Terahertz wave signal intensity detection method, device, equipment and medium

Abstract

The invention discloses a terahertz wave signal intensity detection method, device and equipment and a medium, and belongs to the field of terahertz weak signal detection.The method comprises the steps that a terahertz wave signal is modulated into a periodic intermittent optical signal through an optical chopper according to a preset chopper modulation frequency; the periodic intermittent optical signal is converted into a voltage signal through a terahertz probe; amplifying the voltage signal through an amplification conditioning circuit, and converting the amplified voltage signal into a digital signal through an analog-to-digital acquisition circuit; through the MCU chip, fast Fourier transform is combined with chopper modulation frequency, the digital signal is analyzed, and the intensity of the terahertz wave signal is obtained. Therefore, by implementing the application, the problems of high hardware cost and low detection speed in the terahertz wave signal intensity detection process can be solved.

Description

Technical Field

[0001] This application relates to the field of terahertz weak signal detection, and in particular to a method, apparatus, equipment and medium for detecting terahertz wave signal intensity. Background Technology

[0002] With advancements in the semiconductor industry and new terahertz high-power radio frequency device technology, stable and reliable frequency excitation sources have been provided for the generation of terahertz waves, opening up more possibilities for the expansion of terahertz wave applications, such as terahertz communication and terahertz imaging. Therefore, the detection of terahertz wave signal strength has become a crucial aspect of terahertz technology applications.

[0003] There are two main types of existing terahertz wave signal intensity detection technologies: one is an optical method that uses an optical power meter to detect the intensity of terahertz waves; the other is a method based on lock-in amplification technology to detect weak terahertz signals. For the first type of method, the optical method for detecting terahertz wave signal intensity has the following three problems: (1) Terahertz optical power meters are expensive, large in size, require high precision, and have high maintenance costs, which is not conducive to the large-scale application of terahertz technology; (2) The detection of terahertz wave signal intensity using a terahertz optical power meter is heavily dependent on optical path adjustment. The terahertz signal needs to be focused to the maximum extent to input the laser power meter in order to accurately detect the terahertz wave signal intensity, resulting in large test errors; (3) The detection speed using a terahertz optical power meter is slow, usually requiring several seconds or even tens of seconds to wait for the incident signal to stabilize. For the second type of method, the detection of weak terahertz signals based on phase-locked loop (PLL) amplification technology has high sensitivity and test accuracy, but there are three problems: (1) the integration time of the PLL circuit is long, usually requiring several seconds to stabilize; (2) the PLL circuit structure is relatively complex, requiring high device accuracy and high hardware cost; (3) the PLL amplification technology is essentially a means of detecting weak signals through electronic circuits. Currently, the electronic devices on the market cannot respond to the entire terahertz frequency band. Therefore, it is necessary to use modulation technology to modulate the terahertz signal to a frequency band that the electronic devices can receive.

[0004] Therefore, how to reduce the hardware cost in the terahertz wave signal intensity detection process while improving detection accuracy and speed is a technical problem that needs to be solved. Summary of the Invention

[0005] This application provides a method, apparatus, device, and medium for detecting terahertz wave signal intensity, which can solve the problem of how to reduce the hardware cost and improve the detection speed in the existing technology.

[0006] This application provides a terahertz wave signal intensity detection method in some embodiments, applied to a terahertz wave signal intensity detection system. The terahertz wave signal intensity detection system includes: an optical chopper, a terahertz probe, an amplification and conditioning circuit, an analog-to-digital acquisition circuit, and an MCU chip. The terahertz wave signal intensity detection method includes: The terahertz wave signal is modulated into a periodic intermittent optical signal by the optical chopper according to the preset chopper modulation frequency. The periodic intermittent optical signal is converted into a voltage signal by the terahertz probe. The voltage signal is amplified by the amplification and conditioning circuit, and the amplified voltage signal is converted into a digital signal by the analog-to-digital acquisition circuit. The intensity of the terahertz wave signal is obtained by analyzing the digital signal using the MCU chip, combined with the fast Fourier transform and the chopper modulation frequency.

[0007] Compared to existing technologies, the above embodiments have the following advantages: Traditional optical power meter testing methods require a stabilization time of several seconds or even tens of seconds; testing schemes using lock-in amplifiers require waiting for the low-pass filter capacitor and integrating capacitor in the lock-in circuit to charge and discharge, also requiring several seconds. This application modulates the terahertz wave signal into a low-frequency signal of periodic intermittent optical signal, thereby enabling further signal processing through signal amplification, signal acquisition, and fast Fourier transform to achieve terahertz wave signal intensity detection. This fundamentally bypasses the inherent limitations of optical power meters and lock-in amplifiers, resulting in faster detection speeds. Furthermore, the solution of this application does not require high-end optical or electronic instruments; it only requires low-cost electronic devices to achieve terahertz wave signal intensity detection, thus requiring lower hardware costs.

[0008] Furthermore, the amplification and conditioning circuit includes: a DC filter circuit, a common-mode filter circuit, an instrumentation amplifier circuit, a power frequency filter circuit, a first inverting proportional voltage amplifier circuit, a second inverting proportional voltage amplifier circuit, an active low-pass filter circuit, and a non-inverting proportional voltage amplifier circuit.

[0009] Compared to existing technologies, the above embodiments have the following advantages: By using an amplification and conditioning link composed of multiple circuits such as DC filtering, common-mode filtering, instrumentation amplification, power frequency filtering, multi-stage proportional amplification, and active low-pass filtering, the voltage signal is purified and amplified in stages. Each stage undertakes the task of suppressing different types of noise or distortion, thus forming a signal channel that can progressively amplify and purify the weak voltage signal output by the terahertz probe. Since the terahertz probe output signal is extremely weak and actual operating conditions are often accompanied by significant DC drift, common-mode interference, power frequency noise, and high-frequency electromagnetic interference, a single-stage circuit cannot handle all noise simultaneously. Therefore, this combined structure can significantly improve the signal-to-noise ratio, ensuring that the low-amplitude terahertz modulation signal remains linear and distortion-free after each stage of purification. Before finally entering the analog-to-digital converter (ADC), the signal has been robustly amplified through multiple stages to an amplitude range that the ADC can accurately recognize, thereby improving the accuracy of subsequent Fast Fourier Transform (FFT) analysis and the overall detection sensitivity of the system.

