Radio frequency state detection circuit and method based on diamond nv color center sensor

Abstract

This invention provides a radio frequency (RF) status detection circuit and method based on a diamond NV color center sensor. First, in response to an initial calibration command, a calibration fluorescence sequence is acquired and fitted to obtain a reference magnetic field strength and a reference oscillation frequency. Then, based on a preset acquisition period, a first fluorescence sequence is acquired in real time, and a first magnetic field strength and a first oscillation frequency are calculated. The absolute deviations of the first magnetic field strength from the reference magnetic field strength and the absolute deviations of the first oscillation frequency from the reference oscillation frequency are then calculated. The obtained deviations are compared with a preset grading threshold group to determine the status level. Based on the status level, a protection action command is output and executed. The updated status level is then acquired, and a protection action adjustment command is generated accordingly. This invention achieves accurate perception of the RF circuit status through non-contact magnetic field detection, realizing full-process control from anomaly identification to adaptive protection without affecting the original circuit matching performance.

Description

Technical Field

[0001] This invention belongs to the field of radio frequency circuit detection. More specifically, this invention discloses a radio frequency state detection circuit and method based on a diamond NV color center sensor. Background Technology

[0002] With the rapid development of technologies such as radio frequency communication, radar detection, and wireless power transmission, the operating frequency of radio frequency circuits is constantly increasing and their integration level is continuously rising. The stability and reliability of their operating status are increasingly becoming the core focus of system design.

[0003] The performance of radio frequency (RF) circuits depends on their impedance matching; good matching leads to higher gain, higher efficiency, and higher bandwidth. Adding detection circuits to monitor abnormal states alters the impedance matching of the original circuit. This not only degrades the gain and efficiency of the original circuit but, more importantly, also changes the circuit's state, making it impossible to detect the true state. Therefore, a technique is urgently needed to detect the circuit state without affecting its original impedance matching.

[0004] It is worth mentioning that the diamond NV color center technology uses diamond as a sensor. Because its non-metallic material does not affect the magnetic field state of the original circuit, and it has no electrical connection with the original circuit, it will not change the circuit matching. Summary of the Invention

[0005] In view of the above problems, the purpose of this invention is to provide a radio frequency (RF) status detection circuit and method based on a diamond NV color center sensor. Through the overall process of establishing reference data through initial calibration, real-time acquisition and calculation of magnetic field status, comparison of graded thresholds to determine the status level, and closed-loop feedback to adjust the protection action, non-contact detection and adaptive protection of the RF circuit status are achieved.

[0006] Specifically, firstly, a reference oscillation frequency is obtained through a frequency sweep mode, and a reference magnetic field strength is obtained through a pulsed microwave mode, thus ensuring the accuracy of the reference data. Subsequently, a real-time oscillation frequency is obtained through narrowband frequency sweep, and a real-time magnetic field strength is obtained through pulsed microwave measurement, thereby achieving real-time tracking of changes in the magnetic field state. Secondly, by setting multiple levels of magnetic field thresholds and frequency thresholds and comparing them step by step, graded state identification from the normal zone to the warning zone and then to the danger zone is achieved. Then, through the differentiated design of the intensity graded output in the warning zone and the hardware latched output in the danger zone, graded protection response from fine adjustment to emergency shutdown is achieved. Finally, through a closed-loop feedback mechanism based on the trend and continuity of state changes, adaptive optimization adjustment of protection actions is achieved, effectively balancing system safety and operational continuity.

[0007] To achieve the above objectives, a first aspect of the present invention provides a radio frequency state detection circuit based on a diamond NV color center sensor, the detection circuit comprising: The signal processing unit is used to analyze the digital signal of fluorescence, and after performing fitting, oscillation calculation and threshold comparison operations, it outputs protection instruction code. The laser driving unit receives the laser control signal from the signal processing unit and drives the laser to generate excitation light of a preset wavelength to irradiate the diamond NV color center probe. The microwave signal generating unit receives the microwave control signal from the signal processing unit and uses it to generate a microwave signal that excites the diamond NV color center. The photoelectric conversion and signal conditioning unit is used to collect the fluorescence intensity of the diamond NV color center, convert the optical signal into a digital signal, and transmit it to the signal processing unit. The protection execution interface unit receives the protection instruction code from the signal processing unit and outputs the protection action instruction to the control terminal of the radio frequency circuit.

[0008] In this solution, the laser driving unit further includes: Based on the laser control signal, a constant or modulated current is output to drive the laser; The laser wavelength of the laser is 532nm.

[0009] In this solution, the microwave signal generating unit further includes: Sweep frequency working mode and fixed frequency working mode; The frequency sweeping mode is used for ODMR spectral acquisition to obtain the center frequency of the resonance peak; The fixed-frequency operating mode is used for Rabi oscillation measurement to obtain the magnetic field strength.

[0010] In this solution, the photoelectric conversion and signal conditioning unit specifically includes: Photomultiplier tubes, transconductance amplifiers, programmable gain amplifiers, filters, and analog-to-digital converters; The photomultiplier tube converts the light intensity signal of the diamond NV color center into an analog current signal. The transconductance amplifier converts the current analog signal into a voltage analog signal; The programmable gain amplifier is used to adjust the range of acceptable fluorescence intensity. The filter is used to filter noise at a set frequency from the voltage analog signal; The analog-to-digital converter converts the voltage analog signal into a digital signal.

