microwave output unit 110 including the crystal oscillator system 111 as an example, the crystal oscillator system 111 can output a reference clock, and the reference clock can be input into a phase-locked loop circuit as an input signal of the phase-locked loop circuit.

[0081] In this embodiment, the intermediate frequency input signal input to the first mixer may be a low-frequency signal with a frequency modulation function. The first mixer is further configured to mix the output signal of the phase-locked loop circuit with the intermediate frequency input signal obtained by N-th order modulation, thereby obtaining an Nth harmonic signal output by the first mixer.

[0082] Exemplarily, the first mixer is also used to receive the control of the control module 120, and mix the output signal of the phase-locked loop circuit with the intermediate frequency input signal based on the first frequency as the frequency step, the first time as the single step time, the preset number of points as the scanning point number and the preset starting frequency to output a center frequency signal.

[0083] Exemplarily, the intermediate frequency input signal may be generated by a digital frequency synthesizer (Direct Digital Synthesizer, DDS for short).

[0084] In this embodiment, the transmitting module 112 can also frequency modulate the microwave signal to output multiple harmonic signals of the modulation frequency with adjustable phase. For example, the transmitting module 112 can modulate the frequency of the intermediate frequency input signal, mix the local oscillator input signal with the modulated intermediate frequency input signal, and obtain the output signal of the first mixer to output an Nth harmonic signal.

[0085] Optionally, the frequency modulation used by the transmitting module 112 may be sinusoidal frequency modulation. When the frequency modulation is enabled, sinusoidal frequency modulation may be performed with a preset modulation frequency and a preset maximum frequency deviation to obtain a modulation frequency signal.

[0086] The preset modulation frequency can be expressed as f m ;The maximum frequency deviation can be expressed as v D , the frequency modulation output frequency value can be expressed as: v m (t) = v D sin(2πf m t+φ0); where φ0 represents the initial phase of the modulation control signal.

[0087] In this embodiment, when the frequency modulation is not enabled, the frequency modulation output frequency can be expressed as:

[0088] v m (t)=0.

[0089] When the center frequency scan is started, the transmitting module 112 of the microwave output unit 110 can obtain a center frequency signal based on the first frequency as the frequency step, the first time as the single step time, the preset number of points as the scanning point number and the preset starting frequency.

[0090] Optionally, the center frequency signal may be in the range of 1 GHz to 1 THz. For example, the center frequency signal may be 1 GHz, 10 GHz, 1 THz, or the like. In one example, for OCS gas, the center frequency signal may be 12.16 GHz*K, where K is a positive integer. Of course, when using other molecular gases, the range of the center frequency signal outputted for these molecules may be different.

[0091] Optionally, the transmitting module 112 can perform single or multiple scans according to a sawtooth wave based on the first frequency as frequency step, the first time as single step time, the preset number of points as scanning points and the preset starting frequency to obtain a center frequency signal.

[0092] For example, the first frequency as a frequency step can be expressed as δν; the first time as a single step time can be expressed as δt; the number of scanning points can be expressed as N sweep ; The starting frequency can be expressed as v strat .

[0093] When the center frequency scan is started, the i-th scan frequency point can be expressed as:

[0094] v sweep，i =v strat +(i-1)δv,i∈[1,N sweep ]. The real-time center frequency sweep output frequency value can be expressed as: Where t0 is the start time of the scan.

[0095] In this embodiment, when the center frequency scanning switch is off, v sweep (t)=0.

[0096] Optionally, the center frequency scanning and frequency modulation characteristics may be controlled by the control module 120. For example, the control module 120 may send a signal to the transmitting module 112 of the microwave output unit 110 to control whether the transmitting module 112 starts center frequency scanning.

[0097] In this embodiment, the center frequency of the transmitting module 112 is the center frequency value v0, the center frequency scanning output frequency value v sweep (t) and the frequency modulation output frequency value v m The sum of (t) is expressed as:

[0098] v(t)=v0+vsweep (t)+v m (t).

[0099] For example, v0 can be adjusted to be within the absorption spectrum of the molecule.

[0100] Optionally, the center frequency value v0 may also be updated according to the result of the spectrum sweep process.

[0101] Exemplarily, a spectrum curve is obtained during the frequency scanning process. By calculating the spectrum line amplitude estimate of the spectrum curve, it is determined whether the spectrum line amplitude estimate is less than the preset threshold. If the spectrum line amplitude estimate is less than the preset threshold, it means that the center frequency value v0 is within the molecular absorption spectrum range, and the estimated value of the molecular resonance frequency is determined to be the center frequency value v0.

[0102] For example, the peak value of the spectrum curve may be used as the estimated value of the spectrum line amplitude.

[0103] For example, the estimated value of the molecular resonance frequency can be determined as follows: the spectrum signal value P(v0+v sweep，i ), for each spectrum signal value P(v0+v sweep，i ) is used to perform curve fitting to obtain a curve formed by P(v) relative to v. A parameter in the parameter sequence in P(v) is used to represent the molecular resonance frequency, and the value of this parameter is used as the estimated value of the molecular resonance frequency.

[0104] Through the above implementation, the transmitting module can realize the output of modulated microwave signals, thereby outputting multiple harmonic signals to obtain a data basis for the subsequent determination of multi-order derivative error signals, improve the suppression of spectral baseline drift, and improve the long-term frequency stability of the clock.

[0105] In this embodiment, Figure 2 As shown, the microwave output unit 110 includes a receiving module 114 for detecting the microwave signal obtained by scanning to obtain a detection signal.

[0106] The receiving module 114 can serve as a detection system. The receiving module 114 receives the microwave frequency signal output by the molecular gas chamber 113 of the microwave output unit 110 and obtains a detection signal having a frequency positively correlated with the power of the received signal through detection.

[0107] Exemplarily, the receiving module 114 includes a voltage-controlled oscillator, a second mixer, and an envelope detector.

[0108] The output signal of the voltage-controlled oscillator serves as the local oscillator input signal of the second mixer; the microwave signal received by the receiving module 114 serves as the radio frequency input signal of the second mixer; the second mixer mixes the local oscillator input signal and the radio frequency input signal and outputs the mixed signal to the envelope detector; the envelope detector detects the received signal and outputs it as the detection signal.

[0109] Optionally, the output signal of the voltage-controlled oscillator may also be used as the local oscillator input signal of the second mixer after frequency multiplication.

[0110] Optionally, the second mixer may perform mixing processing on the local oscillator input signal and the radio frequency input signal and then transmit the mixed signals to the envelope detector.

[0111] Optionally, the envelope detector may be used to detect and obtain a signal that is positively correlated with the power of the received signal.

[0112] By implementing the above-mentioned receiving module and the detection processing provided by the envelope detector, the microwave signal can be detected, and the output signal can be proportional to the peak value of the input signal.

[0113] In this embodiment, Figure 2 As shown, the microwave output unit 110 may further include a crystal oscillator system 111 and a molecular gas chamber 113 .

[0114] The crystal oscillator system 111 can be connected to the transmitter module 112 and configured to output a crystal oscillator signal to the transmitter module 112. The transmitter module 112 is further configured to output a frequency signal based on the crystal oscillator signal. For example, the crystal oscillator signal output by the crystal oscillator system 111 can be used as a reference clock and input to the transmitter module 112, which processes it as a reference signal.

