A quadrupole rod radio frequency power amplifier circuit and quadrupole mass spectrometer

Abstract

The application discloses a quadrupole RF power amplifier circuit and a quadrupole mass spectrometer. The quadrupole RF power amplifier circuit comprises: an excitation signal input module, an input end of the excitation signal input module being used for connecting a RF excitation signal source; a high-voltage operational amplifier module, a non-inverting input end of the high-voltage operational amplifier module being connected with an output end of the excitation signal input module; a feedback adjustment module, an input end of the feedback adjustment module being connected with an output end of the high-voltage operational amplifier module, an output end of the feedback adjustment module being connected with an inverting input end of the high-voltage operational amplifier module, the feedback adjustment module being used for comparing an amplified RF excitation signal with a preset reference signal and generating a feedback signal transmitted to the high-voltage operational amplifier module, so as to adjust an amplification multiple of the high-voltage operational amplifier module; and a power output module, an input end of the power output module being connected with an output end of the high-voltage operational amplifier module, an output end of the power output module being used for connecting a quadrupole. Through the above manner, the application can improve the performance of the quadrupole RF power.

Description

Technical Field

[0001] This application relates to the field of quadrupole mass spectrometer technology, and in particular to a quadrupole radio frequency power amplifier circuit and a quadrupole mass spectrometer. Background Technology

[0002] In a quadrupole mass spectrometer, the radio frequency (RF) power supply is a core component. Its performance directly affects the quadrupole's efficiency in ion selection and transmission, thus determining the mass spectrometer's detection accuracy and sensitivity. The quadrupole requires a stable, high-precision RF signal to create a specific electric field, enabling the separation of ions with different mass-to-charge ratios.

[0003] Currently, most existing quadrupole RF power amplifier circuits are built using discrete components, such as high-power transistors and field-effect transistors. These circuits have the following drawbacks: First, their complex structure makes debugging difficult, hindering mass production; second, the linearity and stability of the output signal are poor, easily affected by environmental factors such as temperature and humidity, leading to instability in the quadrupole electric field and affecting ion screening results; third, their high distortion introduces noise into the RF signal, interfering with mass spectrometry detection results.

[0004] Furthermore, some amplifier circuits that utilize integrated operational amplifiers (op-amps) suffer from limitations in voltage withstand capability and output power, making it difficult to meet the demands of quadrupole amplifiers for high-voltage, high-power radio frequency (RF) signals. Therefore, developing an RF power amplifier circuit based on a high-voltage op-amp that can output stable signals and meet the requirements of quadrupole amplifiers is of great significance. Utility Model Content

[0005] This application mainly provides a quadrupole RF power supply amplifier circuit and a quadrupole mass spectrometer to solve the problem of poor performance of quadrupole RF power supplies.

[0006] To solve the above-mentioned technical problems, one technical solution adopted in this application is: providing a quadrupole RF power amplifier circuit, the quadrupole RF power amplifier circuit comprising: an excitation signal input module, the input terminal of which is connected to an RF excitation signal source to receive the input RF excitation signal and preprocess the RF excitation signal; a high-voltage operational amplifier module, the non-inverting input terminal of which is connected to the output terminal of the excitation signal input module to amplify the RF excitation signal; a feedback adjustment module, the input terminal of which is connected to the output terminal of the high-voltage operational amplifier module, and the output terminal of which is connected to the inverting input terminal of the high-voltage operational amplifier module to compare the amplified RF excitation signal with a preset reference signal and generate a feedback signal transmitted to the high-voltage operational amplifier module to adjust the amplification factor of the high-voltage operational amplifier module; and a power output module, the input terminal of which is connected to the output terminal of the high-voltage operational amplifier module, and the output terminal of which is connected to the quadrupole, the power output module amplifying the amplified RF excitation signal to output power matching the quadrupole.

[0007] In some embodiments, the high-voltage operational amplifier module is built based on a high-voltage operational amplifier chip, the output voltage range of which is 100-1000V.

[0008] In some embodiments, the excitation signal input module includes a signal attenuator, a bandpass filter, and an impedance matching device; the input terminal of the signal attenuator is connected to the radio frequency excitation signal source, the output terminal of the signal attenuator is connected to the input terminal of the bandpass filter, and the output terminal of the bandpass filter is connected to the non-inverting input terminal of the high-voltage operational amplifier module.