[0010] Further, the amplification of the voltage signal through the amplification and conditioning circuit includes: The DC component in the voltage signal is filtered out by the DC filter circuit to obtain the first voltage signal; The common-mode filtering circuit suppresses common-mode interference noise in the first voltage signal to obtain the second voltage signal. After the second voltage signal is amplified by the instrumentation amplifier circuit, the power frequency interference in the second voltage signal is filtered out by the power frequency filter circuit to obtain the third voltage signal. After the third voltage signal is amplified by the first inverting proportional voltage amplifier circuit, the high-frequency noise in the third voltage signal is filtered out by the active low-pass filter circuit to obtain the fourth voltage signal. The fourth voltage signal is amplified sequentially by the second inverting voltage amplifier circuit and the non-inverting voltage amplifier circuit.

[0011] Compared to existing technologies, the above embodiments have the following advantages: filtering DC first prevents the subsequent amplifier from being pulled into saturation by large bias; suppressing common-mode interference first improves the extraction effect of weak differential signals by the instrumentation amplifier; filtering power frequency noise immediately after the instrumentation amplifier prevents power frequency interference from being further amplified in subsequent amplification stages; and finally, using a high-frequency low-pass filter suppresses high-frequency interference caused by operational amplifier noise and electromagnetic coupling. Through this progressively refined processing structure, the target signal can be ensured to maintain a high signal-to-noise ratio throughout the entire link, making the FFT peak extracted by the system more accurate and repeatable, and significantly improving the robustness of terahertz signal strength detection.

[0012] Furthermore, the amplification and conditioning circuit further includes: a plurality of impedance matching circuits, wherein the impedance matching circuits are disposed between the input / output ports of any two circuits in the amplification and conditioning circuit and the placement distance between them and the input / output ports is less than a preset distance.

[0013] Compared to existing technologies, the above embodiments have the following advantages: Since weak voltage signals are susceptible to reflection, amplitude distortion, and frequency response fluctuations caused by impedance discontinuities, impedance control between each circuit module can significantly reduce energy loss and phase shift during signal transmission. Simultaneously, multi-stage amplifiers often suffer from inconsistencies in input / output impedance; impedance matching ensures that each amplifier operates within its optimal linear region, preventing amplitude compression or bandwidth reduction due to load effects. Furthermore, impedance matching can reduce the risk of parasitic oscillations in high-gain scenarios, guaranteeing the stability of high-gain links.

[0014] Furthermore, the analog-to-digital acquisition circuit includes: one or more acquisition channels; each acquisition channel corresponds to an analog-to-digital acquisition chip with a certain resolution.

[0015] Compared to existing technologies, the above embodiments offer the following advantages: The multi-channel acquisition design enables the system to select analog-to-digital (ADC) acquisition chips with different resolutions or ranges based on the input signal amplitude, achieving automatic resolution switching. High-resolution channels allow for finer voltage quantization in weak signal scenarios, improving the detection sensitivity for low-amplitude terahertz signals; while when the signal is strong, switching to lower or higher range acquisition channels prevents ADC saturation and maintains a good linear measurement range. The multi-channel structure is equivalent to providing the system with automatic gain control capabilities, thereby expanding the overall measurable range and improving the stability and applicability of the detection.

[0016] Furthermore, the step of analyzing the digital signal using the MCU chip, employing a Fast Fourier Transform combined with the chopper modulation frequency, includes: The MCU chip is used to normalize the digital signal into decimal data to obtain the original signal amplitude voltage. The original signal amplitude voltage is processed by the MCU chip using the Fast Fourier Transform to obtain the frequency domain signal; The MCU chip is used to extract the maximum modulus value within the range corresponding to the chopper modulation frequency. The frequency corresponding to the maximum modulus is determined by the MCU chip based on the maximum modulus and the sampling frequency of the analog-to-digital converter.

[0017] Compared to existing technologies, the above embodiments have the following advantages: By performing a Fast Fourier Transform (FFT) on the normalized time-domain voltage signal and extracting the maximum modulus within a preset modulation frequency window, the acquisition of terahertz intensity is transformed from traditional average power measurement to frequency domain peak extraction. This method can effectively suppress interference from unmodulated noise because only the spectral peaks near the chopper modulation frequency truly represent terahertz light intensity, while all other frequencies are eliminated by FFT decomposition. Furthermore, by matching the FFT output with the sampling frequency of the analog-to-digital acquisition circuit, the digital amplitude can be mapped one-to-one with the actual physical voltage, making the peak values ​​obtained by the system more reliable and quantifiable. This not only significantly improves the detection speed but also enhances the resistance to environmental noise, improving the accuracy and stability of terahertz signal intensity measurement.

[0018] Further, determining the frequency corresponding to the maximum modulus value using the MCU chip, based on the maximum modulus value and the sampling frequency of the analog-to-digital converter (ADC) acquisition circuit, includes: The index value corresponding to the maximum modulus is determined using the MCU chip. The frequency resolution is determined using the MCU chip based on the sampling frequency. The frequency corresponding to the maximum modulus is determined by the MCU chip based on the index value and the frequency resolution.

[0019] Compared to existing technologies, the above embodiments have the following advantages: By using the maximum modulus to correspond to the index and further determining the peak frequency based on the frequency resolution, the discrete frequency points of the FFT are accurately mapped to the actual frequency, enabling the system to determine whether the peak value actually falls near the chopper modulation frequency, thereby verifying the modulation synchronization. This significantly improves the reliability of terahertz signal detection, ensuring that the final output peak amplitude necessarily originates from the true modulated terahertz signal, thus guaranteeing accurate and reliable detection results.

[0020] Another embodiment of this application provides a terahertz wave signal strength detection device, applied to a terahertz wave signal strength detection system, the terahertz wave signal strength detection system including: an optical chopper, a terahertz probe, an amplification and conditioning circuit, an analog-to-digital acquisition circuit, and an MCU chip; the terahertz wave signal strength detection device includes: a terahertz wave signal modulation module, a voltage signal conversion module, a digital signal acquisition module, and a digital signal analysis module; The terahertz wave signal modulation module is used to modulate the terahertz wave signal into a periodic intermittent optical signal according to a preset chopper modulation frequency through the optical chopper. The voltage signal conversion module is used to convert the periodic intermittent optical signal into a voltage signal through the terahertz probe; The digital signal acquisition module is used to amplify the voltage signal through the amplification and conditioning circuit, and to convert the amplified voltage signal into a digital signal through the analog-to-digital acquisition circuit. The digital signal analysis module is used to analyze the digital signal through the MCU chip, using fast Fourier transform combined with the chopper modulation frequency, to obtain the intensity of the terahertz wave signal.