[0115] Optionally, the crystal oscillator system 111 may include a crystal oscillator and a frequency synthesis system. The crystal oscillator system 111 is used to output a frequency signal. The frequency synthesis system can convert the frequency signal output by the crystal oscillator into a suitable frequency and output it as a clock signal and a reference clock.

[0116] The molecular gas chamber 113 is connected between the transmitting module 112 and the receiving module 114 , and is used for resonantly absorbing microwaves of a specific frequency of the frequency signal of the transmitting module 112 , and transmitting the processed microwave signal to the receiving module 114 .

[0117] Optionally, the molecular gas chamber 113 can be a sealed cavity with microwave coupling windows, connected by a microwave waveguide. Exemplarily, the molecular gas chamber 113 can include two microwave coupling windows, one of which can serve as a receiving window and the other as a transmitting window. Exemplarily, the molecular gas chamber 113 can also include only one window, which can be used for both transmitting and receiving signals.

[0118] Exemplarily, the specific frequency may represent a molecular resonance frequency.

[0119] For example, the molecular gas chamber 113 is filled with molecular gas at a certain pressure. The transition between the rotational energy levels of the molecules causes the molecules to resonate and absorb microwaves with a frequency close to the molecular resonance frequency.

[0120] Optionally, the control module 120 may be implemented by a control chip that can perform data calculations. For example, the control chip may be a processor with data processing capabilities.

[0121] Optionally, the signal output by the microwave output module 110 may be an analog signal, and a converter may be connected between the control chip and the microwave output module 110. The converter may convert the analog signal output by the microwave output module 110 into a digital signal and transmit it to the control chip; the digital signal output by the control chip may be converted into an analog signal and transmitted to the microwave output module 110 to regulate the clock signal output by the microwave output module 110.

[0122] For example, Figure 2 As shown, the converter may include an analog-to-digital converter 130 and a digital-to-analog converter 140 .

[0123] Optionally, the control module 120 may also be implemented by a control circuit capable of processing analog signals, which may include a demodulation circuit and a control circuit. The demodulation circuit performs data demodulation, and the control circuit performs feedback control based on the demodulated signal.

[0124] Exemplarily, the demodulation circuit can be implemented by a lock-in amplifier module, and the control circuit can be implemented by a feedback circuit. The lock-in amplifier module can include a lock-in amplifier. The feedback circuit can include components such as an integrator, a proportional amplifier, and an adder. The integrator, the proportional amplifier, and the adder can be used to process the signal output by the lock-in amplifier module.

[0125] In this embodiment, the microwave output module is connected to both the lock-in amplifier and the feedback circuit. The microwave output module can output a microwave signal and an Nth harmonic signal to the lock-in amplifier. The feedback circuit can be connected to the lock-in amplifier to obtain the signal output by the lock-in amplifier.

[0126] In this embodiment, the lock-in amplifier is used to determine an I signal and a Q signal based on the Nth harmonic signal and the detection signal determined by the microwave output unit 110. The Q signal can be used as a derivative error signal. The I signal and Q signal determined based on the Nth harmonic signal and the detection signal are Nth-order signals.

[0127] Optionally, if it is necessary to output multiple derivative error signals of different orders, multiple lock-in amplifiers can be used to operate synchronously to obtain multiple derivative error signals of different orders.

[0128] Wherein, N is a positive integer.

[0129] In one example, when clock control is required to be implemented with a first-order derivative error signal and a third-order derivative error signal, two lock-in amplifiers may be provided, wherein one lock-in amplifier is used to obtain the first-order derivative error signal, and the other lock-in amplifier is used to obtain the third-order derivative error signal.

[0130] Of course, based on different actual processing scenarios or different selections of the order of the Q signal, the clock circuit may include more lock-in amplifiers.

[0131] For example, if more sets of Q signals are needed, a larger number of lock-in amplifiers can be provided. For example, if two sets of Q signals need to be output, two lock-in amplifiers can be provided to calculate the two Q signals respectively. For example, if three sets of Q signals need to be output, three lock-in amplifiers can be provided to calculate the two Q signals respectively.

[0132] The clock control method that can be implemented by the above-mentioned clock circuit will be described below through some embodiments. Figure 3 This is a flow chart of the clock control method provided in the embodiment of the present application. Figure 3 As shown, the clock control method may include the following steps.

[0133] Exemplarily, the clock control method may be implemented by a control module in a clock circuit.

[0134] Step 220: Use the M1 subharmonic signal as the local oscillator signal, perform component processing on the detection signal, and obtain a first Q signal.

[0135] Among them, the M1 harmonic signal and the detection signal are output by the clock circuit.

[0136] Exemplarily, the M1 subharmonic signal may be outputted by the clock circuit in a frequency modulation manner, which may be sinusoidal frequency modulation.

[0137] For example, when the clock circuit starts frequency modulation, it can be modulated at a frequency f m , maximum frequency deviation v D Apply sinusoidal frequency modulation. When the frequency modulation is started, the frequency modulation output frequency value is v m (t) = v D sin(2πf mt+φ0), where φ0 is the initial phase of the modulation signal. When the frequency modulation is not started, the frequency modulation output frequency is v m (t)=0.

[0138] Exemplarily, the first Q signal may be a mapping of the detection signal on one of the coordinate axes in a two-dimensional coordinate system.

[0139] Step 240: Use the M2 subharmonic signal as the local oscillation signal, perform component processing on the detection signal, and obtain a second Q signal.

[0140] In this embodiment, the M2 harmonic signal is also output by the clock circuit.

[0141] Wherein, M2 and M1 are both positive integers, and M2 is not equal to M1.

[0142] Exemplarily, both M1 and M2 may be odd numbers, such as 1, 3, 5, 7, or 9. For example, M1 may be 1, and M2 may be 3.

[0143] Step 260: Process the first Q signal and the second Q signal to obtain a control signal.

[0144] The control signal is used to regulate the clock circuit to output a clock signal.

[0145] Optionally, the control signal may be converted into an analog control signal via a digital-to-analog converter, and the analog control signal is output to a crystal oscillator system to adjust the crystal oscillator frequency output, thereby realizing the clock signal of the clock circuit.

[0146] Illustratively, the clock circuit may include a crystal oscillator system, and the control signal may be used to be transmitted to the crystal oscillator system. The crystal oscillator system is regulated by the control signal to achieve regulation of the clock signal of the clock circuit.

[0147] In the above embodiment, by performing mixed processing on multiple groups of Q signals, a signal greater than the first harmonic can be used as the basis for determining the control signal, so as to achieve multiple harmonics to reduce the impact of the spectral baseline drift caused by the use of the clock on the calculation, thereby improving the long-term stability of the clock circuit.

[0148] In this embodiment, Figure 4 As shown, the above step 260 may include the following steps 261 to 263.

[0149] Step 261 : Perform gain processing on the first Q signal using a first gain coefficient to obtain a first gain signal.

[0150] Optionally, the first Q signal is integrated using a first gain coefficient to obtain a first gain signal.

[0151] Optionally, the first Q signal may be amplified using a first gain coefficient to obtain a first gain signal. The first gain coefficient may serve as an amplification factor of the first Q signal.

[0152] Step 262: Perform gain processing on the second Q signal using a second gain coefficient to obtain a second gain signal.