[0009] In some embodiments, the signal attenuator is provided with a resistor voltage divider circuit; the bandpass filter is an LC bandpass filter, and the center frequency of the LC bandpass filter is consistent with the frequency of the RF signal provided by the RF excitation signal source; the impedance matching device is provided with a transformer-type matching circuit.

[0010] In some embodiments, the feedback adjustment module includes a sampling circuit, a comparator, and an error amplifier; the input terminal of the sampling circuit is connected to the output terminal of the high-voltage operational amplifier module, the output terminal of the sampling circuit is connected to the first input terminal of the comparator, the second input terminal of the comparator is connected to a reference signal source, the output terminal of the comparator is connected to the input terminal of the error amplifier, and the output terminal of the error amplifier is connected to the inverting input terminal of the high-voltage operational amplifier module.

[0011] In some embodiments, the sampling circuit includes a resistor voltage divider sampling circuit with a sampling ratio ranging from 1 / 60 to 1 / 200; the comparator has an accuracy of no more than 3mV; and the error amplifier is an operational amplifier with a gain of 10.

[0012] In some embodiments, the power output module includes a power driver stage and an output matching network; the input terminal of the power driver stage is connected to the output terminal of the high-voltage operational amplifier module, the input terminal of the power driver stage is connected to the input terminal of the output matching network, and the output terminal of the output matching network is connected to the quadrupole.

[0013] In some embodiments, the power driver stage is provided with a transistor with a power of no more than 20W, and the output matching network is provided with a π-type LC matching circuit.

[0014] In some embodiments, the quadrupole RF power amplifier circuit further includes a power supply module; the input terminal of the power supply module is connected to the mains power supply, and the output terminal of the power supply module is respectively connected to the power supply terminal of the excitation signal input module, the power supply terminal of the high voltage operational amplifier module, the power supply terminal of the feedback adjustment module, and the power output module; the output terminal of the power supply module is also connected to the quadrupole.

[0015] To solve the above-mentioned technical problems, another technical solution adopted in this application is: to provide a quadrupole mass spectrometer, including a quadrupole and a quadrupole RF power amplifier circuit as described above. The RF power amplifier circuit obtains the RF excitation signal through the excitation signal input module, and then connects to the quadrupole of the quadrupole mass spectrometer through the power output module to provide the quadrupole with the processed RF signal.

[0016] The beneficial effects of this application are as follows: Unlike existing technologies, this application discloses a quadrupole RF power amplifier circuit and a quadrupole mass spectrometer. The quadrupole RF power amplifier circuit includes an excitation signal input module. The input terminal of the excitation signal input module is connected to an RF excitation signal source to receive the input RF excitation signal and preprocess it. The external RF signal, after preprocessing by the excitation signal input module, enters a high-voltage operational amplifier module for amplification. The high-voltage operational amplifier module has its non-inverting input terminal connected to the output terminal of the excitation signal input module for amplifying the RF excitation signal. The use of a high-performance high-voltage operational amplifier module ensures good linearity, low output signal distortion, and reduces interference from noise on the mass spectrometry detection results. The feedback adjustment module connects its input to the output of the high-voltage operational amplifier (HVA) module and its output to the inverting input of the HVA module. It compares the amplified RF excitation signal with a preset reference signal and generates a feedback signal to be transmitted to the HVA module, thereby adjusting the amplification factor. The power output module connects its input to the output of the HVA module and its output to a quadrupole. The power output module amplifies the amplified RF excitation signal to provide a power output matching the quadrupole. The output of the power output module is connected to the quadrupole, and the amplified signal is transmitted to the quadrupole after power enhancement. Simultaneously, the feedback adjustment module monitors the output signal of the HVA module in real time, adjusting it to ensure the stability of the output RF signal, reduce the impact of environmental factors, and enable the quadrupole to form a stable electric field, improving the accuracy of ion screening. The power output module provides a high-voltage, high-power RF signal to the quadrupole, meeting its operational requirements. Through the above methods, the frequency of the output RF signal of the quadrupole RF power amplifier circuit provided in this application is stabilized at 1-3MHz, the peak-to-peak amplitude can reach 3000V, the linearity error is less than 0.5%, and the distortion is less than 0.1%, which can well meet the working requirements of the quadrupole and effectively improve the detection performance of the quadrupole mass spectrometer. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort, wherein: Figure 1 This is a schematic diagram of an embodiment of the quadrupole RF power amplifier circuit provided in this application; Figure 2Is it like this? Figure 1 The diagram shows a structural schematic of an embodiment of the circuit excitation signal input module. Figure 3 Is it like this? Figure 1 The diagram shows a structural schematic of one embodiment of the circuit feedback adjustment input module. Figure 4 Is it like this? Figure 1 The diagram shown is a structural schematic of one embodiment of the power output / input module of the circuit. Figure 5 Is it like this? Figure 1 A schematic diagram of another embodiment of the circuit shown. Detailed Implementation