[0011] A second aspect of the present invention also provides a radio frequency (RF) status detection method based on a diamond NV color center sensor, applied in any of the above-described RF status detection circuits based on a diamond NV color center sensor, the method comprising: In response to the initial calibration command, a calibration fluorescence sequence is acquired; After Lorentz fitting the calibration fluorescence sequence, the reference magnetic field strength and reference oscillation frequency were extracted. Based on a preset acquisition cycle, the diamond NV color center probe is excited to acquire the first fluorescence sequence in real time. Based on the first fluorescence sequence, the first magnetic field strength and the first oscillation frequency are calculated. Calculate the absolute deviation between the first magnetic field strength and the reference magnetic field strength to obtain the magnetic field strength deviation; Calculate the absolute deviation between the first oscillation frequency and the reference oscillation frequency to obtain the oscillation frequency deviation; The state level is obtained by comparing the magnetic field strength deviation and the oscillation frequency deviation with a preset grading threshold group. Based on the stated status level, after outputting and executing the protection action command, the updated status level is obtained; Based on the updated status level, a protection action adjustment instruction is generated.

[0012] In this scheme, the step of extracting the reference magnetic field strength and reference oscillation frequency after Lorentz fitting of the calibration fluorescence sequence specifically includes: In response to the initial calibration command, the laser is controlled to excite the diamond NV color center probe; The microwave signal generating unit is controlled to perform frequency sweep within a preset frequency sweep range, and the fluorescence signal corresponding to each frequency sweep point is collected to obtain the first calibration fluorescence sequence. The first calibration fluorescence sequence was Lorentz-fitted, and the center frequency of the resonance peak was extracted as the reference oscillation frequency. The microwave signal generating unit is fixed at the reference oscillation frequency and acts on the diamond NV color center probe in pulsed microwave mode. Fluorescence signals corresponding to different microwave action times are collected to obtain the second calibration fluorescence sequence. The reference magnetic field strength is calculated by fitting the Rabi oscillation curve based on the second calibration fluorescence sequence.

[0013] In this scheme, the step of calculating the first magnetic field strength and the first oscillation frequency based on the first fluorescence sequence specifically includes: Based on a preset acquisition cycle, the laser is controlled to excite the diamond NV color center probe; The microwave signal generating unit is controlled to perform a narrowband frequency sweep in the neighborhood of the reference oscillation frequency, and the fluorescence signal corresponding to each sweep point is collected to obtain the first real-time fluorescence sequence. Based on the first real-time fluorescence sequence, Lorentz fitting is performed to extract the center frequency of the real-time resonance peak, which is used as the first oscillation frequency. The microwave signal generating unit is fixed at the first oscillation frequency and acts on the diamond NV color center probe in pulse microwave mode. Fluorescence signals corresponding to different microwave action times are collected to obtain the second real-time fluorescence sequence. The first magnetic field strength is calculated by fitting the Rabi oscillation curve based on the second real-time fluorescence sequence.

[0014] In this scheme, the step of comparing the magnetic field strength deviation and oscillation frequency deviation with a preset grading threshold group to obtain the state level specifically includes: The graded threshold group includes a first magnetic field threshold, a second magnetic field threshold, a first frequency threshold, and a second frequency threshold; When the magnetic field strength deviation is less than or equal to the first magnetic field threshold and the oscillation frequency deviation is less than or equal to the first frequency threshold, the state level is determined to be the normal zone. When the magnetic field strength deviation is greater than the first magnetic field threshold and less than or equal to the second magnetic field threshold, or when the oscillation frequency deviation is greater than the first frequency threshold and less than or equal to the second frequency threshold, the state level is determined to be a warning zone. When the magnetic field strength deviation is greater than the second magnetic field threshold, or the oscillation frequency deviation is greater than the second frequency threshold, the state level is determined to be a dangerous zone.

[0015] In this solution, the step of outputting and executing protection action commands based on the status level specifically includes: When the state level is the warning zone, calculate the ratio of the magnetic field strength deviation to the second magnetic field threshold, and the ratio of the oscillation frequency deviation to the second frequency threshold. Based on the larger of the intensity ratio and the frequency ratio, a power reduction request command or a matching network adjustment command is output and sent to the control terminal of the radio frequency circuit through the protection execution interface unit; When the status level is the danger zone, the output signal source shutdown command and bias power supply cut-off command are sent to the protection control node of the radio frequency circuit through the protection execution interface unit in a hardware latching manner.

[0016] In this solution, the step of generating protection action adjustment instructions based on the updated status level specifically includes: Update the obtained status level after receiving the protection action command; When the updated status level is in the normal zone and the number of consecutive normal occurrences reaches a preset threshold, a protection revocation action command is generated. When the updated status level is still in the warning zone, a command to maintain the current protection action or a command to increase the protection strength are generated based on the changing trends of the updated magnetic field strength deviation and oscillation frequency deviation. When the updated status level is in the danger zone, an upgraded protection action command is generated, and a signal source shutdown command and a bias power supply cut-off command are output.

[0017] This invention provides a radio frequency (RF) status detection circuit and method based on a diamond NV color center sensor. First, in response to an initial calibration command, a calibration fluorescence sequence is acquired and fitted to obtain a reference magnetic field strength and a reference oscillation frequency. Then, based on a preset acquisition period, a first fluorescence sequence is acquired in real time, and a first magnetic field strength and a first oscillation frequency are calculated. The absolute deviations of the first magnetic field strength from the reference magnetic field strength and the absolute deviations of the first oscillation frequency from the reference oscillation frequency are then calculated. The obtained deviations are compared with a preset grading threshold group to determine the status level. Based on the status level, a protection action command is output and executed. The updated status level is then acquired, and a protection action adjustment command is generated accordingly. This invention achieves accurate perception of the RF circuit status through non-contact magnetic field detection, realizing full-process control from anomaly identification to adaptive protection without affecting the original circuit matching performance. Attached Figure Description

[0018] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly described below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope.