[0153] Optionally, the second Q signal is integrated using a second gain coefficient to obtain a second gain signal.

[0154] Optionally, the second Q signal may be amplified using a second gain coefficient to obtain a second gain signal. The second gain coefficient may serve as an amplification factor of the second Q signal.

[0155] Step 263: Obtain a control signal according to the first gain signal and the second gain signal.

[0156] In an optional implementation, the first gain signal, the second gain signal, and the bias signal may be summed to obtain a control signal.

[0157] Optionally, the bias signal is provided by the power supply of the clock circuit through resistor voltage division, or provided by a voltage reference chip connected to the clock circuit.

[0158] The bias signal may be a DC bias signal.

[0159] In this embodiment, the DC bias signal can make the difference between the initial value of the center frequency emitted by the transmitting module of the clock circuit and the molecular resonance frequency smaller than a preset value, which can be a relatively small value.

[0160] In an optional embodiment, the control signal can also be obtained by accumulating the first gain signal and the second gain signal step by step. For example, the control signal is determined by the following formula:

[0161] C i -C i-1 =-k P (E i，M1 -E i-1，M1 )-k I E i，M2 ;

[0162] Among them, C i represents the control signal corresponding to the i-th detection signal; C i-1 represents the control signal corresponding to the i-1th detection signal; k P represents the first gain coefficient; k I Represents the second gain coefficient; E i，M1 represents the first Q signal corresponding to the i-th detection signal; Ei-1，M1 represents the first Q signal corresponding to the i-1th detection signal; E i，M2 Represents the second Q signal corresponding to the i-th detection signal.

[0163] Taking the first Q signal as the first order and the second Q signal as the third order as an example, the control signal can be expressed as:

[0164] C i -C i-1 =-k P (E i，1 -E i-1，1 )-k I E i，3 ;

[0165] Among them, C i represents the control signal corresponding to the i-th detection signal; C i-1 represents the control signal corresponding to the i-1th detection signal; k P represents the first gain coefficient; k I Represents the second gain coefficient; E i，1 represents the first Q signal of the first order corresponding to the i-th detection signal; E i-1，1 represents the first Q signal of the first order corresponding to the i-1th detection signal; E i，3 It indicates that the i-th detection signal corresponds to the third-order second Q signal.

[0166] Since the control signal obtained by low-order Q signal processing is less affected by noise, a higher signal-to-noise ratio can be achieved, and the short-term frequency stability of the clock can be better achieved; and the high-order Q signal can reduce the influence of spectral baseline drift, improve the suppression of spectral baseline drift, and improve the spectral baseline drift caused by long-term use of the clock, thereby achieving long-term frequency stability of the clock. Based on this, one of the first Q signal and the second Q signal provided in the embodiment of the present application is a low-order Q signal, and one is a high-order Q signal. By setting the gain coefficient of the two Q signals to adjust the influence of the two Q signals on the clock control, the long-term stability and short-term stability of the clock can be better balanced.

[0167] Exemplarily, the first Q signal may be a low-order Q signal, such as a first-order Q signal, and the second Q signal may be a high-order Q signal, such as a third-order Q signal, a fifth-order Q signal, etc.

[0168] Exemplarily, the order of the Q signal can be determined by the local oscillator signal used in the calculation. For example, the order of the harmonic signal used in the local oscillator signal can be used. For example, the first Q signal determined by the M1th harmonic signal is an M1th-order Q signal; and the second Q signal determined by the M2th harmonic signal is an M2th-order Q signal.

[0169] In this embodiment, the first Q signal and the second Q signal can be processed respectively based on the first gain coefficient and the second gain coefficient to achieve separate gains for Q signals of different orders, which can better balance the impact of the two Q signals of different orders on the control signal to achieve control signal adjustment, thereby improving the stability of the clock circuit.

[0170] In an optional embodiment, the first gain coefficient is greater than zero, and the second gain coefficient is smaller than the first gain coefficient; or, the second gain coefficient is greater than zero, and the first gain coefficient is smaller than the second gain coefficient.

[0171] For example, if the signal-to-noise ratio requirement is high, the gain coefficient corresponding to the lower-order Q signal can be set to a larger value; if the influence of spectral baseline tilt needs to be better reduced, the gain coefficient corresponding to the higher-order Q signal can be set to a larger value.

[0172] Optionally, the first gain coefficient and the second gain coefficient may be set to different values ​​based on different requirements for short-term frequency stability and long-term frequency stability.

[0173] If only short-term frequency stability is required, the gain coefficient corresponding to the lower-order Q signal can be set to a larger value; if high long-term frequency stability is required, the gain coefficient corresponding to the higher-order Q signal can be set to a larger value.

[0174] In the above embodiment, by setting the relative sizes of the first gain coefficient and the second gain coefficient, the influence of the first Q signal and the second Q signal on the clock control can be adaptively adjusted, thereby achieving more flexible clock control to adapt to the clock regulation requirements in different states and improve the flexibility and stability of clock control.

[0175] Considering that the signal may contain DC and AC components, in order to reduce the interference of uncertain factors in signal calculation, the signal can be filtered to remove the AC component.

[0176] Step 221: Use the M1 subharmonic signal as the local oscillator signal to perform mixing processing on the detection signal to obtain a first initial Q signal.

[0177] Exemplarily, the first initial Q signal is determined by the following formula:

[0178] Q i，M1 =-P i ×sin(2πM1f m t+φ dem，M1 );

[0179] Among them, f m Indicates the modulation frequency used to determine the M1 harmonic signal; φ dem，M1 Indicates the demodulation phase of the M1 harmonic; P i represents the i-th detection signal in the detection signal sequence; Q i，M1 represents the first initial Q signal; t represents the frequency modulation start-up time.

[0180] Step 222: Filter the first initial Q signal to remove the AC component in the first initial Q signal to obtain a first Q signal.

[0181] Through the filtering process in step 222 , the AC component in the first initial Q signal can be filtered out to obtain the first Q signal.

[0182] Optionally, a low-pass filter may be used to filter out the AC component of the first initial Q signal.

[0183] Exemplarily, the low-pass filtering algorithm may include: using a cascaded integrator-comb (CIC) filter with a stage of 1, a decimation number of D, and a differential delay of 1.

[0184] Exemplarily, the first Q signal can be expressed as:

[0185]

[0186] Among them, δ lp，i，M1 represents a first Q signal, which can be obtained by averaging D consecutive first initial Q signals.

[0187] By selecting the demodulation phase, the value of the first initial Q signal can be made relatively larger. An optimal demodulation phase can be determined to obtain a larger first initial Q signal. Therefore, before step 220, the clock control method can also include steps 211 and 212.

[0188] Step 211 : Calculate the amplitude and phase of the signal curve at each scanning frequency point based on the M1 subharmonic signal and the detection signal.

[0189] The scanning frequency point is determined by configuring the scanning frequency condition during the process of the clock circuit outputting the microwave signal and is determined by the scanning frequency condition.

[0190] For example, the scanning frequency condition may include the limits of frequency step, single step time, number of scanning points, and starting frequency. For example, the scanning frequency condition may include the frequency step of δv, single step time of δt, and number of scanning points of N. sweep ; The starting frequency is ν strat .