[0018] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0019] The terms "first," "second," and "third" used in the embodiments of this application are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first," "second," or "third" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or device that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to these processes, methods, products, or devices.

[0020] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a mutually exclusive, independent, or alternative embodiment. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0021] See Figure 1 , Figure 1 This is a schematic diagram of an embodiment of the quadrupole RF power amplifier circuit provided in this application. The quadrupole RF power amplifier circuit 100 includes: The excitation signal input module 10 has its input terminal connected to a radio frequency excitation signal source to receive the input radio frequency excitation signal and preprocess the radio frequency excitation signal.

[0022] The external radio frequency excitation signal is processed by the excitation signal input module 10, which attenuates the strong signal to a safe range, filters out harmonics and spurious interference, outputs a clean signal, and matches the input impedance of the high-voltage operational amplifier module 20 to reduce signal reflection.

[0023] The high-voltage operational amplifier module 20 has its non-inverting input connected to the output of the excitation signal input module 10, and is used to amplify the radio frequency excitation signal.

[0024] The high-voltage operational amplifier module 20 has high voltage withstand capability. The pre-processed signal enters the non-inverting input terminal of the high-voltage operational amplifier module 20, where the high-voltage operational amplifier module 20 performs core amplification of the signal and outputs a pre-amplified radio frequency signal.

[0025] The feedback adjustment module 30 has its input terminal connected to the output terminal of the high-voltage operational amplifier module 20 and its output terminal connected to the inverting input terminal of the high-voltage operational amplifier module 20. It is used to compare the amplified radio frequency excitation signal with a preset reference signal and generate a feedback signal transmitted to the high-voltage operational amplifier module 20 to adjust the amplification factor of the high-voltage operational amplifier module 20.

[0026] The feedback adjustment module 30 acquires the output signal of the high-voltage operational amplifier module 20, generates a feedback signal based on the RF signal output by the high-voltage operational amplifier module 20, inputs it to the inverting input terminal of the high-voltage operational amplifier module 20, and dynamically adjusts its amplification factor to ensure the stability of the output signal.

[0027] The power output module 40 has its input terminal connected to the output terminal of the high-voltage operational amplifier module 20, and its output terminal connected to a quadrupole. The power output module 40 amplifies the amplified radio frequency excitation signal to output power that matches the quadrupole.

[0028] The signal output by the high-voltage operational amplifier module 20 is further processed by the power output module 40 to increase the signal power and match the quadrupole input impedance, ensuring that the radio frequency signal is transmitted to the quadrupole at maximum power.

[0029] The output of the excitation signal input module 10 is connected to the non-inverting input of the high-voltage operational amplifier module 20 to provide it with a pre-processed RF signal. The output of the high-voltage operational amplifier module 20 is divided into two paths: one path is connected to the input of the power output module 40, and the other path is connected to the input of the feedback adjustment module 30. The output of the feedback adjustment module 30 is connected to the inverting input of the high-voltage operational amplifier module 20 to form a negative feedback closed loop. The output of the power output module 40 is directly connected to a quadrupole to provide the final amplified RF power supply.

[0030] The feedback adjustment module 30 monitors and corrects the signal in real time, reducing environmental interference, ensuring the stability of the quadrupole electric field, and improving the accuracy of ion screening. The high-voltage operational amplifier module 20, combined with the power driver stage 41, can output a peak-to-peak 3000V, 1-3MHz RF signal, meeting the operating requirements of the quadrupole. The modular design simplifies the circuit structure, reduces debugging difficulty, and impedance matching and closed-loop feedback improve signal transmission efficiency, supporting mass production applications.