[0019] Figure 1 A schematic diagram of the crystal structure of diamond NV color centers is shown; Figure 2 A schematic diagram of the diamond NV color center energy level structure is shown; Figure 3 The diamond NV color center on the optical fiber is shown; Figure 4 The topology diagram of a radio frequency status detection circuit based on a diamond NV color center sensor according to the present invention is shown. Figure 5 A flowchart of a radio frequency status detection method based on a diamond NV color center sensor according to the present invention is shown. Detailed Implementation

[0020] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] Unless otherwise defined, all terms (including technical and scientific terms) used in embodiments of this invention shall have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. It should also be understood that terms such as those defined in a common dictionary shall be interpreted as having a meaning consistent with their meaning in the context of the relevant art, and not as being interpreted in an idealized or highly formalized sense, unless expressly defined in this embodiment of the invention.

[0022] The terms "first," "second," and similar words used in the embodiments of this invention do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as "an," "a," or "the" do not indicate a quantity limitation, but rather indicate the presence of at least one. Similarly, terms such as "including" or "comprising" mean that the element or object preceding the word encompasses the elements or objects listed after the word and their equivalents, without excluding other elements or objects. Terms such as "connected" or "linked" are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. The steps preceding or following the steps in the method of the embodiments of this invention are not necessarily performed precisely in sequence. Instead, various steps can be processed in reverse order or simultaneously. Furthermore, other operations can be added to these processes, or one or more steps can be removed from these processes.

[0023] Diamond NV centers are a special type of luminescent defect in diamond crystals. Their formation can be achieved chemically, specifically by replacing a carbon atom in a diamond carbon bond with a nitrogen atom, creating a vacancy around the adjacent carbon atom. This process results in a vacancy around the nitrogen atom containing four inner-shell electrons and two outer-shell electrons, such as... Figure 1 As shown, this constitutes the structure of the diamond NV color center.

[0024] When a diamond NV color center is irradiated by a laser of a specific wavelength, the fluorescence emission process can be divided into the following steps: Excitation process: The applied excitation laser has a specific wavelength, such as 532 nm or 637 nm. These lasers can excite electrons in the diamond NV center, causing them to transition from the ground state to the excited state. Under 532 nm excitation, electrons in the diamond NV center transition from the ground state to the excited state, forming an excited-state diamond NV center.

[0025] Fluorescence emission: In the excited state of the diamond NV center, electrons return to the ground state after a period of time. This process is accompanied by fluorescence emission. The wavelength of fluorescence emission is typically concentrated in the range of 600 to 850 nm, exhibiting a red or near-infrared color. This optical property can be used to read out the NV spin state.

[0026] like Figure 2 As shown, Figure 2 The NV level structure includes the ground and excited states of triplet and singlet states, taking into account phonon effects. The two singlet states of the ground and excited states are merged into a metastable state. The upper right shows the fluorescence spectrum of the diamond NV color center, with the zero phonon line at 637 nm. The emitted fluorescence exhibits a Stokes shift, with the main wavelengths concentrated in the 600-850 nm range.

[0027] When microwaves are applied to the electron spin centers (NVs), resonance occurs when the microwave frequency matches the energy level difference of the NV electron spin transitions. The resonant microwaves cause the NVs to transition from the |0> state to the |+1> or |-1> state, resulting in a decrease in fluorescence count. This is known as electron spin resonance (ESR) of the NV color center. Unlike traditional ESR, because NV fluorescence is spin-dependent, the NV electron paramagnetic resonance signal can be detected by laser, i.e., optically detected magnetic resonance (ODMR). The resonance spectrum obtained by applying continuous laser and microwave is called CW-ODMR, or simply CW spectrum. In CW spectrum experiments, the laser causes the NV spins to tend to align in the |0> state, while the resonant microwaves cause the NV spins to move away from the |0> state. Therefore, the contrast of the continuous resonance peaks depends on the competition between laser power and microwave power, and the contrast can reach 30%.

[0028] Without an external magnetic field, the energy levels of the |+1> and |-1> states are degenerate, and the CW spectrum shows a resonance peak at 2870 MHz. With a weak magnetic field, the energy levels degenerate, and the CW spectrum shows two resonance peaks with a center of symmetry at 2870 MHz, corresponding to transitions from the |0> to |-1> and |0> to |+1> states, respectively. When the external magnetic field changes, the NV energy levels undergo a Zeeman shift, and the position of the CW spectrum resonance peak also shifts accordingly. When the external magnetic field is weak (e.g., <5 mT), the energy level shift caused by the transverse magnetic field is negligible; however, when the vertical magnetic field is greater than a preset value, the vertical term can also cause energy level shifts. Furthermore, the vertical magnetic field can cause energy level "mixing," affecting the NV luminescence process and thus reducing the NV fluorescence count.

[0029] Example 1:

[0030] This invention discloses a radio frequency state detection circuit based on a diamond NV color center sensor, such as... Figure 4As shown, the circuit includes: The signal processing unit 401, as the core control and operation center of the entire circuit, is implemented using a field-programmable gate array (FPGA) or a digital signal processor (DSP). It is used to receive and analyze the fluorescent digital signal after analog-to-digital conversion, and output protection instruction code after performing operations such as Lorentz fitting, Rabi oscillation calculation, and threshold comparison.

[0031] The laser driving unit 402 is used to receive the laser control signal from the signal processing unit, and output a constant current or modulated current to drive the laser to generate a laser beam with a wavelength suitable for exciting the diamond NV color center probe, which is then irradiated onto the diamond NV color center probe arranged at the node under test in the radio frequency circuit; wherein, the laser control signal includes setting the laser intensity and irradiation time.