[0191] For example, the amplitude and phase of the signal curve are calculated using the following formula:

[0192]

[0193] φ M1 (ν0+νs weep，i )=arg(I M1 (ν0+ν sweep，i )+iQ M1 (ν0+ν sweep，i ));

[0194] Among them, v sweep,i Indicates the i-th scanning frequency point; v0 indicates the center frequency value; I M1 (v0+v sweep，i ) indicates that at the scanning frequency point v sweep,i I signal under; Q M1 (v0+v sweep，i ) indicates that at the scanning frequency point v sweep,i Q signal under; A M1 (、v0+v sweep,i ) indicates that at the scanning frequency point v sweep,i The amplitude of the signal curve below; φ M1 (v0+v sweep，i ) indicates that at the scanning frequency point v sweep，i The next phase.

[0195] Step 212 : Select a target amplitude of the signal curve that meets a set condition from the amplitudes of the signal curve calculated at each scanning frequency point, and use the phase at the scanning frequency point where the target amplitude exists as the optimal demodulation phase.

[0196] The above-mentioned step 221 may include: according to the optimal demodulation phase, using the M1 subharmonic signal as the local oscillation signal, performing mixing processing on the detection signal, and obtaining the first initial Q signal.

[0197] Exemplarily, the first initial Q signal is implemented by the following formula:

[0198]

[0199] Among them, Q i,M1 represents the first initial Q signal; P i represents the i-th detection signal in the detection signal sequence; f m represents the modulation frequency; t represents the modulation duration; Indicates the optimal demodulation phase of the M1 harmonic.

[0200] The above-mentioned step 212 may include: determining a set of target scanning frequency points greater than the molecular resonance frequency from multiple scanning frequency points; and determining the signal curve with the largest amplitude as the target amplitude based on the amplitude of the signal curve of each target scanning frequency point in the set of target scanning frequency points.

[0201] The molecular resonance frequency is determined by the spectrum curve formed by the detection signal output by the clock circuit.

[0202] Optionally, the amplitude and phase of the signal curve used for the optimal demodulation phase required for the first Q signal are calculated using the following formula:

[0203]

[0204] φ M1 (v0+v sweep，i )=arg(I M1 (ν0+v sweep，i )+iQ M1 (v0+ν sweep，i ));

[0205] Among them, v sweep，i Indicates the i-th scanning frequency point; v0 indicates the center frequency value; I M1 (v0+v sweep，i ) indicates that at the scanning frequency point v sweep,i I signal under; Q M1 (v0+v sweep，i ) indicates that at the scanning frequency point v sweep,i Q signal under; A M1 (v0+v sweep,i ) indicates that at the scanning frequency point v sweep,i The amplitude of the signal curve below; φ M1 (v0+v sweep，i ) indicates that at the scanning frequency point v sweep，i The next phase.

[0206] Considering that the second initial signal may also contain DC and AC components, in order to reduce the interference of uncertain factors in signal calculation, the signal can be filtered to remove the AC component.

[0207] Step 241: Use the M2 harmonic signal as the local oscillator signal to perform mixing processing on the detection signal to obtain a second initial Q signal.

[0208] Exemplarily, the second initial Q signal is determined by the following formula:

[0209] Q i,M2 =-Pi ×sin(2πM2f m t+φ dem,M2 );

[0210] Among them, f m Indicates the modulation frequency used to determine the M2 harmonic signal; φ dem，M2 Indicates the demodulation phase of the M2 harmonic; P i represents the i-th detection signal in the detection signal sequence; Q i，M2 represents the second initial Q signal; t represents the frequency modulation start-up time.

[0211] Step 242: Filter the second initial Q signal to remove the AC component in the second initial Q signal to obtain a second Q signal.

[0212] Through the filtering process in step 242 , the AC component in the second initial Q signal can be filtered out to obtain the second Q signal.

[0213] Optionally, a low-pass filter may be used to filter out the AC component of the second initial Q signal.

[0214] Exemplarily, the low-pass filtering algorithm may include: using a cascaded integrator-comb (CIC) filter with a stage of 1, a decimation number of D, and a differential delay of 1.

[0215] Exemplarily, the second Q signal can be expressed as:

[0216]

[0217] Among them, δ lp，i，M2 The second Q signal is obtained by averaging D consecutive second initial Q signals.

[0218] By selecting the demodulation phase, the value of the second initial Q signal can be made relatively larger. An optimal demodulation phase can be determined to obtain a larger second initial Q signal. Therefore, before step 240, steps 231 and 232 may also be included.

[0219] Step 231 : At each scanning frequency point, the amplitude and phase of the signal curve are calculated based on the M2 subharmonic signal and the detection signal.

[0220] The scanning frequency point is determined by configuring the scanning frequency condition during the process of the clock circuit outputting the microwave signal and is determined by the scanning frequency condition.

[0221] Exemplarily, the scanning frequency condition may be the same as the scanning frequency condition used when determining the M1 subharmonic signal.

[0222] Step 232 : Select a target amplitude of the signal curve that meets a set condition from the amplitudes of the signal curve calculated at each scanning frequency point, and use the phase at the scanning frequency point where the target amplitude exists as the optimal demodulation phase.

[0223] The above-mentioned step 241 may include: according to the optimal demodulation phase, using the M2 harmonic signal as the local oscillation signal, performing mixing processing on the detection signal, and obtaining a second initial Q signal.

[0224] Exemplarily, the second Q signal is implemented by the following formula:

[0225]

[0226] Among them, Q i，M2 represents the second initial Q signal; P i represents the i-th detection signal in the detection signal sequence; f m represents the modulation frequency; t represents the modulation duration; Indicates the optimal demodulation phase of the M2 harmonic.

[0227] The above-mentioned step 232 may include: determining a set of target scanning frequency points greater than the molecular resonance frequency from multiple scanning frequency points; wherein the molecular resonance frequency is determined by a spectrum curve formed by a detection signal output by a clock circuit; and determining, based on the amplitudes of the signal curves of each target scanning frequency point in the set of target scanning frequency points, the signal curve with the largest amplitude as the target amplitude.

[0228] Optionally, the amplitude and phase of the signal curve used for the optimal demodulation phase required for the second Q signal are calculated using the following formula:

[0229]

[0230] φ M2 (v0+v sweep，i )=arg(I M2 (v0+v sweep，i )+iQ M2 (v0+v sweep，i ));

[0231] Among them, v sweep，i Indicates the i-th scanning frequency point; v0 indicates the center frequency value; I M2 (v0+v sweep，i ) indicates that at the scanning frequency point v sweep，i I signal under; Q M2 (v0+v sweep，i ) indicates that at the scanning frequency point v sweep，i Q signal under; A M2 (ν0+νsweep，i ) represents the scanning frequency point ν sweep，i The amplitude of the signal curve below; φ M2 (ν0+ν sweep，i ) at the scanning frequency point ν sweep，i The next phase.

[0232] Through the above method, it is possible to balance the requirements of short-term stability and long-term stability of the clock, and provide clock control needs that can better meet more scenarios.

[0233] Considering that harmonic signals of different orders have different effects on clock regulation, harmonic signals of different orders can be selected based on different requirements to achieve clock regulation.

[0234] Based on this, the clock control method of this embodiment may include steps 310 to 330 .

[0235] Step 310: Determine multiple sets of derivative relationships based on multiple harmonic signals and detection signals.

[0236] Each harmonic signal has a corresponding harmonic signal order, and each group of derivative relationships has a corresponding order.