[0031] Furthermore, the high-voltage operational amplifier module 20 is built based on a high-voltage operational amplifier chip, the output voltage range of which is 100-1000V.

[0032] The high-voltage operational amplifier module 20 uses a high-voltage operational amplifier chip as its core. Its non-inverting input receives the radio frequency signal preprocessed by the excitation signal input module 10, and its inverting input is connected to the feedback signal output by the feedback adjustment module 30. The chip is based on the differential amplification principle, linearly amplifying the radio frequency signal by comparing the difference between the input signal at the non-inverting input and the feedback signal at the inverting input. The power supply module 50 provides a suitable operating voltage for the high-voltage operational amplifier chip, enabling its output voltage range to reach 100-1000V. Simultaneously, the feedback adjustment module 30 monitors the output signal in real time and dynamically adjusts the feedback at the inverting input to stabilize the chip's amplification factor and ensure that the output voltage is accurately controllable within the set range.

[0033] Optionally, the high-voltage operational amplifier chip can be PA119 or PA99.

[0034] By using high-voltage operational amplifier chips with high voltage withstand characteristics and matching power supplies, a wide voltage output range of 100-1000V can be achieved to meet the requirements of quadrupole for high-voltage radio frequency signals.

[0035] The high-gain characteristics of the high-voltage operational amplifier chip ensure that the radio frequency signal is effectively amplified. With the help of the feedback adjustment mechanism, the linearity error is less than 0.5% and the distortion is less than 0.1%, reducing noise interference.

[0036] The closed-loop feedback structure corrects the amplification factor in real time, reduces the impact of temperature and load changes on the output voltage, ensures the stability of the quadrupole electric field, and improves the detection accuracy of the mass spectrometer.

[0037] The wide bandwidth characteristics of the high-voltage operational amplifier chip are adapted to the frequency requirements of radio frequency signals. The output signal can directly drive the power output module 40 to further increase the power and provide a matching radio frequency power supply for the quadrupole.

[0038] Further, see Figure 2 The excitation signal input module 10 includes a signal attenuator 11, a bandpass filter 12, and an impedance matching circuit 13. The input terminal of the signal attenuator 11 is connected to the radio frequency excitation signal source, the output terminal of the signal attenuator 11 is connected to the input terminal of the bandpass filter 12, and the output terminal of the bandpass filter 12 is connected to the non-inverting input terminal of the high-voltage operational amplifier module 20.

[0039] The input of signal attenuator 11 is connected to an RF excitation signal source. A resistor divider network is used to attenuate the strong external RF signal to a range that the high-voltage operational amplifier module 20 can safely handle, thus preventing overload damage to the chip. By reducing the strong signal to a safe range through signal attenuator 11, the high-voltage operational amplifier module 20 is protected from performance abnormalities or damage caused by input overload.

[0040] The input of the bandpass filter 12 is connected to the output of the signal attenuator 11, and its center frequency is the same as the input signal frequency. It filters out harmonics and spurious interference in the attenuated signal, outputting a clean radio frequency signal. The bandpass filter 12 specifically filters out noise, improves signal purity, and reduces interference with mass spectrometry detection results.

[0041] The input of impedance matching circuit 13 is connected to the output of bandpass filter 12. Through a transformer-type matching circuit, the signal impedance is matched to the input impedance of high-voltage operational amplifier module 20, reducing signal reflection and ensuring efficient transmission of the pre-processed signal to the non-inverting input of high-voltage operational amplifier module 20. Impedance matching reduces signal reflection loss, ensuring that the pre-processed signal enters high-voltage operational amplifier module 20 in a low-loss, high-fidelity state, laying the foundation for subsequent amplification and power output.

[0042] The three-level modules are connected sequentially, with independent yet collaborative functions, a compact overall structure, simplified debugging process, and improved circuit stability and mass production efficiency.

[0043] Optionally, the signal attenuator 11 is provided with a resistor voltage divider circuit.