[0021] Another embodiment of this application provides a terminal device, including: a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor. When the processor executes the computer program, it implements the steps of the terahertz wave signal intensity detection method of this application.

[0022] Another embodiment of this application also provides a computer-readable storage medium item, including: a stored computer program, which, when the computer program is running, controls the device where the computer-readable storage medium is located to perform the steps of the terahertz wave signal intensity detection method of this application. Attached Figure Description

[0023] To more clearly illustrate the technical solution of this application, the drawings used in the embodiments 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 from these drawings without creative effort.

[0024] Figure 1 This is a flowchart illustrating a terahertz wave signal intensity detection method provided in some embodiments of this application; Figure 2 This is a schematic diagram of an amplification and conditioning circuit provided in some embodiments of this application; Figure 3This is a schematic diagram of the internal workings of an AD8428 chip provided in some embodiments of this application; Figure 4 This is a schematic diagram of an instrumentation amplifier circuit based on the AD8428 chip provided in some embodiments of this application; Figure 5 This is a schematic diagram of an inverting proportional voltage amplifier circuit provided in some embodiments of this application; Figure 6 This is a schematic diagram of a non-inverting voltage amplifier circuit provided in some embodiments of this application; Figure 7 This is a schematic diagram of a DC filter circuit provided in some embodiments of this application; Figure 8 This is a schematic diagram of a power frequency filter circuit provided in some embodiments of this application; Figure 9 This is a schematic diagram of an active low-pass filter circuit provided in some embodiments of this application; Figure 10 This is a schematic diagram of a common-mode filter circuit provided in some embodiments of this application; Figure 11 This is a schematic diagram of an impedance matching circuit provided in some embodiments of this application; Figure 12 This is a schematic diagram of an analog-to-digital acquisition circuit provided in some embodiments of this application; Figure 13 This is a schematic diagram of the structure of a terahertz wave signal intensity detection device provided in some embodiments of this application. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions of this application will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0026] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms “comprising” and “having”, and any variations thereof, in the specification, claims, and foregoing description of the drawings are intended to cover non-exclusive inclusion.

[0027] In the description of the embodiments of this application, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly defined.

[0028] 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 separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0029] In the description of the embodiments in this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.

[0030] In the description of the embodiments of this application, the term "multiple" refers to two or more (including two), similarly, "multiple sets" refers to two or more (including two sets), and "multiple pieces" refers to two or more (including two pieces).

[0031] In the description of the embodiments of this application, unless otherwise expressly specified and limited, technical terms such as "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. For those skilled in the art, the specific meaning of the above terms in the embodiments of this application can be understood according to the specific circumstances.

[0032] There are two main types of existing terahertz wave signal intensity detection technologies: one is an optical method that uses an optical power meter to detect the intensity of terahertz waves; the other is a method based on lock-in amplification technology to detect weak terahertz signals. For the first type of method, the optical method for detecting terahertz wave signal intensity has the following three problems: (1) Terahertz optical power meters are expensive, large in size, require high precision, and have high maintenance costs, which is not conducive to the large-scale application of terahertz technology; (2) The detection of terahertz wave signal intensity using a terahertz optical power meter is heavily dependent on optical path adjustment. The terahertz signal needs to be focused to the maximum extent to input the laser power meter in order to accurately detect the terahertz wave signal intensity, resulting in large test errors; (3) The detection speed using a terahertz optical power meter is slow, usually requiring several seconds or even tens of seconds to wait for the incident signal to stabilize. For the second type of method, the detection of weak terahertz signals based on phase-locked loop (PLL) amplification technology has high sensitivity and test accuracy, but there are three problems: (1) the integration time of the PLL circuit is long, usually requiring several seconds to stabilize; (2) the PLL circuit structure is relatively complex, requiring high device accuracy and high hardware cost; (3) the PLL amplification technology is essentially a means of detecting weak signals through electronic circuits. Currently, the electronic devices on the market cannot respond to the entire terahertz frequency band. Therefore, it is necessary to use modulation technology to modulate the terahertz signal to a frequency band that the electronic devices can receive.

[0033] Please refer to Figure 1 To address the issues of high hardware costs and slow detection speeds in existing terahertz wave signal intensity detection processes, this application provides a terahertz wave signal intensity detection method, applicable to a terahertz wave signal intensity detection system. The terahertz wave signal intensity detection system includes: an optical chopper, a terahertz probe, an amplification and conditioning circuit, an analog-to-digital acquisition circuit, and an MCU chip.

[0034] According to the Friesian transmission model, the path loss of a terahertz wave signal in free space can be calculated using the following formula: in, The carrier frequency is expressed in GHz. The distance between the transmitter and receiver is in kilometers. According to the formula above, path loss in free space increases significantly with increasing carrier frequency and propagation distance, indicating that high-frequency signals are more prone to attenuation during long-distance transmission. In the terahertz band, the frequency used is as high as 10... 12As shown in the formula above, the path loss is significant. For example, a terahertz signal with a center frequency of 2.52 THz and a power of 100 mW (20 dBm) experiences a path loss of 160.5 dB after 1 m of spatial attenuation, resulting in a received signal of only -140.5 dBm, which is extremely weak. Typically, a signal receiver internally uses an ADC (analog-to-digital converter) sampling circuit. Its signal resolution depends on the ADC sampling accuracy. For a 16-bit ADC chip with a reference voltage of 3.3 V, the minimum resolution is 50 μV. Since terahertz signals are transmitted spatially via an optical chopper and received by a terahertz probe, the signal receiver typically cannot directly identify the target signal. It requires a high-gain, low-noise directional antenna / probe and amplifier to amplify the terahertz signal before sending it to the receiver. Therefore, this application provides a method for detecting terahertz wave signal strength.

[0035] Furthermore, the terahertz wave signal intensity detection method includes steps S101 to S104, specifically: S101: The terahertz wave signal is modulated into a periodic intermittent optical signal by the optical chopper according to the preset chopper modulation frequency.

[0036] Specifically, in some embodiments of this application, the optical chopper is a device similar to a fan or a light-blocking plate with an opening and closing function. At a certain rotational speed or frequency, continuous light can be modulated (chopped) into periodic intermittent light of a certain frequency, with the blocking time equal to the transmission time, thus transforming a constant light source into alternating "square wave" light. Terahertz light has a frequency as high as 10... 12 1kHz is a frequency range far exceeding that of electronic devices. Therefore, for electronic circuits, terahertz light is equivalent to a constant light source and needs to be chopper-modulated to become a signal that electronic devices can process. Typically, the frequency modulated by an optical chopper is within 1kHz.