[0032] The microwave signal generating unit 404 is used to receive the microwave control signal sent by the signal processing unit and generate a microwave signal to excite the spin transition of electrons in the diamond NV color center. The microwave signal is applied to the diamond NV color center probe through a microwave antenna or a near-field microstrip structure. The microwave control signal includes setting the microwave intensity and the microwave generation time.

[0033] The photoelectric conversion and signal conditioning unit 403 is used to collect the fluorescence intensity emitted by the diamond NV color center after being subjected to the combined action of laser and microwave. The optical signal is sequentially converted into a current analog signal, a voltage analog signal, and finally converted into a digital signal before being transmitted to the signal processing unit for analysis.

[0034] The protection execution interface unit 405 receives the protection command code issued by the signal processing unit, converts it into the corresponding physical control signal, and outputs it to the control terminal of the radio frequency circuit.

[0035] The circuit structure described above enables excitation control of the diamond NV color center probe, full-link acquisition and processing of fluorescence signals, and reliable output of protection commands, providing complete hardware support for non-contact monitoring and graded protection of RF circuit status.

[0036] In some possible implementations, the laser driving unit consists of a precision constant current source circuit. Its input is connected to the general-purpose input / output interface or digital-to-analog converter interface of the signal processing unit, receiving laser control signals from the signal processing unit. These control signals include laser on / off commands and output power settings. Based on the received control signals, the laser driving unit outputs a constant current or modulated current to drive the laser, ensuring that the laser stably outputs excitation light of a preset wavelength within the acquisition period. The laser is selected as a solid-state laser or semiconductor laser with an output wavelength of 532 nm. This wavelength can effectively excite the diamond nitrogen-vacancy centers, causing them to transition from the ground state to the excited state, generating fluorescence radiation that can be used for spin readout.

[0037] In some possible implementations, the microwave signal generation unit consists of a phase-locked loop frequency synthesizer, a voltage-controlled oscillator, a variable attenuator, and a microwave switch. Its input is connected to the serial or parallel interface of the signal processing unit to receive microwave control signals from the signal processing unit. These microwave control signals include operating mode selection, frequency setting, output power setting, and microwave pulse timing parameters. The microwave signal generation unit supports two operating modes: a swept-frequency mode and a fixed-frequency mode. The swept-frequency mode is used for optically detected magnetic resonance spectral acquisition. By stepping the output frequency and maintaining a fixed time at each frequency point, the corresponding fluorescence intensity is acquired in conjunction with the signal processing unit, thereby obtaining the complete resonance spectrum and extracting the center frequency of the resonance peak. The fixed-frequency mode is used for Rabi oscillation measurement. Microwave pulses of different durations are output at the center frequency of the resonance peak. By acquiring the fluorescence intensity changes corresponding to the duration of each pulse, the Rabi oscillation curve is fitted, and the magnetic field strength is inverted.

[0038] Example 2:

[0039] In another embodiment of the present invention, the photoelectric conversion and signal conditioning unit specifically includes a photomultiplier tube, a transconductance amplifier, a programmable gain amplifier, a filter, and an analog-to-digital converter.

[0040] Among them, the photomultiplier tube converts the light intensity signal of the diamond NV color center into a current analog signal; the transconductance amplifier converts the current analog signal into a voltage analog signal; the programmable gain amplifier is used to adjust the range of acceptable fluorescence light intensity; the filter is used to filter noise at a set frequency of the voltage analog signal; and the analog-to-digital converter converts the voltage analog signal into a digital signal.

[0041] In this embodiment, a photomultiplier tube (PMT) serves as the front-end sensor, positioned in the fluorescence emission path of the diamond NV color center probe. It receives the fluorescence intensity emitted by the probe and converts it into a weak analog current signal. The PMT's high gain enables it to detect extremely weak light signals. A transconductance amplifier is connected to the PMT's output, converting the PMT's analog current signal into an analog voltage signal and performing primary amplification. A programmable gain amplifier (PGA) is connected to the PMT's output; its gain is dynamically configured by the signal processing unit via a control interface. This PPA adjusts the signal amplitude based on the real-time fluorescence signal intensity to match the analog-to-digital converter's (ADC) input range. A filter is connected to the PPA's output to remove noise components outside the set frequency range from the analog voltage signal, improving the signal-to-noise ratio. The ADC converts the filtered analog voltage signal into a digital signal, which is then transmitted via a data bus to the signal processing unit for further processing.

[0042] Example 3:

[0043] This invention discloses a radio frequency state detection method based on a diamond NV color center sensor, such as... Figure 5 As shown, the detection method specifically includes: Step S502: In response to the initial calibration command, acquire the calibration fluorescence sequence; In this step, the signal processing unit responds to the initial calibration command triggered during host computer or system initialization, controlling the laser drive unit and microwave signal generation unit to work together. The diamond NV color center probe, located at the node under test in the RF circuit, is excited, and the fluorescence signal generated by the probe under the combined action of laser and microwave is acquired through the photoelectric conversion and signal conditioning unit, forming a calibration fluorescence sequence. Here, the fluorescence signal is a digital signal converted from fluorescence intensity, and the fluorescence sequence is a sequence composed of multiple fluorescence signals; the calibration fluorescence sequence is the fluorescence sequence in the calibration phase.

[0044] Step S504: After Lorentz fitting the calibration fluorescence sequence, the reference magnetic field strength and reference oscillation frequency are extracted. In this step, the signal processing unit performs Lorentz fitting on the calibration fluorescence sequence to extract the reference magnetic field strength and reference oscillation frequency characterizing the node under normal operating conditions, and stores them as a reference baseline for subsequent judgment.