[0044] The input RF signal is attenuated using a resistor divider network. When a strong external RF signal enters through the input terminal, the signal voltage is reduced proportionally according to the resistor ratio, ensuring that the attenuated signal amplitude meets the input range of the high-voltage operational amplifier module 20.

[0045] The resistor divider circuit attenuates strong input signals to the safe operating range of the high-voltage operational amplifier module 20, preventing chip damage due to overvoltage; and ensures that the input signal amplitude matches the linear operating range of the high-voltage operational amplifier module 20.

[0046] Optionally, the bandpass filter 12 is an LC bandpass filter 12, and the center frequency of the LC bandpass filter 12 is consistent with the frequency of the RF signal provided by the RF excitation signal source.

[0047] The LC bandpass filter 12 is a resonant circuit composed of an inductor (L) and a capacitor (C), whose center frequency is the same as the frequency of the radio frequency excitation signal source. When a signal passes through, the LC circuit presents minimum impedance to the center frequency signal, allowing it to pass through efficiently; it presents high impedance to interference signals such as harmonics and noise that deviate from the center frequency, thereby filtering out noise.

[0048] The LC bandpass filter 12 specifically filters out harmonics and external electromagnetic interference in the radio frequency signal, outputting a clean single-frequency signal and reducing the signal-to-noise ratio of subsequent circuits. Through center frequency matching, it ensures that only the target frequency signal passes through, avoiding interference from stray signals on the stability of the quadrupole electric field.

[0049] Optionally, impedance matching device 13 is provided with transformer-type matching circuit.

[0050] By adjusting the turns ratio of the transformer, impedance matching is achieved between the output of the bandpass filter 12 and the input of the high-voltage operational amplifier module 20. The turns ratio is adjusted according to the transformer impedance transformation formula to ensure that the output impedance of the preceding stage matches the input impedance of the following stage, reducing signal reflection loss.

[0051] Impedance matching unit 13 reduces reflection loss during signal transmission between modules, improving the transmission efficiency and integrity of RF signals. After matching, high-voltage operational amplifier module 20 can obtain maximum signal power from the input terminal, avoiding signal distortion or energy waste caused by impedance mismatch.

[0052] Further, see Figure 3 The feedback adjustment module 30 includes a sampling circuit 33, a comparator 32, and an error amplifier 31. The input terminal of the sampling circuit 33 is connected to the output terminal of the high-voltage operational amplifier module 20, the output terminal of the sampling circuit 33 is connected to the first input terminal of the comparator 32, the second input terminal of the comparator 32 is connected to a reference signal source, the output terminal of the comparator 32 is connected to the input terminal of the error amplifier 31, and the output terminal of the error amplifier 31 is connected to the inverting input terminal of the high-voltage operational amplifier module 20.

[0053] The sampling circuit 33 uses a resistor divider network and is connected to the output of the high-voltage operational amplifier module 20 to acquire the amplified radio frequency signal.

[0054] For example, if the high-voltage operational amplifier outputs a 1000V signal, the sampling circuit 33 outputs a 10V signal to the comparator 32 to realize real-time monitoring of the output signal.

[0055] The first input of comparator 32 receives the output signal of sampling circuit 33, and the second input is connected to a preset reference signal source. By comparing the voltage difference between the two, it outputs an error signal proportional to the error. If the sampled signal is higher than the reference signal, comparator 32 outputs a negative error; otherwise, it outputs a positive error.

[0056] The input of error amplifier 31 is connected to the output of comparator 32, amplifying the weak error signal and enhancing its driving capability. The amplified error signal is transmitted to the inverting input of high-voltage operational amplifier module 20, where the amplification factor of the high-voltage operational amplifier is dynamically adjusted through a negative feedback mechanism. If the output signal is too high, the negative feedback is strengthened, causing the amplification factor to decrease; if the output is too low, the negative feedback is weakened, causing the amplification factor to increase.

[0057] By using closed-loop feedback to correct the amplification factor of the high-voltage operational amplifier module 20 in real time, the output signal fluctuation is controlled within ±0.5%, resisting interference such as temperature drift and power supply voltage fluctuation, ensuring the stability of the quadrupole electric field strength, and improving the ion screening accuracy of the mass spectrometer.