[0037] S102: The periodic intermittent optical signal is converted into a voltage signal by the terahertz probe.

[0038] S103: The voltage signal is amplified by the amplification and conditioning circuit, and the amplified voltage signal is converted into a digital signal by the analog-to-digital acquisition circuit.

[0039] Furthermore, in some embodiments of this application, the amplification and conditioning circuit includes: a DC filter circuit, a common-mode filter circuit, an instrumentation amplifier circuit, a power frequency filter circuit, a first inverting proportional voltage amplifier circuit, a second inverting proportional voltage amplifier circuit, an active low-pass filter circuit, and a non-inverting proportional voltage amplifier circuit.

[0040] refer to Figure 2The diagram below shows a schematic of a preferred amplification and conditioning circuit provided in some embodiments of this application. In this preferred amplification and conditioning circuit, the DC filter circuit is a 0.5Hz high-pass filter (HPF), the power frequency filter circuit is a 70Hz HPF, and the active low-pass filter circuit is 1MHz. Furthermore, the input and output stages of this preferred amplification and conditioning circuit each include a 50Ω impedance matching circuit.

[0041] Through an amplification and conditioning chain composed of multiple circuits including DC filtering, common-mode filtering, instrumentation amplification, power frequency filtering, multi-stage proportional amplification, and active low-pass filtering, the voltage signal is purified and amplified in stages. Each stage undertakes the task of suppressing different types of noise or distortion, thus forming a signal channel that can progressively amplify and purify the weak voltage signal output by the terahertz probe. Since the terahertz probe output signal is extremely weak and often accompanied by significant DC drift, common-mode interference, power frequency noise, and high-frequency electromagnetic interference in actual operation, a single-stage circuit cannot handle all noise simultaneously. Therefore, this combined structure can significantly improve the signal-to-noise ratio, ensuring that the low-amplitude terahertz modulation signal remains linear and distortion-free after each stage of purification. Before finally entering the analog-to-digital acquisition circuit, the signal has been robustly amplified through multiple stages to an amplitude range that the ADC can accurately recognize, thereby improving the accuracy of subsequent FFT analysis and the overall detection sensitivity of the system.

[0042] Furthermore, in some embodiments of this application, the amplification of the voltage signal through the amplification and conditioning circuit includes: The DC component in the voltage signal is filtered out by the DC filter circuit to obtain the first voltage signal; The common-mode filtering circuit suppresses common-mode interference noise in the first voltage signal to obtain the second voltage signal. After the second voltage signal is amplified by the instrumentation amplifier circuit, the power frequency interference in the second voltage signal is filtered out by the power frequency filter circuit to obtain the third voltage signal. After the third voltage signal is amplified by the first inverting proportional voltage amplifier circuit, the high-frequency noise in the third voltage signal is filtered out by the active low-pass filter circuit to obtain the fourth voltage signal. The fourth voltage signal is amplified sequentially by the second inverting voltage amplifier circuit and the non-inverting voltage amplifier circuit.

[0043] Still with Figure 2Taking the schematic diagram shown as an example, when the voltage signal enters the amplification and conditioning circuit from the terahertz probe, it passes sequentially through the 0.5Hz HPF (i.e., DC filter circuit), the 50Ω impedance matching circuit (i.e., common-mode filter circuit), the instrumentation amplifier circuit, the 70Hz HPF (i.e., power frequency filter circuit), the first inverting amplifier circuit (i.e., the first inverting proportional voltage amplifier circuit), the 1MHz LPF (i.e., active low-pass filter circuit), the second inverting amplifier circuit (i.e., the second inverting proportional voltage amplifier circuit), the non-inverting amplifier circuit (i.e., the non-inverting proportional voltage amplifier circuit), and the 50Ω impedance matching circuit, thereby amplifying the voltage signal.

[0044] As can be seen from the above embodiments, the amplification and conditioning circuit designed in this application includes a four-stage amplification circuit, namely a first-stage instrumentation amplifier circuit, a second-stage first inverting proportional voltage amplifier circuit, a third-stage second inverting proportional voltage amplifier circuit, and a fourth-stage non-inverting proportional voltage amplifier circuit.

[0045] Preferably, in some embodiments, Figure 2 In the schematic diagram shown, the 1MHz active low-pass filter circuit can be placed between the second and third amplification stages, or after the fourth amplification stage and before the output signal.

[0046] Preferably, in some embodiments of this application, the above-mentioned amplification and conditioning circuit can be cascaded with the inverting proportional voltage amplifier circuit and the non-inverting proportional voltage amplifier circuit according to the needs of the actual application scenario, and the amplification factor of each stage can be adjusted. In one preferred embodiment, the first stage uses an AD8428 low-noise instrumentation amplifier circuit with a fixed gain G=2000; in order to reduce the influence of the operational amplifier offset voltage, the second stage amplification is set with a first inverting proportional voltage amplifier circuit with a gain G=5. In the actual debugging process, due to 1e 4 The amplification factor already meets the requirements, so the third stage amplification uses a second inverting proportional voltage amplifier circuit with a gain G=1 to restore the inverted signal from the second stage to positive phase. Since some embodiments of this application use the dual op-amp chip OPA2192, the fourth stage amplification uses a non-inverting proportional amplifier circuit with a gain G=1. The structures of the third and fourth stage amplifier circuits are also reserved for future debugging. The second stage uses inverting amplification to reduce the impact of offset voltage; the offset voltage of the inverting amplifier circuit is smaller than that of the non-inverting circuit. Restoring the signal to positive phase is to recover the phase of the original signal.

[0047] Understandably, the voltage signal needs to be filtered at the power frequency after the first stage of amplification. This is because the original voltage signal is very weak before the first stage of amplification, and the power frequency filter circuit has a large capacitor that isolates the original signal, thus weakening it and affecting the signal-to-noise ratio. Therefore, the original voltage signal needs to be amplified before power frequency filtering. At this point, the amplified signal is less likely to be isolated by the large capacitor of the power frequency filter circuit.

[0048] The first-stage method employs an instrumentation amplifier circuit that is a closed-loop gain circuit composed of one or more operational amplifiers, featuring a pair of differential inputs and a single-ended output. Because the instrumentation amplifier has differential inputs, it offers advantages over operational amplifiers, including higher common-mode rejection ratio, lower linearity error, lower noise, and better stability.