[0045] In some possible implementations, in response to the initial calibration command, the laser driving unit first controls the laser to output excitation light at a preset power, continuously irradiating the diamond NV color center probe to put it in an optically excited state. Simultaneously, the microwave signal generation unit controls the microwave frequency to output in a stepwise manner within a preset frequency sweep range. At each sweep point, the photoelectric conversion and signal conditioning unit collects the fluorescence signal intensity generated by the probe, forming a first calibration fluorescence sequence. The signal processing unit performs Lorentz fitting on this sequence to accurately extract the center frequency of the resonance peak in the ODMR spectrum, using it as the reference oscillation frequency. Subsequently, the signal processing unit controls the microwave signal generation unit to output this reference oscillation frequency at a fixed time and switches to pulsed microwave mode, applying microwave pulses of different durations to the diamond NV color center probe. At each microwave pulse application time point, the corresponding fluorescence signal intensity is collected, forming a second calibration fluorescence sequence. The signal processing unit performs Rabi oscillation curve fitting on this sequence and calculates the reference magnetic field strength directly related to the microwave magnetic field strength from the oscillation curve.

[0046] It should be noted that the Lorentz fitting formula is: ;in, The fluorescence signal intensity, The maximum fluorescence signal intensity for each resonance peak, The frequency of the microwave pulse. Center scan frequency, The width and height are one-quarter. The frequency corresponding to the resonance peak with the best signal-to-noise ratio among the eight resonance peaks of the ODMR (Optically Probemed Magnetic Resonance) curve is selected and scanned to obtain the Rabi oscillation curve.

[0047] Rabi oscillation curves are used to represent the intensity of fluorescence signals. Time of microwave action on diamond NV color centers The relationship is given, and the following formula is applied for fitting: ;in, The angular frequency of the Rabi oscillation. The amplitude of the Rabi oscillation. The intensity of the ground-state fluorescence signal in the NV color center ground state. This represents the Rabi oscillation decay time.

[0048] In addition, the Rabi oscillation angular frequency and the microwave magnetic field component perpendicular to the NV axis direction The relationship can be represented as: ;in, It is the gyromagnetic ratio.

[0049] Combining the above formulas, we can obtain that ; In other words, by performing Rabi oscillation detection on the NV color center of diamond, the intensity of the microwave magnetic field at a certain point can be estimated from the intensity of the fluorescence signal.

[0050] Step S506: Based on the preset acquisition cycle, excite the diamond NV color center probe to acquire the first fluorescence sequence in real time; In this step, the system enters real-time monitoring mode. The signal processing unit periodically controls the laser and microwave signal source to excite the diamond NV color center probe according to the preset acquisition cycle, and acquires the first fluorescence sequence in real time. Here, the fluorescence signal is a digital signal converted from fluorescence intensity, and the fluorescence sequence is a sequence composed of multiple fluorescence signals; the first fluorescence sequence is the real-time fluorescence sequence in the detection stage.

[0051] Step S508: Based on the first fluorescence sequence, calculate the first magnetic field strength and the first oscillation frequency; In this step, the first magnetic field strength and the first oscillation frequency at the current moment are calculated based on the first fluorescence sequence.

[0052] In some possible implementations, based on a preset acquisition cycle, at the beginning of each cycle, the laser driving unit first controls the laser to excite the diamond NV color center probe. Simultaneously, the microwave signal generation unit controls a narrow-band frequency sweep centered on a reference oscillation frequency, performing step-scanning only within a narrow frequency range near this center frequency, acquiring the fluorescence signal intensity corresponding to each sweep point to form a first real-time fluorescence sequence. The signal processing unit performs Lorentz fitting on this sequence, quickly extracting the center frequency of the real-time resonance peak, which is used as the first oscillation frequency at the current moment. This frequency shift reflects changes in the external magnetic field environment or circuit state. Subsequently, the microwave signal generation unit is controlled to maintain a fixed output of this first oscillation frequency and switches to pulsed microwave mode, applying microwave pulses of different durations to the diamond NV color center probe, acquiring the fluorescence signal intensity corresponding to each pulse duration to form a second real-time fluorescence sequence. The second real-time fluorescence sequence is then fitted with a Rabi oscillation curve, and the first magnetic field strength at the current moment is calculated from the fitting result.

[0053] Step S510: Calculate the absolute deviation between the first magnetic field strength and the reference magnetic field strength to obtain the magnetic field strength deviation; Step S512: Calculate the absolute deviation between the first oscillation frequency and the reference oscillation frequency to obtain the oscillation frequency deviation; In steps S510 and S512, the signal processing unit calculates the absolute deviation between the first magnetic field strength and the reference magnetic field strength, and the absolute deviation between the first oscillation frequency and the reference oscillation frequency, respectively, to obtain the magnetic field strength deviation and the oscillation frequency deviation.

[0054] Step S514: Based on the magnetic field strength deviation and oscillation frequency deviation, compare them with the preset grading threshold group to obtain the state level. In this step, the signal processing unit compares the two deviations with a preset grading threshold group to determine the current state level of the radio frequency circuit.

[0055] In some possible implementations, the hierarchical threshold group includes at least a first magnetic field threshold. Second magnetic field threshold First frequency threshold With the second frequency threshold Four parameters are used, where the first magnetic field threshold and the first frequency threshold define the allowable fluctuation range under normal conditions, while the second magnetic field threshold and the second frequency threshold define the critical boundaries of dangerous conditions. The calculated magnetic field strength deviation is then used... and oscillation frequency deviation Compared with the graded threshold group: like and If the status level is determined to be in the normal zone, no protection action needs to be triggered, and the system records the data and waits for the next sampling cycle. like or If the condition is met, the status level is determined to be a warning zone. At this time, the system records the trigger threshold type (magnetic field over-limit or frequency over-limit) and prepares to output a minor protection action; like or If the status level is determined to be dangerous, the system will prepare to output a heavy protection action.