[0237] Exemplarily, the derivative relationship determined based on the Nth harmonic signal and the detection signal may be an Nth-order derivative relationship.

[0238] The derivative relationship can be presented in the form of a calculation formula or in the form of a derivative curve.

[0239] Optionally, for each scanning frequency point, the mean of each Q signal of the Q signal sequence obtained at the scanning frequency point is calculated as the derivative error signal value; the derivative error signal value calculated at each scanning frequency point is curve fitted to obtain a derivative relationship with the scanning frequency point as the independent variable.

[0240] Take the Nth harmonic signal and determine the Nth order derivative curve as an example:

[0241] A third Q signal is calculated based on the Nth harmonic signal and the detection signal. The third Q signal can be used as an Nth-order derivative error signal.

[0242] Optionally, the calculation method of the third Q signal may be the same as the calculation method of the first Q signal and the second Q signal. For details, please refer to the description of the calculation process of the first Q signal and the second Q signal, which will not be repeated here.

[0243] Exemplarily, the N-order derivative error signal represented by the third Q signal can be expressed as:

[0244]

[0245]

[0246] Among them, f m Indicates the modulation frequency used to determine the Nth harmonic signal; represents the optimal demodulation phase of the Nth harmonic; P i represents the i-th detection signal in the detection signal sequence; Q i，N represents the third initial Q signal; t represents the frequency modulation start time; Q lp，i，N Indicates the third Q signal, the Q lp，i，N Can be used to represent the N-order derivative error signal E i，N .

[0247] Among them, Q lp，i，N It may be the average value of the D*(i-1)+1th third initial Q signal to the D*ith third initial Q signal.

[0248] At each scanning frequency point v sweep，i , calculate the scanning frequency point v sweep，i The N-order derivative error signals E under i，N The average value of the N-order derivative error signal value E at this frequency point N (v0+v sweep，i );

[0249] By scanning multiple frequency points v sweep，i And the scanning frequency point v sweep，i The corresponding N-order derivative error signal value E N (v0+v sweep，i ) to perform curve fitting and obtain the N-order derivative curve E N (v), where the E N (v) is a curve with respect to v as an Nth-order derivative curve. This Nth-order derivative curve is used to express the above-mentioned Nth-order derivative relationship.

[0250] In this embodiment, when N is an odd number, the Nth order derivative curve relative to the molecular resonance frequency v c It is an odd function, showing a dispersion line type, that is, the N-order dispersion curve. When N is an even number, the N-order derivative curve is relative to the molecular resonance frequency v c It is an even function, and the derivative curve can be used to monitor the spectral line amplitude.

[0251] Step 320 : For each set of derivative relationships, calculate the estimated value of the frequency discrimination efficiency according to the derivative relationship to obtain the estimated value of the frequency discrimination efficiency for each set of derivative relationships.

[0252] Optionally, a derivative value of the derivative relationship at a point where the molecular resonance frequency is located may be calculated, and the derivative value may be used as an estimated value of the frequency discrimination efficiency.

[0253] Among them, when the microwave frequency v is close to the molecular resonance frequency v c When the N-order derivative curve E N (v)≈0.

[0254] Based on this, we can calculate that when v=v c Department E N (v) The derivative k of v d , k d =E′ N (v c ); the k d As an estimate of the frequency discrimination efficiency.

[0255] Step 330: Determine the values ​​of M1 and M2 based on the estimated values ​​of the frequency discrimination efficiencies of each set of derivative relationships.

[0256] In this embodiment, by determining the relationship between the estimated value of the frequency discrimination efficiency and the order of the derivative curve, it can be understood that the estimated value of the frequency discrimination efficiency and the order of the derivative curve are in inverse proportion.

[0257] Based on the requirement of the frequency discrimination efficiency, appropriate M1 and M2 can be determined.

[0258] For example, if a higher frequency discrimination efficiency is required, a relatively low-order derivative curve and a derivative error signal can be selected to implement clock regulation. For example, if a lower frequency discrimination efficiency is required, a relatively high-order derivative curve and a derivative error signal can be selected to implement clock regulation.

[0259] For example, if it is necessary to balance the frequency discrimination efficiency through two different orders, then M1 and M2 can select a high-order and a first-order derivative curve and a derivative error signal to implement clock control.

[0260] In the above embodiment, by determining the estimated value of the demodulation efficiency, the influence of harmonic signals of different orders on the control effect can be better determined. The values ​​of M1 and M2 determined based on the estimated value of the demodulation efficiency can achieve modulation data that is more suitable for the molecular clock, thereby making the clock adjustment more accurate and stable.

[0261] The following is an analysis of the relationship between the frequency discrimination efficiency and the order of the derivative curve through some principles:

[0262] Define the molecular spectral line width as △v, and define the relative microwave frequency normalized by the spectral line width, y=v0+v sweep -v c .

[0263] The spectrum curve P(y) with y as the independent variable appears as an even function.

[0264] In this embodiment, the absorption spectrum of the molecule, after deducting the spectral baseline, is generally a Lorentzian line shape. P(y) is in the form: Where A represents the spectrum amplitude.

[0265] Define the Fourier transform Π(τ) of the spectral line function to the virtual frequency τ:

[0266]

[0267] After applying frequency modulation to the relative microwave frequency y, the time domain spectrum signal s(y,t) is expressed as: s(y,t)=P(y+m sinω0t); where m represents the modulation amplitude normalized by the spectrum linewidth. ω0 represents the modulation angular frequency, ω0=2*π*f m .

[0268] The Fourier transform ∑(τ, t) of the time domain spectrum signal s(y, t) to τ is:

[0269]

[0270] Using the time-shift characteristic of Fourier transform for the Fourier transform ∑(τ, t), we can get:

[0271] ∑(τ,t)=Π(τ)exp(imτsinω0t).

[0272] Using Jacobi-Anger expansion on the above formula, we can get:

[0273]

[0274] Among them, J n represents the nth-order Bessel function of the first kind.

[0275] Using the characteristics of Bessel function, J -n (z) = (-1) n J n (z), we can get the following formula:

[0276]

[0277] Then using the inverse Fourier transform, we can get:

[0278]

[0279] in:

[0280] The Fourier transform of the Lorentzian line spectrum is:

[0281] Π(τ)=-Aπexp(-|τ|);

[0282]

[0283] Using the Laplace transform of the Bessel function, we can get:

[0284]

[0285] Λ[J n (-mt)](p)=(-1) n Λ[J n (mt)](p);

[0286] Here, p represents the complex frequency.

[0287] Based on the Laplace transform of the above Bessel function, we can get:

[0288]

[0289] In this embodiment, a polynomial function can be defined, Then we can get:

[0290]

[0291]

[0292] When odd-numbered Nth harmonic demodulation is used and the demodulation phase is optimal:

[0293]

[0294]

[0295] In this embodiment, Figure 5 As shown in Figure 1, when m=1, the derivative curves of the first, second, third, fourth, and fifth harmonic signal demodulation are shown. Figure 5 In the example shown, the abscissa represents the relative microwave frequency to which the spectral line width is normalized, and the ordinate represents the value of the derivative error signal.

[0296] Through the above analysis and Figure 5 The derivative curve diagram shown in the figure shows that for the dispersion curve with an odd number N, the estimated value of the frequency discrimination efficiency is It can be determined that the estimated value of the frequency discrimination efficiency k d It decreases as N increases.