[0058] When the output signal is abnormally high, the negative error output by comparator 32 is amplified and strongly suppresses the amplification capability of the high-voltage operational amplifier, quickly reducing the output voltage and preventing damage to the power output module 40 and the quadrupole due to overvoltage.

[0059] By reducing the nonlinear distortion of the high-voltage operational amplifier module 20 through negative feedback, the total harmonic distortion of the output signal is reduced to less than 0.1%, ensuring the waveform purity of the quadrupole RF electric field and reducing the deviation of ion motion trajectory.

[0060] Optionally, the sampling circuit 33 includes a resistor voltage divider sampling circuit 33, with a sampling ratio ranging from 1 / 60 to 1 / 200.

[0061] The resistor voltage divider sampling circuit 33 uses a resistor voltage divider network to connect to the output of the high-voltage operational amplifier module 20, which proportionally attenuates the 100-1000V high-voltage signal to a 1-10V low-voltage signal.

[0062] For example, when the high-voltage operational amplifier outputs 500V, the sampling circuit 33 outputs a 5V signal to the comparator 32 to realize real-time monitoring of the output voltage.

[0063] The voltage divider design of the sampling circuit 331 / 60 to 1 / 200, combined with the 3mV precision comparator 32, enables an error detection resolution of 0.1%FS. Combined with a 10x error amplification, it ensures that the output voltage error of the high-voltage operational amplifier is less than ±0.5%.

[0064] The accuracy of comparator 32 is no greater than 3mV.

[0065] The first input terminal receives the low-voltage signal from the sampling circuit 33, and the second input terminal is connected to a high-precision reference signal source. By comparing the difference between the two, a voltage signal proportional to the error is output; if the sampled signal is higher than the reference value, a negative error is output; otherwise, a positive error is output, with the accuracy controlled within 3mV, ensuring that the error detection resolution reaches the mV level.

[0066] Error amplifier 31 is an operational amplifier with a gain of 10.

[0067] An operational amplifier design is employed to amplify the weak error signal output from comparator 32 by a fixed factor of 10, enhancing the driving capability. The amplified error signal is fed back to the inverting input of the high-voltage operational amplifier module 20, and the amplification factor is dynamically adjusted through negative feedback: when the output voltage is too high, the negative feedback is strengthened, causing the amplification factor to decrease; when it is too low, the negative feedback is weakened, increasing the amplification factor, thus forming a closed-loop control.

[0068] The error amplifier features a 3110x gain design to shorten the adjustment delay and achieve a response time of less than 10μs. This allows for rapid compensation of output fluctuations caused by sudden load changes, thus preventing distortion of the mass spectrometer detection signal.

[0069] Further, see Figure 4 The power output module 40 includes a power driver stage 41 and an output matching network 42. The input terminal of the power driver stage 41 is connected to the output terminal of the high-voltage operational amplifier module 20, the input terminal of the power driver stage 41 is connected to the input terminal of the output matching network 42, and the output terminal of the output matching network 42 is connected to a quadrupole.

[0070] The power driver stage 41 serves as a power buffer stage between the high-voltage operational amplifier module 20 and the output matching network 42, and employs a multi-stage power transistor to form a push-pull amplifier circuit. The RF signal output from the high-voltage operational amplifier module 20 enters through the input terminal, and through the current amplification of the transistors, the signal power is boosted to the watt level required by the quadrupole, satisfying the RF power requirements of the quadrupole electrodes.

[0071] The power driver stage 41 amplifies the milliwatt-level output power of the high-voltage operational amplifier to the watt level, driving the quadrupole electrode to generate a strong radio frequency electric field, which meets the energy requirements for ions to perform high-frequency oscillating motion in the quadrupole, ensuring the stable operation of the ion screening process.

[0072] The output matching network 42 is a π-type or T-type matching network composed of inductors, capacitors, and adjustable resistors. Its input is connected to the output of the power driver stage 41, and its output is directly connected to the quadrupole electrode. By adjusting the parameters of the LC components, the complex impedance of the quadrupole is matched to the optimal output impedance of the power driver stage 41 to achieve maximum power transfer.

[0073] The output matching network 42 reduces the power reflection loss from 30% to below 1% through impedance matching, enabling the RF signal output by the power driver stage 41 to be delivered to the quadrupole with maximum power, avoiding interference from the reflected signal to the front-end circuit, while reducing circuit heat generation and improving system reliability.