[0049] Preferably, in some embodiments of this application, reference is made to Figure 3 The internal chip of the instrumentation amplifier circuit is the AD8428 fixed-gain instrumentation amplifier chip, and its internal circuitry is based on a traditional three-op-amp topology. (Reference) Figure 3 The schematic diagram of the AD8428 chip shown depicts a two-stage structure. The first stage provides a differential amplifier with a gain of 200x, while the second stage is a differential amplifier structure that eliminates common-mode voltage and provides a gain of 10x. Therefore, the total fixed gain of the AD8428 chip is 2000x (66dB). This chip exhibits extremely low noise, with an input voltage noise of 1.5nV / √Hz, a common-mode rejection ratio of 140dB, a gain accuracy of 0.05%, and a gain temperature drift of 5ppm / ℃.

[0050] refer to Figure 4 This is a preferred instrumentation amplifier circuit used in some embodiments of this application. Its internal chip is the AD8428 chip, which, due to its low noise, high common-mode rejection ratio, and high precision, can effectively improve the receiving sensitivity of the amplification and conditioning circuit, reduce noise, and improve the signal-to-noise ratio at the input. Figure 4 In the circuit shown, Vss+ and Vss- are the power supplies for the AD8428 chip. C3 and C6 are set to blank (NC) as reserved bits for future optimization should reliability issues arise in the system.

[0051] Preferably, in some embodiments of this application, the instrumentation amplifier circuit can be a fixed-gain instrumentation amplifier or a variable-gain instrumentation amplifier, but it is required to have the characteristics of low noise floor and high common-mode rejection ratio.

[0052] It is understandable that the voltage signal is amplified by the second stage and then subjected to active low-pass filtering. This is because the voltage signal strength is strong enough after the second stage of amplification, and additional high-frequency noise may be generated after the first and second stages of amplification. At this time, active low-pass filtering can filter out the high-frequency noise in the original voltage signal as well as the high-frequency noise generated by the nonlinear effects of the previous two stages of amplification circuit, which will have a better benefit on the signal-to-noise ratio of the output signal.

[0053] refer to Figure 5 This is a preferred inverting proportional voltage amplifier circuit provided in some embodiments of this application, wherein adjusting R0106 can adjust the voltage amplification factor, and the specific adjustment principle is as follows: ,in, For output voltage, For input voltage, and These are the resistance values ​​of resistors R0106 and R0105, respectively. It can be understood that both the first and second inverting proportional voltage amplifier circuits can use... Figure 5 The circuit structure shown is shown.

[0054] refer to Figure 6 This is a preferred non-inverting voltage amplifier circuit provided in some embodiments of this application, wherein R0117 can adjust the voltage amplification factor, and the specific adjustment principle is as follows: ,in, and The values ​​are the resistance values ​​of resistors R0117 and R0118, respectively.

[0055] refer to Figure 7 This is a preferred DC filter circuit provided in some embodiments of this application, used to isolate the DC component in the input signal. (See reference...) Figure 8 This is a preferred power frequency filter circuit provided in some embodiments of this application, used to filter out base frequency interference from the mains power (50Hz) in the circuit. (See reference...) Figure 9 This is a preferred active low-pass circuit provided in some embodiments of this application. It is built using an operational amplifier. Since the effective gain bandwidth of the AD8428 chip used in some embodiments of this application is at most 1MHz, it is designed as a 1MHz low-pass filter in some embodiments. In practical applications, it can be set to a low-pass filter with other cutoff frequencies according to circuit requirements. (Reference) Figure 10 This is a preferred common-mode filter circuit provided in some embodiments of this application, used to remove common-mode interference from signals.

[0056] As can be seen from the above embodiments, the amplification and conditioning circuit provided in this application first filters DC to prevent the subsequent amplifier from being pulled into saturation by a large bias; first suppresses common-mode interference to improve the extraction effect of weak differential signals by the instrumentation amplifier; immediately filters out power frequency noise after instrumentation amplification to prevent power frequency interference from being further amplified in subsequent amplification stages; and finally uses a high-frequency low-pass filter to suppress high-frequency interference caused by operational amplifier noise and electromagnetic coupling. Through this processing structure that is progressively refined from shallow to deep, the target signal can be ensured to maintain a high signal-to-noise ratio throughout the entire link, making the FFT peak extracted by the system more accurate and repeatable, and significantly improving the robustness of terahertz signal strength detection.

[0057] Furthermore, in some embodiments of this application, the amplification and conditioning circuit further includes: a plurality of impedance matching circuits, wherein the impedance matching circuits are disposed between the input / output ports of any two circuits in the amplification and conditioning circuit and the placement distance between them and the input / output ports is less than a preset distance.

[0058] Preferably, in some embodiments of this application, the placement distance is controlled within 1-3 mm.

[0059] Preferably, in some embodiments of this application, the impedance matching circuit is 50Ω. (See reference) Figure 2 Impedance matching circuits are placed at both the input and output stages of the amplification and conditioning circuit. Furthermore, impedance matching circuits can also be placed at various stages of the entire amplification and conditioning circuit, specifically between the DC filter circuit, common-mode filter circuit, instrumentation amplifier circuit, power frequency filter circuit, first inverting proportional voltage amplifier circuit, second inverting proportional voltage amplifier circuit, active low-pass filter circuit, and non-inverting proportional voltage amplifier circuit. This is primarily because impedance control of the entire signal link is necessary on the PCB (Printed Circuit Board) to reduce signal distortion and energy loss caused by impedance mismatch.

[0060] refer to Figure 11 This is a 50Ω impedance matching circuit provided in some embodiments of this application. In the schematic diagram, it is designed using a π-shaped network. (Reference) Figure 11 The specific parameter settings of this circuit are determined by adjusting the actual trace length and parasitic effects in the PCB traces. A 50Ω impedance matching circuit is placed at both ends of the signal lines in this design. The start and end points of the signal lines are either the chip's input / output ports or the system's BNC / SMA input / output interfaces. Besides using a π-shaped network in the schematic design, the PCB design also requires controlling the trace width according to the layer stack-up.

[0061] Because weak voltage signals are susceptible to reflections, amplitude distortions, and frequency response fluctuations caused by impedance discontinuities, impedance control between each circuit module can significantly reduce energy loss and phase shift during signal transmission. Furthermore, multi-stage amplifiers often suffer from inconsistencies in input / output impedance; impedance matching ensures that each amplifier stage operates within its optimal linear region, preventing amplitude compression or bandwidth reduction due to load effects. In addition, impedance matching reduces the risk of parasitic oscillations in high-gain scenarios, guaranteeing the stability of high-gain links.

[0062] Furthermore, in some embodiments of this application, the analog-to-digital acquisition circuit includes: one or more acquisition channels; each acquisition channel corresponds to an analog-to-digital acquisition chip with a certain resolution.