[0297] The bias of the derivative error signal may also affect the effect of clock control. Therefore, the values ​​of M1 and M2 may also be adjusted based on the bias of the derivative error signal.

[0298] The clock control method of this embodiment further includes steps 410 to 430 .

[0299] Step 410: construct a spectrum curve according to the detection signal.

[0300] Optionally, for each scanning frequency point, the mean of each detection signal of the detection signal sequence obtained at the scanning frequency point is calculated as the spectrum signal value; the spectrum signal value calculated at each scanning frequency point is curve fitted to obtain a spectrum curve with the scanning frequency point as the independent variable.

[0301] For example, when frequency modulation is not started, the center frequency scanning is started, and the scanning frequency point ν is scanned based on the scanning frequency condition. sweep，i Under these conditions, the average value of the detection signal is calculated as the spectrum signal value P(v0+v sweep，i ); The curve formed by P(v) relative to v is the measurement result of the spectrum, that is, the spectrum curve.

[0302] Step 420: Determine the spectrum line baseline based on the spectrum curve.

[0303] The spectral curve can be a spectral line baseline B(y) superimposed on the Lorentz line shape P(y).

[0304] The spectral baseline may be caused by waveguide transmission characteristics, amplifier gain, etc. The spectral baseline is usually a curve that changes slowly with frequency.

[0305] Step 430: Determine bias information based on the spectral baseline and the molecular resonance frequency.

[0306] The bias information may include information such as a normalized bias normalized to a relative frequency dimension and an amplitude of the normalized bias.

[0307] For example, B(y) can be represented by Taylor expansion near the center frequency of the spectrum line, and the following can be obtained:

[0308]

[0309] The coefficient of the spectral line baseline usually satisfies |b0|>>|b1||>>|b2|….

[0310] When the molecular clock is normally locked (y=0) and N is an odd number, the error signal bias E caused by the spectral baseline B(y) is b，N for:

[0311]

[0312] The normalized bias normalized to the relative frequency dimension is expressed as:

[0313] The magnitude of the normalized bias can be expressed as:

[0314]

[0315] The bias information may include normalized bias, the y b，N represents the normalized bias; E b，N Indicates the error bias caused by the spectral baseline; v C represents the molecular resonance frequency; m represents the modulation amplitude; k d，N Indicates the estimated value of the frequency discrimination efficiency corresponding to the N-th order derivative relationship.

[0316] Since m is usually close to 1, the magnitude of the normalized bias |y b，N The size of | mainly depends on |b N |. From this we can get the amplitude of the normalized bias |y b，N |Usually the order N of the derivative curve increases and decreases.

[0317] Step 330 may include determining the values ​​of M1 and M2 based on the bias information and the estimated values ​​of the frequency discrimination efficiencies of the respective groups of derivative relationships.

[0318] The amplitude of the normalized bias can directly reflect the drift of the spectral line baseline. The larger the amplitude of the normalized bias, the better the drift suppression of the spectral line baseline; the smaller the amplitude of the normalized bias, the worse the drift suppression of the spectral line baseline.

[0319] For example, if high frequency discrimination efficiency is required and the requirement for suppressing drift of the spectral baseline is low, a relatively low-order derivative curve and a derivative error signal can be selected to implement clock regulation. For example, if low frequency discrimination efficiency is required and the requirement for suppressing drift of the spectral baseline is high, a relatively high-order derivative curve and a derivative error signal can be selected to implement clock regulation.

[0320] In the above embodiment, by determining the estimated value of the discrimination efficiency and the bias information, the influence of harmonic signals of different orders on the control effect can be better determined. The values ​​of M1 and M2 determined based on the estimated value of the discrimination efficiency and the bias information can achieve modulation data that is more suitable for the molecular clock, thereby making the clock adjustment more accurate and stable.

[0321] In the embodiment of the present application, the power spectrum density may also be calculated to determine the values ​​of M1 and M2 based on the power spectrum density, bias information, and the estimated value of the frequency discrimination efficiency.

[0322] For example, it is assumed that the power spectrum density of the detection signal is expressed as S P (f). P(f) has nothing to do with the instantaneous microwave frequency. Here, f represents the frequency in the Fourier frequency domain.

[0323] Through the modulation and demodulation system, the power spectrum density on the error signal E(t) is expressed as, and the demodulation of the Nth harmonic can be determined:

[0324]

[0325] visible, It appears as white noise and is independent of the order N of the derivative curve.

[0326] The power spectrum density of the error signal E(t) determined above is only valid for f<<f bw efficient.

[0327] Normalized noise power spectral density S n，N (f) is the power spectral density of the relative frequency, which can be expressed as:

[0328]

[0329] For the N-order dispersion curve where N is an odd number, due to k d As N increases, it decreases, and the normalized noise power spectral density S can be determined. n，N (f) increases with the increase of N.

[0330] The height of the normalized noise power spectrum density can reflect the degree of noise impact, and the values ​​of M1 and M2 can be determined based on the normalized noise power spectrum density.

[0331] The appropriate M1 and M2 can be determined based on comprehensive considerations of the impact of noise levels and the requirements for frequency discrimination efficiency.

[0332] For example, if a high frequency discrimination efficiency is required and relatively low noise is required, a relatively low-order derivative curve and a derivative error signal can be selected to implement clock regulation. For example, if a low frequency discrimination efficiency is required and the influence of noise can be ignored, a relatively high-order derivative curve and a derivative error signal can be selected to implement clock regulation.

[0333] For example, if it is necessary to balance the frequency discrimination efficiency through two different orders, then M1 and M2 can select a high-order and a first-order derivative curve and a derivative error signal to implement clock control.

[0334] For example, the effects of two different orders may be different, and the frequency discrimination efficiency, noise impact, and spectral line baseline drift suppression may be balanced by adjusting the two M1 and M2. For example, the M1 and M2 may select a first-order derivative curve of a higher order and a derivative error signal to implement clock control.

[0335] The following is an analysis of clock stability based on some principles.

[0336] Since under normal frequency locking, the spectrum sweep frequency is v sweep = 0. The center frequency of the clock circuit's transmitter module is close to the center frequency of the spectrum. Near the center frequency of the spectrum, the Nth-order dispersion error curve can be linearly approximated and expressed as:

[0337] E N (y) = E b，N +k d，N v c y;

[0338] Taking noise into account, the N-order dispersion error curve can be expressed as:

[0339] E N (y, t) = E b，N +k d，N v c y+E n，N (t);

[0340] Among them, k d，N represents the estimated value of the frequency discrimination efficiency corresponding to the N-order derivative curve, and k d，N As the order N of the N-order derivative curve increases, it decreases. It can be determined that as |E b，N | / k d，N Reduce Increase.

[0341] The normalized error signal is defined as:

[0342]

[0343] Among them, y b，N =|E b，N | / k d，N represents the normalized bias, represents the normalized noise.

[0344] like Figure 6 As shown in the figure, the first-order derivative error signal is used as P feedback, and the third-order derivative error signal is used as I feedback for the hybrid PID control feedback loop. Figure 6 The feedback loop shown includes a plurality of adding blocks and subtracting blocks.

[0345] exist Figure 6 In the examples shown, Laplace transform is used for representation.