[0074] The power driver stage 41 solves the problem of insufficient power, and the output matching network 42 solves the problem of energy transmission efficiency. Together, they convert the radio frequency signal of the high voltage operational amplifier module 20 into the stable and efficient power output required by the quadrupole, providing the core radio frequency electric field drive for the mass spectrometer, which directly affects the ion separation accuracy and detection sensitivity.

[0075] Optionally, the power driver stage 41 is equipped with a transistor with a power of no more than 20W, and the output matching network 42 is equipped with a π-type LC matching circuit.

[0076] The π-type LC matching circuit consists of an input capacitor C1, an inductor L1, and an output capacitor C2 forming a π-type network, connected in series between the output of the power driver stage 41 and the quadrupole electrode. C1 and C2 are adjustable ceramic capacitors (10-100pF), and L1 is a high-frequency magnetic core inductor (1-10μH). Impedance transformation is achieved by adjusting the component parameters.

[0077] The power controllable amplification of the transistor and the precise impedance matching of the π-type LC circuit complement each other, ensuring that the RF power meets the requirements of the quadrupole electric field strength, while improving signal quality through efficient energy transfer and noise suppression, ultimately guaranteeing the mass spectrometer's quality accuracy and detection sensitivity.

[0078] See Figure 5 , Figure 5 Is it like this? Figure 1 The schematic diagram shows another embodiment of the circuit. In this embodiment, the quadrupole RF power amplifier circuit 100 also includes a power module 50.

[0079] The input terminal of the power module 50 is connected to the mains power supply, and the output terminal of the power module 50 is connected to the power supply terminal of the excitation signal input module 10, the power supply terminal of the high voltage operational amplifier module 20, the power supply terminal of the feedback regulation module 30, and the power output module 40, respectively.

[0080] The output of power module 50 is also connected to a quadrupole.

[0081] This application also provides a quadrupole mass spectrometer, including a quadrupole and a quadrupole RF power amplifier circuit 100 as described above. The RF power amplifier circuit obtains an RF excitation signal through an excitation signal input module 10, and then connects to the quadrupole of the quadrupole mass spectrometer through a power output module 40 to provide the quadrupole with a processed RF signal.

[0082] The quadrupole mass spectrometer is equipped with the radio frequency power amplifier circuit described above. The quadrupole and the radio frequency power amplifier circuit are electrically connected through the output terminal of the power output module 40, and the above-described effect is achieved.

[0083] Unlike existing technologies, this application uses a high-voltage operational amplifier module 20 and a feedback adjustment module 30 to form a feedback closed loop, which monitors and adjusts the output signal in real time. This effectively ensures the stability of the output RF signal, reduces the influence of environmental factors on the signal, and enables the quadrupole to form a stable electric field, thus improving the accuracy of ion screening. This application also uses a high-voltage, high-gain high-voltage operational amplifier chip as the core amplification component, giving the circuit good linearity, low output signal distortion, and reducing interference from noise on the mass spectrometry detection results. Furthermore, the power output module 40 provides power boosting, enabling the quadrupole to receive a high-voltage, high-power RF signal, meeting the quadrupole's operational requirements. The RF power amplifier circuit provided in this application adopts a modular design with clearly defined functions for each module. Compared with circuits built with discrete components, the structure is simpler, reducing debugging difficulty and facilitating mass production and application. The quadrupole RF power amplifier circuit 100 provided in this application outputs an RF signal with a stable frequency of 1-3MHz, a peak-to-peak amplitude of up to 3000V, a linearity error of less than 0.5%, and a distortion of less than 0.1%, which can well meet the working requirements of the quadrupole and effectively improve the detection performance of the quadrupole mass spectrometer.

[0084] The above description is merely an embodiment of this application and does not limit the patent scope of this application. Any equivalent structural or procedural transformations made using the content of this application's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this application.