[0063] refer to Figure 12 This is a preferred analog-to-digital (ADC) acquisition circuit provided in some embodiments of this application, which utilizes the ADC acquisition function of an STM32H7 chip. However, this application is not limited to the use of STM32; DSP chips and FPGA chips are also applicable. Since the operational amplifier chip in this embodiment is powered by ±5V, the maximum output voltage signal of the amplifier circuit is 5V. The maximum receive voltage signal for the STM32H7's ADC input pin is 3.3V. Therefore, a voltage divider structure is used in the data acquisition circuit. For example... Figure 12 As shown, the input signal Rx1_ADC1 is the output signal after amplification by the amplifier circuit. The maximum theoretical amplitude of this signal is 5V, which exceeds the maximum receiving voltage of the ADC (3.3V). Therefore, R0401 and R0402 are used for voltage division to set the maximum voltage supplied to the ADC to 3.3V. R0404 and R0401 are the filter circuits for the ADC input pin, used to filter out high-frequency noise in the circuit and reduce the noise floor received by the ADC input pin. In this embodiment, the ADC switching is achieved through two switching resistors, R0405 and R0406. The output signals ADC1 and ADC1_1 of the circuit correspond to two ADC acquisition chips with different resolutions, 16-bit and 24-bit, respectively, used for switching between different resolution scenarios. It can be understood that the above analog-to-digital acquisition circuit can be configured with more than two resolution ADC acquisition chips according to actual needs. When the ADC acquisition chip supports multi-channel operation, multiple amplification and conditioning circuits can be added simultaneously to connect to different ADC input ports to achieve multi-channel amplification and acquisition functions.

[0064] The aforementioned multi-channel acquisition design enables the system to select analog-to-digital (ADC) acquisition chips with different resolutions or ranges based on the input signal amplitude, achieving automatic resolution switching. High-resolution channels allow for finer voltage quantization in weak signal scenarios, improving the detection sensitivity for low-amplitude terahertz signals; conversely, when the signal is strong, switching to a lower resolution or larger range acquisition channel prevents ADC saturation and maintains a good linear measurement range. The multi-channel structure effectively provides the system with automatic gain control capabilities, thereby expanding the overall measurable range and improving the stability and applicability of the detection.

[0065] S104: Using the MCU chip, the digital signal is analyzed by combining the Fast Fourier Transform with the chopper modulation frequency to obtain the intensity of the terahertz wave signal.

[0066] Furthermore, in some embodiments of this application, the step of analyzing the digital signal by means of the MCU chip, using a fast Fourier transform combined with the chopper modulation frequency, includes: The MCU chip is used to normalize the digital signal into decimal data to obtain the original signal amplitude voltage. The original signal amplitude voltage is processed by the MCU chip using the Fast Fourier Transform to obtain the frequency domain signal; The MCU chip is used to extract the maximum modulus value within the range corresponding to the chopper modulation frequency. The frequency corresponding to the maximum modulus is determined by the MCU chip based on the maximum modulus and the sampling frequency of the analog-to-digital converter.

[0067] After the analog-to-digital (ADC) acquisition circuit acquires the voltage signal, it converts it into a digital signal. Taking a 16-bit resolution ADC chip as an example, the digital value of the original voltage signal amplitude is 0~65535. Further, when normalizing this digital signal to decimal data, since the reference voltage of the ADC in this embodiment is 3.3V, assuming the digital signal output by the ADC is 'a', the normalized decimal voltage value is... .

[0068] Furthermore, in some embodiments of this application, the step of extracting the maximum modulus value within the range corresponding to the modulation frequency of the chopper specifically involves: assuming the modulation frequency of the optical chopper is... At this point, you can choose an index value of The magnitude value within ±10Hz is taken as the maximum magnitude value, where For frequency resolution, assume the ADC sampling frequency is... If the number of sampling points is n, then It is understandable that the maximum modulus reflects the intensity of the terahertz wave signal. The frequency corresponding to the subsequent maximum modulus can be used to determine the validity of the determined maximum modulus based on its difference from the chopper modulation frequency, thus ensuring the accuracy of the terahertz wave signal intensity detection. Finally, the extracted maximum modulus and frequency of the signal are output through a communication module such as a serial port or Ethernet to achieve the purpose of quickly measuring the terahertz wave intensity.

[0069] By performing a Fast Fourier Transform (FFT) on the normalized time-domain voltage signal and extracting the maximum modulus within a preset modulation frequency window, the acquisition of terahertz intensity is transformed from traditional average power measurement to frequency domain peak extraction. This method effectively suppresses interference from unmodulated noise because only the spectral peaks near the chopper modulation frequency truly represent terahertz light intensity; all other frequencies are eliminated by FFT decomposition. Furthermore, by combining the FFT output with the sampling frequency of the analog-to-digital acquisition circuit, the digital amplitude can be mapped one-to-one with the actual physical voltage, making the peak values ​​obtained by the system more reliable and quantifiable. This not only significantly improves the detection speed but also enhances the resistance to environmental noise, improving the accuracy and stability of terahertz signal intensity measurement.

[0070] Furthermore, in some embodiments of this application, determining the frequency corresponding to the maximum modulus value using the MCU chip based on the maximum modulus value and the sampling frequency of the analog-to-digital converter includes: The index value corresponding to the maximum modulus is determined using the MCU chip. The frequency resolution is determined using the MCU chip based on the sampling frequency. The frequency corresponding to the maximum modulus is determined by the MCU chip based on the index value and the frequency resolution.

[0071] Assuming the current maximum signal magnitude is Mag, and its corresponding index is index, then the frequency corresponding to the maximum signal magnitude is... .

[0072] By using the maximum modulus-to-index method and further determining the peak frequency based on frequency resolution, the discrete frequency points of the FFT are precisely mapped to the actual frequency. This allows the system to determine whether the peak value truly falls near the chopper modulation frequency, thereby verifying modulation synchronization. This significantly improves the reliability of terahertz signal detection, ensuring that the final output peak amplitude necessarily originates from the actual modulated terahertz signal, thus guaranteeing accurate and reliable detection results.