[0346] where Y ref (s) represents the relative frequency deviation of the molecule; G1(s) and G2(s) represent the open-loop transfer functions of the feedback control system; Represent the normalized noise of the two error signals respectively;

[0347] Respectively represent the normalized bias of the two error signals; Y n，osc (s) represents the relative frequency deviation of the free-running crystal oscillator; Y(s) represents the relative frequency deviation of the controlled crystal oscillator.

[0348] y ref (t), y n，osc (t) and y(t) represent the time domain respectively.

[0349] in, Figure 6 In the example shown, N1=1, N2=3, in and represents the normalized loop gain.

[0350] The loop equation can be expressed as:

[0351]

[0352]

[0353] in, is the closed-loop transfer function; is the noise transfer function.

[0354] The relationship between the noise power spectral density is:

[0355]

[0356] Among them, S(f), S ref (f) S n，osc (f) are y(t), y ref (t), y n，osc The power spectrum density of (t). Among them, each transfer function curve can be as follows Figure 7 As shown in FIG. 8 , the Y-axis of the curve represents the transfer function value, and the X-axis represents the frequency.

[0357] For example, the loop bandwidth of the clock is expressed as f bw , the f bw To satisfy The loop bandwidth can be obtained by numerically solving the equation.

[0358] At the low frequency end (f<<f bw ), approximately:

[0359] At the high frequency end (f>>f bw ), approximately:

[0360]

[0361] Based on the above analysis, it can be determined that at low frequencies, the feedback loop performs the same as when only the third-order derivative error signal, I, is fed back. At low frequencies, the loop also performs the same as when only the first-order derivative error signal, P, is fed back. Compared to PI feedback using only the third-order derivative error signal, the fact that the normalized noise power spectral density of the first-order derivative error signal is lower than that of the third-order derivative error signal can be exploited to reduce high-frequency noise.

[0362] By measuring S ref (f) S n，osc (f), the clock output power spectrum density S(f) can be calculated. The Allan variance (i.e. frequency stability) can be obtained by transformation. It can also be measured in real time while the clock circuit is running.

[0363] The steady-state relative frequency deviation can be expressed as:

[0364] It can be seen that the trend of the steady-state relative frequency deviation can be expressed as a normalized offset from the third-order derivative error signal. Compared to PI feedback using only the first-order derivative error signal, the relatively small normalized offset of the third-order derivative error signal can be used to achieve clock stability.

[0365] In this embodiment, the clock signal can be controlled by odd-order derivative error signals, and the even-order derivative error signals can be used for loop gain and spectrum linewidth detection.

[0366] In one embodiment, at least two sets of derivative relationships are determined based on multiple harmonic signals and the detection signal; wherein the orders of at least two sets of derivative relationships are even numbers; and the spectral amplitude and spectral linewidth are calculated based on the at least two sets of derivative relationships.

[0367] In one example, the second-order derivative error signal can be used to implement loop gain and spectral linewidth detection.

[0368] For example, the modulation amplitude is usually close to 1, and the modulation amplitude m can be set to 1, and the spectrum linewidth can be expressed as:

[0369]

[0370] When the working environment of the clock circuit changes, the spectrum line width may also change. When the clock circuit is in the locked state, the spectrum amplitude A and spectrum line width can be calculated by combining any two even-order derivative error signals.

[0371] In one example, the second-order derivative error signal and the fourth-order derivative error signal can be used to calculate the spectrum amplitude A and the spectrum linewidth Δv. For example, the formula constructed by the second-order derivative curve and the fourth-order derivative curve can be expressed as:

[0372]

[0373] Based on the above formula, the spectrum amplitude A and spectrum linewidth △v can be expressed as:

[0374]

[0375] The above implementation method can achieve measurement of high-order derivative curves with N>1 and obtain high-order derivative error signals. Based on the high-order derivative error signals, spectral baseline drift suppression can be improved, thereby improving the long-term frequency stability of the clock. Furthermore, it is possible to jointly control multi-order derivative error signals based on the M1-order derivative curve and the M2-order derivative curve, thereby achieving high signal-to-noise ratio, improving spectral baseline drift suppression, and reducing the impact of crystal oscillator drift, thereby improving the short-term and long-term frequency stability of the clock. By estimating and calculating the frequency discrimination efficiency, the frequency discrimination performance of the N-order derivative curve and the clock frequency stability can be estimated. Furthermore, even-order derivative error signals can be used for loop gain and spectral linewidth detection functions.

[0376] This embodiment can be applied to molecular clock control, increasing the modulation frequency compared to atomic clock control. This improves the signal-to-noise ratio, thereby increasing the clock's frequency stability. This molecular clock application eliminates the need for a laser system. This allows for a simpler clock system structure, resulting in low cost, low power consumption, and high reliability. In this embodiment, multi-order dispersion error signals are collectively controlled, maintaining a high signal-to-noise ratio, improving spectral baseline drift suppression, and reducing the impact of crystal oscillator drift.

[0377] An embodiment of the present application provides an electronic device that may include a clock circuit. The clock circuit involved in this embodiment may be similar to the clock circuit provided in the previous embodiment. For other details of the clock circuit of this embodiment, reference may be made to the description in the previous embodiment and will not be repeated here.

[0378] Optionally, the electronic device may further include other components. It is understandable that based on different usage scenarios and actual needs of the electronic device, the electronic device may further include more different components.

[0379] Optionally, the electronic device may further include components such as a display screen and a positioning unit. The display screen may display time based on a clock signal output by the clock circuit.

[0380] The electronic device of this embodiment may be a device that requires a precision clock, for example, the electronic device may be a global navigator, a control device for controlling satellite orbital motion, etc.

[0381] The foregoing is merely an optional embodiment of the present application and is not intended to limit the present application. Various modifications and variations are possible for those skilled in the art. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present application shall be included within the scope of protection of the present application. It should be noted that similar reference numerals and letters represent similar items in the following figures. Therefore, once an item is defined in one figure, it does not need to be further defined or explained in subsequent figures.

[0382] The above description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of the present application. Therefore, the scope of protection of the present application should be based on the scope of protection of the claims.

Claims

1. A clock control method, characterized in that: include: Using the M1 subharmonic signal as a local oscillator signal, performing component processing on the detection signal to obtain a first Q signal; wherein the M1 subharmonic signal and the detection signal are output by a clock circuit; The M2 subharmonic signal is used as the local oscillator signal, and the detection signal is component-processed to obtain a second Q signal; wherein, M2 and M1 are both positive integers, and M2 is not equal to M1, and the M2 subharmonic signal is output by the clock circuit; The first Q signal and the second Q signal are processed to obtain a control signal; wherein the control signal is used to regulate the clock circuit to output a clock signal.

2. The method according to claim 1, characterized in that The processing of the first Q signal and the second Q signal to obtain a control signal includes: Performing gain processing on the first Q signal using a first gain coefficient to obtain a first gain signal; Performing gain processing on the second Q signal using a second gain coefficient to obtain a second gain signal; A control signal is obtained according to the first gain signal and the second gain signal.

3. The method according to claim 2, characterized in that The performing gain processing on the first Q signal using a first gain coefficient to obtain a first gain signal includes: The first Q signal is integrated using a first gain coefficient to obtain a first gain signal.