Claims

1. A quadrupole radio frequency power amplifier circuit, characterized in that, The quadrupole RF power amplifier circuit includes: An excitation signal input module is provided, wherein the input terminal of the excitation signal input module is used to connect to a radio frequency excitation signal source to receive the input radio frequency excitation signal and preprocess the radio frequency excitation signal; A high-voltage operational amplifier module, wherein the non-inverting input terminal of the high-voltage operational amplifier module is connected to the output terminal of the excitation signal input module, and is used to amplify the radio frequency excitation signal; A feedback adjustment module is provided, wherein the input terminal of the feedback adjustment module is connected to the output terminal of the high-voltage operational amplifier module, and the output terminal of the feedback adjustment module is connected to the inverting input terminal of the high-voltage operational amplifier module. The feedback adjustment module is used to compare the amplified radio frequency excitation signal with a preset reference signal and generate a feedback signal transmitted to the high-voltage operational amplifier module to adjust the amplification factor of the high-voltage operational amplifier module. A power output module, the input of which is connected to the output of the high-voltage operational amplifier module, and the output of which is connected to a quadrupole, wherein the power output module amplifies the amplified radio frequency excitation signal to output power that matches the quadrupole.

2. The quadrupole RF power amplifier circuit according to claim 1, characterized in that, The high-voltage operational amplifier module is built based on a high-voltage operational amplifier chip, and the output voltage range of the high-voltage operational amplifier chip is 100-1000V.

3. The quadrupole RF power amplifier circuit according to claim 1, characterized in that, The excitation signal input module includes a signal attenuator, a bandpass filter, and an impedance matching device; The input terminal of the signal attenuator is connected to the radio frequency excitation signal source, the output terminal of the signal attenuator is connected to the input terminal of the bandpass filter, and the output terminal of the bandpass filter is connected to the non-inverting input terminal of the high-voltage operational amplifier module.

4. The quadrupole RF power amplifier circuit according to claim 3, characterized in that, The signal attenuator is equipped with a resistor voltage divider circuit; The bandpass filter is an LC bandpass filter, and the center frequency of the LC bandpass filter is consistent with the frequency of the radio frequency signal provided by the radio frequency excitation signal source; The impedance matching device is equipped with a transformer-type matching circuit.

5. The quadrupole RF power amplifier circuit according to claim 1, characterized in that, The feedback adjustment module includes a sampling circuit, a comparator, and an error amplifier; The input terminal of the sampling circuit is connected to the output terminal of the high-voltage operational amplifier module, the output terminal of the sampling circuit is connected to the first input terminal of the comparator, the second input terminal of the comparator is connected to the reference signal source, the output terminal of the comparator is connected to the input terminal of the error amplifier, and the output terminal of the error amplifier is connected to the inverting input terminal of the high-voltage operational amplifier module.

6. The quadrupole RF power amplifier circuit according to claim 5, characterized in that, The sampling circuit includes a resistor voltage divider sampling circuit, with a sampling ratio range of 1 / 60 to 1 / 200; The comparator has an accuracy of no more than 3mV; The error amplifier is an operational amplifier with a magnification of 10.

7. The quadrupole RF power amplifier circuit according to claim 1, characterized in that, The power output module includes a power driver stage and an output matching network; The input terminal of the power driver stage is connected to the output terminal of the high-voltage operational amplifier module, the input terminal of the power driver stage is connected to the input terminal of the output matching network, and the output terminal of the output matching network is connected to the quadrupole.

8. The quadrupole RF power amplifier circuit according to claim 7, characterized in that, The power driver stage is equipped with a transistor with a power of no more than 20W, and the output matching network is equipped with a π-type LC matching circuit.

9. The quadrupole RF power amplifier circuit according to claim 1, characterized in that, The quadrupole RF power amplifier circuit also includes a power module; The input terminal of the power supply module is connected to the mains power supply, and the output terminal of the power supply module is connected to the power supply terminal of the excitation signal input module, the power supply terminal of the high voltage operational amplifier module, the power supply terminal of the feedback adjustment module, and the power output module, respectively. The output terminal of the power module is also connected to the quadrupole.

10. A quadrupole mass spectrometer, characterized in that, The instrument includes a quadrupole and a quadrupole RF power amplifier circuit as described in any one of claims 1-9. The RF power amplifier circuit acquires an RF excitation signal through an excitation signal input module and then connects to the quadrupole of the quadrupole mass spectrometer through a power output module to provide the quadrupole with a processed RF signal.

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