[0073] In summary, the terahertz wave signal intensity detection method provided in this application has the following advantages compared to existing technologies: Traditional optical power meter testing methods require a stabilization time of several seconds or even tens of seconds; testing schemes using lock-in amplifiers require waiting for the low-pass filter capacitor and integrating capacitor in the lock-in circuit to charge and discharge, also requiring several seconds. This application modulates the terahertz wave signal into a low-frequency signal of periodic intermittent optical signals, thereby enabling further signal processing through signal amplification, signal acquisition, and fast Fourier transform to achieve terahertz wave signal intensity detection. This fundamentally bypasses the inherent limitations of optical power meters and lock-in amplifiers, resulting in faster detection speeds. Furthermore, the solution in this application does not require high-end optical or electronic instruments; it only requires low-cost electronic components to achieve terahertz wave signal intensity detection, thus requiring lower hardware costs.

[0074] like Figure 2 As shown, based on the above-described method embodiments, this application provides a terahertz wave signal intensity detection device applied to a terahertz wave signal intensity detection system. The terahertz wave signal intensity detection system includes: an optical chopper, a terahertz probe, an amplification and conditioning circuit, an analog-to-digital acquisition circuit, and an MCU chip. The terahertz wave signal intensity detection device includes: a terahertz wave signal modulation module 201, a voltage signal conversion module 202, a digital signal acquisition module 203, and a digital signal analysis module 204. The terahertz wave signal modulation module 201 is used to, through the optical chopper, according to... A preset chopper modulation frequency modulates the terahertz wave signal into a periodic intermittent optical signal; the voltage signal conversion module 202 converts the periodic intermittent optical signal into a voltage signal through the terahertz probe; the digital signal acquisition module 203 amplifies the voltage signal through the amplification and conditioning circuit, and converts the amplified voltage signal into a digital signal through the analog-to-digital acquisition circuit; the digital signal analysis module 204 analyzes the digital signal using the MCU chip, employing a fast Fourier transform combined with the chopper modulation frequency, to obtain the intensity of the terahertz wave signal.

[0075] Furthermore, in some embodiments of this application, the amplification and conditioning circuit includes: a DC filter circuit, a common-mode filter circuit, an instrumentation amplifier circuit, a power frequency filter circuit, a first inverting proportional voltage amplifier circuit, a second inverting proportional voltage amplifier circuit, an active low-pass filter circuit, and a non-inverting proportional voltage amplifier circuit.

[0076] Further, in some embodiments of this application, the digital signal acquisition module 203 includes: a first filtering unit, a second filtering unit, a first amplification unit, a second amplification unit, and a third amplification unit; the digital signal acquisition module 203 is used to amplify the voltage signal through the amplification and conditioning circuit, including: the first filtering unit is used to filter out the DC component in the voltage signal through the DC filtering circuit to obtain a first voltage signal; the second filtering unit is used to suppress common-mode interference noise in the first voltage signal through the common-mode filtering circuit to obtain a second voltage signal; the first amplification unit is used to amplify the second voltage signal through the instrumentation amplifier amplification circuit and then filter out the power frequency interference in the second voltage signal through the power frequency filtering circuit to obtain a third voltage signal; the second amplification unit is used to amplify the third voltage signal through the first inverting proportional voltage amplifier circuit and then filter out the high-frequency noise in the third voltage signal through the active low-pass filter circuit to obtain a fourth voltage signal; the third amplification unit is used to amplify the fourth voltage signal sequentially through the second inverting proportional voltage amplifier circuit and the non-inverting proportional voltage amplifier circuit.

[0077] Furthermore, in some embodiments of this application, the amplification and conditioning circuit further includes: a plurality of impedance matching circuits, wherein the impedance matching circuits are disposed between the input / output ports of any two circuits in the amplification and conditioning circuit and the placement distance between them and the input / output ports is less than a preset distance.

[0078] Furthermore, in some embodiments of this application, the analog-to-digital acquisition circuit includes: one or more acquisition channels; each acquisition channel corresponds to an analog-to-digital acquisition chip with a certain resolution.

[0079] Further, in some embodiments of this application, the digital signal analysis module 204 includes: a normalization unit, an FFT unit, a maximum modulus extraction unit, and a frequency calculation unit; the digital signal analysis module 204 is used to analyze the digital signal by using the MCU chip and employing Fast Fourier Transform combined with the chopper modulation frequency, including: the normalization unit is used to normalize the digital signal into decimal data by using the MCU chip to obtain the original signal amplitude voltage; the FFT unit is used to process the original signal amplitude voltage by using the Fast Fourier Transform by the MCU chip to obtain a frequency domain signal; the maximum modulus extraction unit is used to extract the maximum modulus within the range corresponding to the chopper modulation frequency by using the MCU chip; the frequency calculation unit is used to determine the frequency corresponding to the maximum modulus by using the MCU chip based on the maximum modulus and the sampling frequency of the analog-to-digital acquisition circuit.

[0080] Furthermore, in some embodiments of this application, the maximum modulus extraction unit is used to determine the frequency corresponding to the maximum modulus by means of the MCU chip, based on the maximum modulus and the sampling frequency of the analog-to-digital acquisition circuit, including: determining the index value corresponding to the maximum modulus by means of the MCU chip; determining the frequency resolution by means of the MCU chip based on the sampling frequency; and determining the frequency corresponding to the maximum modulus by means of the MCU chip based on the index value and the frequency resolution.

[0081] It is understood that the above-described device embodiments correspond to the method embodiments of this application, and can implement the terahertz wave signal intensity detection method provided by any of the above-described method embodiments of this application.

[0082] In summary, the terahertz wave signal intensity detection device provided in this application has the following advantages compared to existing technologies: Traditional optical power meter testing methods require waiting for several seconds or even tens of seconds for stabilization; testing schemes using lock-in amplifiers require waiting for the low-pass filter capacitor and integrating capacitor in the lock-in circuit to charge and discharge, also requiring several seconds. This application modulates the terahertz wave signal into a low-frequency signal of periodic intermittent optical signals, thereby enabling further signal processing through signal amplification, signal acquisition, and fast Fourier transform to achieve terahertz wave signal intensity detection. This fundamentally bypasses the inherent limitations of optical power meters and lock-in amplifiers, resulting in faster detection speeds. Furthermore, the solution in this application does not require high-end optical or electronic instruments; it only requires low-cost electronic components to achieve terahertz wave signal intensity detection, thus requiring lower hardware costs.

[0083] It should be noted that the device embodiments described above are merely illustrative, and some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Furthermore, in the accompanying drawings of the device embodiments provided in this application, the connection relationships between modules indicate that they have communication connections, which can specifically be implemented as one or more communication buses or signal lines. Those skilled in the art can understand and implement this without any creative effort.

[0084] Based on the above embodiments of the terahertz wave signal intensity detection method, another embodiment of this application provides a terminal device, which includes a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor. When the processor executes the computer program, it implements the terahertz wave signal intensity detection method of any embodiment of this application.