[0056] Step S516: After outputting and executing the protection action command according to the status level, obtain the updated status level; In this step, based on the determined state level, the signal processing unit outputs and executes the corresponding protection action command through the protection execution interface unit, and continues to obtain the updated state level for the next sampling period after executing the protection action.

[0057] In some possible implementations, when the signal processing unit determines that the current state level is a warning zone, it first calculates the ratio of the magnetic field strength deviation to the second magnetic field threshold and the ratio of the oscillation frequency deviation to the second frequency threshold, and uses the larger of the two as a quantitative indicator to measure the severity of the anomaly. Subsequently, based on the magnitude of this quantitative indicator, the signal processing unit generates a corresponding power reduction request command or matching network adjustment command, and sends it to the control terminal of the RF circuit in the form of analog voltage or digital commands through the protection execution interface unit, achieving fine-grained adjustment of the RF circuit's operating state. When the signal processing unit determines that the current state level is a danger zone, it directly outputs a signal source shutdown command and a bias power supply cut-off command, and sends them to the protection control node of the RF circuit in a hardware latching manner through the protection execution interface unit, ensuring that even if the subsequent signal processing unit cannot update the output due to interference or fault, the protection state can still be maintained, and the RF circuit remains in a safe state. Through the differentiated design of the warning zone intensity-level output and the danger zone hardware latching output, a graded response to the abnormal state of the RF circuit from mild to severe is achieved, avoiding system interruptions caused by premature shutdown and ensuring reliable execution of protection actions in the event of severe anomalies.

[0058] Step S518: Generate protection action adjustment instructions based on the updated status level.

[0059] In this step, protection action adjustment commands are generated based on the updated status level, realizing closed-loop control of monitoring, judgment, execution, and adjustment. This embodiment achieves non-contact real-time monitoring and graded response of the circuit's operating status without changing the original matching state of the RF circuit.

[0060] In some possible implementations, after outputting and executing the protection action command, the signal processing unit continues to acquire the updated status level according to a preset acquisition cycle, and executes a differentiated adjustment strategy based on the updated status level. When the updated status level is in the normal zone, the signal processing unit continuously monitors and counts the number of consecutive normal states. Only when the number of consecutive normal states reaches a preset threshold is it determined that the RF circuit has stably recovered to normal, and then a protection action cancellation command is generated to stop the previous protection intervention and restore the circuit to normal operation mode. When the updated status level is still in the warning zone, the signal processing unit further analyzes the changing trends of the updated magnetic field strength deviation and oscillation frequency deviation compared to the previous ones. If the deviation shows a decreasing trend, a command to maintain the current protection action is generated; if the deviation shows an increasing trend or no improvement, a command to increase the protection strength is generated. When the updated status level is in the danger zone, the signal processing unit immediately generates an upgraded protection action command, outputs a signal source shutdown command and a bias power supply cut-off command, and executes an emergency shutdown. Through the above closed-loop adjustment mechanism based on the state change trend and continuity, adaptive optimization of the protection action is achieved.

[0061] It is worth mentioning that, in some possible implementations, after generating the protection action adjustment command, the following is further included: Acquire the status level sequence and corresponding protection action records during the execution and adjustment of protection action commands; Based on the state level sequence and protection action records, generate state change trajectory data; The status change trajectory data is reported to the host computer through the communication interface unit; In response to the optimization configuration command issued by the host computer, update the threshold parameters in the hierarchical threshold group, or update the mapping strategy of the protection action command.

[0062] It should be noted that in this embodiment, during each execution of a protection action command and subsequent adjustment command, the historical state level sequence and corresponding protection action record are continuously recorded, including the timestamp of each state level determination, the specific deviation value, the type of protection action executed, and the state change after the protection action. During system operation or in response to a request command from the host computer, the signal processing unit generates state change trajectory data based on the recorded historical state level sequence and protection action record. This trajectory data fully reflects the entire process of the radio frequency circuit from the occurrence of a state anomaly, the intervention of protection action, to state recovery or deterioration. Subsequently, the signal processing unit reports the state change trajectory data to the host computer through the communication interface unit for maintenance personnel or automated analysis systems to perform fault analysis and system evaluation. More importantly, in response to the optimization configuration command issued by the host computer, the signal processing unit dynamically updates the threshold parameters of the graded threshold group or updates the mapping strategy of the protection action command, realizing continuous updating of system parameters. Through the above-mentioned historical data recording and strategy optimization mechanism, monitoring and protection performance can be continuously optimized in practical applications.

[0063] Example 4:

[0064] In some possible implementations, prior to acquiring the calibration fluorescence sequence, the following further steps are included: Based on the topology of the radio frequency circuit under test, multiple preset monitoring nodes are determined, and diamond NV color center probes are arranged at each preset monitoring node. In response to the multi-channel calibration command, the laser and microwave signal generation units corresponding to each preset monitoring node are controlled sequentially to collect the calibration fluorescence sequence at each node. Based on the calibration fluorescence sequence at each node, the reference magnetic field strength and reference oscillation frequency corresponding to each node are obtained by fitting, and the mapping relationship between the node and the reference data is established. When acquiring the first fluorescence sequence in real time: the diamond NV color center probes at each preset monitoring node are excited sequentially, and the first fluorescence sequence corresponding to each node is acquired in real time; based on the first fluorescence sequence corresponding to each node, the first magnetic field strength and the first oscillation frequency corresponding to each node are calculated respectively.