4. The method according to claim 2, characterized in that The performing gain processing on the second Q signal using a second gain coefficient to obtain a second gain signal includes: The second Q signal is amplified using a second gain coefficient to obtain a second gain signal.

5. The method according to any one of claims 2 to 4, characterized in that: The obtaining of a control signal according to the first gain signal and the second gain signal includes: The first gain signal, the second gain signal and the bias signal are summed to obtain a control signal; wherein the bias signal is provided by the power supply of the clock circuit through a resistor divider, or provided by a voltage reference chip connected to the clock circuit.

6. The method according to any one of claims 2 to 4, characterized in that: The control signal is determined by the following formula: C i -C i-1 =-k P (E i,M1 -E i-1,M1 )-k1E i,M2 ; Among them, C i represents the control signal corresponding to the i-th detection signal; C i-1 represents the control signal corresponding to the i-1th detection signal; k P represents the first gain coefficient; k I Represents the second gain coefficient; E i，M1 represents the first Q signal corresponding to the i-th detection signal; E i-1，M1 represents the first Q signal corresponding to the i-1th detection signal; E i，M2 Represents the second Q signal corresponding to the i-th detection signal.

7. The method according to any one of claims 2 to 4, characterized in that: The first gain coefficient is greater than zero, and the second gain coefficient is less than the first gain coefficient; or, The second gain coefficient is greater than zero, and the first gain coefficient is less than the second gain coefficient.

8. The method according to claim 1, characterized in that The method of using the M1 subharmonic signal as a local oscillator signal and performing component processing on the detection signal to obtain a first Q signal includes: The M1 subharmonic signal is used as the local oscillator signal, and the detection signal is mixed to obtain the first initial Q signal; The first initial Q signal is filtered to remove an AC component in the first initial Q signal to obtain a first Q signal.

9. The method according to claim 8, characterized in that The first initial Q signal is determined by the following formula: Q i,M1 =-P i ×sin(2πM1f m t+φ dem,M1 ); Among them, f m Indicates the modulation frequency used to determine the M1 harmonic signal; φ dem，M1 Indicates the demodulation phase of the M1 harmonic; P i represents the i-th detection signal in the detection signal sequence; Q i，M1 represents the first initial Q signal; t represents the frequency modulation start-up time.

10. The method according to claim 9, characterized in that The method further comprises: At each scanning frequency point, the amplitude and phase of the signal curve are calculated based on the M1 subharmonic signal and the detection signal; wherein the scanning frequency point is determined by configuring the scanning frequency condition during the process of the clock circuit outputting the microwave signal; From the amplitudes of the signal curves calculated at each scanning frequency point, a target amplitude of the signal curve that meets a set condition is selected, and the phase at the scanning frequency point where the target amplitude is located is used as the optimal demodulation phase; The method of using the M1 subharmonic signal as a local oscillator signal and performing frequency mixing processing on the detection signal to obtain a first initial Q signal includes: According to the optimal demodulation phase, the M1 subharmonic signal is used as the local oscillation signal, and the detection signal is mixed to obtain the first initial Q signal.

11. The method according to claim 10, characterized in that The step of selecting a target amplitude of the signal curve that satisfies a set condition from the amplitudes of the signal curves calculated at the respective scanning frequency points comprises: Determining a set of target scanning frequency points greater than a molecular resonance frequency from the plurality of scanning frequency points; wherein the molecular resonance frequency is determined by a spectrum curve formed by a detection signal output by the clock circuit; According to the amplitudes of the signal curves of the target scanning frequency points in the set of target scanning frequency points, the signal curve with the largest amplitude is determined as the target amplitude.

12. The method according to claim 10, characterized in that The amplitude and phase of the signal curve are calculated using the following formula: φ M1 (v0+v sweep，i )=arg(I M1 (v0+v sweep,i )+iQ M1 (v0+v sweep，i )); Among them, ν sweep，i Indicates the i-th scanning frequency point; ν0 indicates the center frequency value; I M1 (ν0+ν sweep，i ) indicates that at the scanning frequency point v sweep,i I signal under; Q M1 (v0+v sweep,i ) represents the scanning frequency point ν sweep，i Q signal under; A M1 (ν0+ν sweep，i ) represents the scanning frequency point ν sweep，i The amplitude of the signal curve below; φ M1 (v0+v sweep,i ) at the scanning frequency point v sweep,i The next phase.

13. The method according to claim 1, wherein The method of using the M2 subharmonic signal as a local oscillator signal and performing component processing on the detection signal to obtain a second Q signal includes: The M2 harmonic signal is used as the local oscillator signal to mix the detection signal to obtain the second initial Q signal; The second initial Q signal is filtered to remove an AC component in the second initial Q signal to obtain a second Q signal.

14. The method according to claim 1, wherein The method further comprises: Determining multiple groups of derivative relationships based on multiple harmonic signals and the detection signal; wherein each harmonic signal has a corresponding order of the harmonic signal, and each group of derivative relationships has a corresponding order; For each set of derivative relationships, calculating a discrimination efficiency estimate value thereof according to the derivative relationship, so as to obtain a discrimination efficiency estimate value of each set of derivative relationships; The values ​​of M1 and M2 are determined based on the estimated values ​​of the frequency discrimination efficiency of each group of derivative relationships.

15. The method according to claim 14, characterized in that The method further comprises: constructing a spectrum curve according to the detection signal; Based on the spectrum curve, determining a spectrum line baseline; Determining bias information based on the spectral line baseline and the molecular resonance frequency; Determining the values ​​of M1 and M2 based on the estimated values ​​of the frequency discrimination efficiency of each group of derivative relationships includes: The values ​​of M1 and M2 are determined according to the bias information and the estimated values ​​of the frequency discrimination efficiency of each group of derivative relationships.

16. The method according to claim 15, characterized in that The constructing of a spectrum curve according to the detection signal comprises: For each scanning frequency point, calculate the mean value of each detection signal of the detection signal sequence obtained at the scanning frequency point as the spectrum signal value; Curve fitting is performed on the spectrum signal values ​​calculated at each scanning frequency point to obtain a spectrum curve with the scanning frequency point as an independent variable.

17. The method according to claim 15, characterized in that The bias information is determined by the following formula: Among them, y b，N Indicates bias information; E b，N Indicates the error bias caused by the spectral baseline; v c represents the molecular resonance frequency; m represents the modulation amplitude; k d，N Indicates the estimated value of the frequency discrimination efficiency corresponding to the N-th order derivative relationship.

18. The method according to claim 14, characterized in that The determining of multiple groups of derivative relationships based on the multiple harmonic signals and the detection signal includes: For each scanning frequency point, calculate the mean value of each Q signal of the Q signal sequence obtained at the scanning frequency point as the derivative error signal value; Curve fitting is performed on the derivative error signal value calculated at each scanning frequency point to obtain a derivative relationship with the scanning frequency point as an independent variable.

19. The method according to claim 14, wherein The calculating the estimated value of the frequency discrimination efficiency according to the derivative relationship includes: The derivative value of the derivative relationship at the point where the molecular resonance frequency is located is calculated, and the derivative value is used as an estimated value of the frequency discrimination efficiency.

20. A clock circuit, characterized in that: include: Microwave output module and control module; The control module is used to execute the steps in the clock control method according to any one of claims 1 to 19.

21. An electronic device, characterized in that: include: The clock circuit according to claim 20.

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