[0085] For example, in this embodiment, the computer program can be divided into one or more modules, which are stored in the memory and executed by the processor to complete this application. The one or more module units may be a series of computer program instruction segments capable of performing a specific function, which describe the execution process of the computer program in the terminal device.

[0086] The terminal device may be a desktop computer, laptop, handheld computer, or cloud server, etc. The terminal device may include, but is not limited to, a processor and a memory.

[0087] The processor can be a Central Processing Unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor can be a microprocessor or any conventional processor. The processor is the control center of the terminal device, connecting all parts of the terminal device via various interfaces and lines.

[0088] Based on the above-described method embodiments, another embodiment of this application provides a computer-readable storage medium including a stored computer program, wherein, when the computer program is executed, it controls the device where the computer-readable storage medium is located to execute the terahertz wave signal intensity detection method described in any of the above-described method embodiments of this application.

[0089] The modules / units integrated in the device / terminal equipment, if implemented as software functional units and sold or used as independent products, can be stored in a computer-readable storage medium. Based on this understanding, all or part of the processes in the methods of the above embodiments can also be implemented by a computer program instructing related hardware. The computer program can be stored in a computer-readable storage medium, and when executed by a processor, it can implement the steps of the various method embodiments described above. The computer program includes computer program code, which can be in the form of source code, object code, executable files, or certain intermediate forms. The computer-readable medium can include: any entity or device capable of carrying the computer program code, recording media, USB flash drives, portable hard drives, magnetic disks, optical disks, computer memory, read-only memory (ROM), random access memory (RAM), electrical carrier signals, telecommunication signals, and software distribution media, etc.

Claims

1. A method for detecting intensity of a terahertz wave signal, characterized by, The application is applied to a terahertz wave signal intensity detection system, the terahertz wave signal intensity detection system comprises a light chopper, a terahertz probe, an amplification conditioning circuit, an analog-digital acquisition circuit and an MCU chip, and the terahertz wave signal intensity detection method comprises the following steps: The terahertz wave signal is modulated into a periodic discontinuous light signal by the light chopper according to a preset chopper modulation frequency. The periodic discontinuous light signal is converted into a voltage signal by the terahertz probe. The voltage signal is amplified by the amplification conditioning circuit, and the amplified voltage signal is converted into a digital signal by the analog-digital acquisition circuit. The intensity of the terahertz wave signal is obtained by analyzing the digital signal by the MCU chip by using fast Fourier transform combined with the chopper modulation frequency.

2. The method of claim 1, wherein, The amplification conditioning circuit comprises a direct current filter circuit, a common mode filter circuit, an instrument amplifier amplification circuit, a power frequency filter circuit, a first inverting proportional voltage amplification circuit, a second inverting proportional voltage amplification circuit, an active low-pass filter circuit and a same-phase proportional voltage amplification circuit.

3. The method of claim 2, wherein the step of detecting the intensity of the terahertz wave signal is performed by a terahertz wave signal intensity detector. The voltage signal is amplified by the amplification conditioning circuit, which comprises the following steps: The direct current component in the voltage signal is filtered out by the direct current filter circuit to obtain a first voltage signal. The common mode interference noise in the first voltage signal is suppressed by the common mode filter circuit to obtain a second voltage signal. After the second voltage signal is amplified by the instrument amplifier amplification circuit, the power frequency interference in the second voltage signal is filtered out by the power frequency filter circuit to obtain a third voltage signal. After the third voltage signal is amplified by the first inverting proportional voltage amplification circuit, the high-frequency noise in the third voltage signal is filtered out by the active low-pass filter circuit to obtain a fourth voltage signal. The fourth voltage signal is amplified by the second inverting proportional voltage amplification circuit and the same-phase proportional voltage amplification circuit in sequence.

4. The method of claim 2, wherein the step of detecting the intensity of the terahertz wave signal is performed by a terahertz wave signal intensity detector. The amplification conditioning circuit further comprises a plurality of impedance matching circuits, which are arranged between the input / output ports of any two circuits in the amplification conditioning circuit and have a distance less than a preset distance from the input / output ports.

5. The method of claim 1, wherein the step of detecting the intensity of the terahertz wave signal is performed by a terahertz wave signal intensity detector. The analog-digital acquisition circuit comprises one or more acquisition channels, and each acquisition channel corresponds to an analog-digital acquisition chip with a certain resolution.

6. The method of claim 1, wherein, The digital signal is analyzed by the MCU chip by using fast Fourier transform combined with the chopper modulation frequency, which comprises the following steps: The digital signal is normalized to decimal data by the MCU chip to obtain an original signal amplitude voltage. The original signal amplitude voltage is processed by the MCU chip by using the fast Fourier transform to obtain a frequency domain signal. The maximum modulus value is extracted by the MCU chip within the range corresponding to the chopper modulation frequency. The frequency corresponding to the maximum modulus value is determined by the MCU chip according to the maximum modulus value and the sampling frequency of the analog-digital acquisition circuit.

7. The method of claim 6, wherein the step of detecting the intensity of the terahertz wave signal is performed by a terahertz wave signal intensity detector. The MCU chip determines the index value corresponding to the maximum modulus value. The MCU chip determines the frequency resolution according to the sampling frequency. The MCU chip determines the frequency corresponding to the maximum modulus value according to the index value and the frequency resolution. The application is applied to a terahertz wave signal intensity detection system, and the terahertz wave signal intensity detection system comprises an optical chopper, a terahertz probe, an amplification conditioning circuit, an analog-digital acquisition circuit and an MCU chip.

8. A terahertz wave signal strength detection device, characterized by, The terahertz wave signal modulation module is configured to modulate a terahertz wave signal into a periodic intermittent light signal by the optical chopper according to a preset chopper modulation frequency. The voltage signal conversion module is configured to convert the periodic intermittent light signal into a voltage signal by the terahertz probe. The digital signal acquisition module is configured to amplify the voltage signal by the amplification conditioning circuit and convert the amplified voltage signal into a digital signal by the analog-digital acquisition circuit. The digital signal analysis module is configured to analyze the digital signal by the MCU chip to obtain the intensity of the terahertz wave signal by using fast Fourier transform combined with the chopper modulation frequency. The computer readable storage medium comprises a stored computer program, wherein the computer program controls the device where the computer readable storage medium is located to perform the terahertz wave signal intensity detection method according to any one of claims 1 to 7 when the computer program runs.

9. A terminal device, comprising: ​ 10. A computer-readable storage medium, characterized in that, ​

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