[0065] In this embodiment, applied to a multi-node monitoring scenario, several key nodes requiring focused monitoring are first identified based on the topology of the RF circuit under test. These include locations such as the drain of the power amplifier transistor, key points on transmission lines, and antenna feed points. Diamond NV color center probes are then deployed at each preset monitoring node, each equipped with an independent laser, microwave antenna, and photoelectric acquisition channel. Responding to multi-channel calibration commands, the signal processing unit sequentially controls the laser and microwave signal source corresponding to each monitoring node according to a preset channel order. It acquires calibration fluorescence sequences at each node and fits the corresponding reference magnetic field strength and reference oscillation frequency based on each sequence, establishing a mapping relationship between node identifiers and reference data. Upon entering real-time monitoring mode, the signal processing unit sequentially excites the diamond NV color center probes at each preset monitoring node according to a preset acquisition cycle, acquiring the first fluorescence sequence corresponding to each node in real time. Based on the first fluorescence sequence, it calculates the first magnetic field strength and first oscillation frequency for each node, and then performs deviation calculations and status level determination for each node. Through this multi-node synchronous monitoring implementation, comprehensive detection of the status of multiple points on the RF circuit is achieved.

[0066] Example 5:

[0067] In some possible implementations, before comparing the magnetic field strength deviation and oscillation frequency deviation with the grading threshold, further include: The ambient temperature value is obtained through an ambient temperature sensor; Based on the ambient temperature value, the preset temperature compensation mapping table is consulted to obtain the temperature compensation coefficient; Based on the temperature compensation coefficient, temperature compensation corrections are made for the reference magnetic field strength, reference oscillation frequency, first magnetic field strength, and first oscillation frequency, respectively. Based on the compensated and corrected reference magnetic field strength, reference oscillation frequency, first magnetic field strength, and first oscillation frequency, the magnetic field strength deviation and oscillation frequency deviation are recalculated.

[0068] In this embodiment, before performing deviation calculation, the signal processing unit first obtains the current ambient temperature value through a temperature sensor, and then queries a temperature compensation mapping table based on this temperature value. The mapping table, obtained through experimental calibration, records the drift compensation coefficients for magnetic field strength and oscillation frequency under different ambient temperatures. Based on the obtained temperature compensation coefficients, the signal processing unit performs temperature compensation corrections on the reference magnetic field strength, reference oscillation frequency, first magnetic field strength, and first oscillation frequency. Specifically, the correction method involves calculating the parameter values ​​with the corresponding compensation coefficients to eliminate the influence of temperature changes on the diamond NV color center energy level structure and optical readout process. By introducing a temperature compensation mechanism, this embodiment effectively suppresses the impact of ambient temperature changes on the accuracy of magnetic field measurement, improving the stability and reliability of condition monitoring under different working environments.

[0069] In summary, this invention provides a radio frequency (RF) status detection circuit and method based on a diamond NV color center sensor. First, in response to an initial calibration command, a calibration fluorescence sequence is acquired and fitted to obtain a reference magnetic field strength and a reference oscillation frequency. Then, based on a preset acquisition period, a first fluorescence sequence is acquired in real time, and the first magnetic field strength and the first oscillation frequency are calculated. The absolute deviations of the first magnetic field strength from the reference magnetic field strength and the absolute deviations of the first oscillation frequency from the reference oscillation frequency are then calculated. The obtained deviations are compared with a preset grading threshold group to determine the status level. Based on the status level, a protection action command is output and executed, and then the updated status level is acquired to generate a protection action adjustment command. This invention achieves accurate perception of the RF circuit status through non-contact magnetic field detection, realizing full-process control from anomaly identification to adaptive protection without affecting the original circuit matching performance.

[0070] In addition, the functional modules in the various embodiments of the present invention can be integrated together to form an independent part, or each module can exist independently, or two or more modules can be integrated to form an independent part.

[0071] If the aforementioned functions are implemented as software functional modules and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this invention, or the part that contributes to the prior art, or a portion of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods of the various embodiments of this invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0072] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A radio frequency state detection circuit based on a diamond NV color center sensor, characterized in that, The circuit includes: The signal processing unit is used to analyze the digital signal of fluorescence, and after performing fitting, oscillation calculation and threshold comparison operations, it outputs protection instruction code. The laser driving unit receives the laser control signal from the signal processing unit and drives the laser to generate excitation light of a preset wavelength to irradiate the diamond NV color center probe. The microwave signal generating unit receives the microwave control signal from the signal processing unit and uses it to generate a microwave signal that excites the diamond NV color center. The photoelectric conversion and signal conditioning unit is used to collect the fluorescence intensity of the diamond NV color center, convert the optical signal into a digital signal, and transmit it to the signal processing unit. The protection execution interface unit receives the protection instruction code from the signal processing unit and outputs the protection action instruction to the control terminal of the radio frequency circuit.

2. The radio frequency status detection circuit based on a diamond NV color center sensor according to claim 1, characterized in that, The laser driving unit further includes: Based on the laser control signal, a constant or modulated current is output to drive the laser; The laser wavelength of the laser is 532nm.

3. The radio frequency status detection circuit based on a diamond NV color center sensor according to claim 1, characterized in that, The microwave signal generating unit further includes: Sweep frequency working mode and fixed frequency working mode; The frequency sweeping mode is used for ODMR spectral acquisition to obtain the center frequency of the resonance peak; The fixed-frequency operating mode is used for Rabi oscillation measurement to obtain the magnetic field strength.

4. The radio frequency status detection circuit based on a diamond NV color center sensor according to claim 1, characterized in that, The photoelectric conversion and signal conditioning unit specifically includes: Photomultiplier tubes, transconductance amplifiers, programmable gain amplifiers, filters, and analog-to-digital converters; The photomultiplier tube converts the light intensity signal of the diamond NV color center into an analog current signal. The transconductance amplifier converts the current analog signal into a voltage analog signal; The programmable gain amplifier is used to adjust the range of acceptable fluorescence intensity. The filter is used to filter noise at a set frequency from the voltage analog signal; The analog-to-digital converter converts the voltage analog signal into a digital signal.

5. A radio frequency (RF) status detection method based on a diamond NV color center sensor, applied in the RF status detection circuit based on a diamond NV color center sensor as described in any one of claims 1-4, characterized in that, The method includes: In response to the initial calibration command, a calibration fluorescence sequence is acquired; After Lorentz fitting the calibration fluorescence sequence, the reference magnetic field strength and reference oscillation frequency were extracted. Based on a preset acquisition cycle, the diamond NV color center probe is excited to acquire the first fluorescence sequence in real time. Based on the first fluorescence sequence, the first magnetic field strength and the first oscillation frequency are calculated. Calculate the absolute deviation between the first magnetic field strength and the reference magnetic field strength to obtain the magnetic field strength deviation; Calculate the absolute deviation between the first oscillation frequency and the reference oscillation frequency to obtain the oscillation frequency deviation; The state level is obtained by comparing the magnetic field strength deviation and the oscillation frequency deviation with a preset grading threshold group. Based on the stated status level, after outputting and executing the protection action command, the updated status level is obtained; Based on the updated status level, a protection action adjustment instruction is generated.

6. The radio frequency state detection method based on a diamond NV color center sensor according to claim 5, characterized in that, The process of extracting the reference magnetic field strength and reference oscillation frequency after Lorentz fitting of the calibration fluorescence sequence specifically includes: In response to the initial calibration command, the laser is controlled to excite the diamond NV color center probe; The microwave signal generating unit is controlled to perform frequency sweep within a preset frequency sweep range, and the fluorescence signal corresponding to each frequency sweep point is collected to obtain the first calibration fluorescence sequence. The first calibration fluorescence sequence was Lorentz-fitted, and the center frequency of the resonance peak was extracted as the reference oscillation frequency. The microwave signal generating unit is fixed at the reference oscillation frequency and acts on the diamond NV color center probe in pulsed microwave mode. Fluorescence signals corresponding to different microwave action times are collected to obtain the second calibration fluorescence sequence. The reference magnetic field strength is calculated by fitting the Rabi oscillation curve based on the second calibration fluorescence sequence.

7. The radio frequency state detection method based on a diamond NV color center sensor according to claim 5, characterized in that, The step of calculating the first magnetic field strength and the first oscillation frequency based on the first fluorescence sequence specifically includes: Based on a preset acquisition cycle, the laser is controlled to excite the diamond NV color center probe; The microwave signal generating unit is controlled to perform a narrowband frequency sweep in the neighborhood of the reference oscillation frequency, and the fluorescence signal corresponding to each sweep point is collected to obtain the first real-time fluorescence sequence. Based on the first real-time fluorescence sequence, Lorentz fitting is performed to extract the center frequency of the real-time resonance peak, which is used as the first oscillation frequency. The microwave signal generating unit is fixed at the first oscillation frequency and acts on the diamond NV color center probe in pulse microwave mode. Fluorescence signals corresponding to different microwave action times are collected to obtain the second real-time fluorescence sequence. The first magnetic field strength is calculated by fitting the Rabi oscillation curve based on the second real-time fluorescence sequence.

8. The radio frequency state detection method based on a diamond NV color center sensor according to claim 5, characterized in that, The process of comparing the magnetic field strength deviation and oscillation frequency deviation with a preset grading threshold group to obtain the state level specifically includes: The graded threshold group includes a first magnetic field threshold, a second magnetic field threshold, a first frequency threshold, and a second frequency threshold; When the magnetic field strength deviation is less than or equal to the first magnetic field threshold and the oscillation frequency deviation is less than or equal to the first frequency threshold, the state level is determined to be the normal zone. When the magnetic field strength deviation is greater than the first magnetic field threshold and less than or equal to the second magnetic field threshold, or when the oscillation frequency deviation is greater than the first frequency threshold and less than or equal to the second frequency threshold, the state level is determined to be a warning zone. When the magnetic field strength deviation is greater than the second magnetic field threshold, or the oscillation frequency deviation is greater than the second frequency threshold, the state level is determined to be a dangerous zone.

9. The radio frequency state detection method based on a diamond NV color center sensor according to claim 8, characterized in that, The step of outputting and executing protection action commands based on the status level specifically includes: When the state level is the warning zone, calculate the ratio of the magnetic field strength deviation to the second magnetic field threshold, and the ratio of the oscillation frequency deviation to the second frequency threshold. Based on the larger of the intensity ratio and the frequency ratio, a power reduction request command or a matching network adjustment command is output and sent to the control terminal of the radio frequency circuit through the protection execution interface unit; When the status level is the danger zone, the output signal source shutdown command and bias power supply cut-off command are sent to the protection control node of the radio frequency circuit through the protection execution interface unit in a hardware latching manner.

10. The radio frequency state detection method based on a diamond NV color center sensor according to claim 5, characterized in that, The step of generating protection action adjustment instructions based on the updated status level specifically includes: Update the obtained status level after receiving the protection action command; When the updated status level is in the normal zone and the number of consecutive normal occurrences reaches a preset threshold, a protection revocation action command is generated. When the updated status level is still in the warning zone, a command to maintain the current protection action or a command to increase the protection strength are generated based on the changing trends of the updated magnetic field strength deviation and oscillation frequency deviation. When the updated status level is in the danger zone, an upgraded protection action command is generated, and a signal source shutdown command and a bias power supply cut-off command are output.

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