A high-sensitivity, large-dynamic, anti-interference low-frequency receiving device

Abstract

The present application discloses a high-sensitivity, large-dynamic, anti-interference low-frequency receiving device, which includes: a tuning and amplifying module, a frequency conversion amplifying module, a signal processing module and a main control module; the tuning and amplifying module, the frequency conversion amplifying module, the signal processing module and the main control module are connected in sequence; the tuning and amplifying module is used to respond to the first control signal of the main control module to perform denoising and amplification processing on the low-frequency electromagnetic input signal to obtain a low-frequency electromagnetic transition signal; the frequency conversion amplifying module is used to respond to the second control signal of the main control module to perform narrow-band filtering and differential amplification processing on the low-frequency electromagnetic transition signal after frequency conversion processing to obtain an intermediate frequency electromagnetic signal; the signal processing module is used to respond to the third control signal of the main control module to synchronize, demodulate and decode the intermediate frequency electromagnetic signal to obtain a target transmission signal; the main control module is used to generate the first control signal, the second control signal and the third control signal. Each module of the present invention is relatively independent, which is convenient for maintenance and maintenance.

Description

Technical Field

[0001] The present application relates to the field of communication transmission technology, and more specifically, to a high-sensitivity, large-dynamic, anti-interference low-frequency receiving device. Background Art

[0002] Low-frequency (10kHz-100kHz) radio propagates in the Earth-ionosphere waveguide. It has stable propagation, is not affected by nuclear explosions and ionosphere disturbances, has low propagation attenuation in the atmosphere, and is suitable for long-distance communication and underwater communication. After long-distance transmission and attenuation in water, low-frequency signals are weak, and high-sensitivity reception is extremely important. At the same time, due to the large-scale use of electrical equipment and high-power switching power supplies, the low-frequency electromagnetic environment is becoming increasingly complex, and low-frequency electromagnetic interference affects the reception effect, so low-frequency reception interference is particularly serious.

[0003] In the existing technology, the direct amplification of low-frequency electromagnetic signals is limited by the gain of the whole machine and has the problem of low sensitivity. When the bandwidth covers the low-frequency bandwidth (10kHz-100kHz), the interference is large and the anti-interference ability is weak. Usually, 2-3 times frequency conversion superheterodyne can be designed for reception, and narrow bandwidth crystals can be used for filtering to improve the anti-interference ability.

[0004] However, when a 2-3 times frequency conversion superheterodyne device or circuit is designed in a device or system to receive low-frequency electromagnetic signals, the overall size of the receiving device becomes larger and the circuit structure becomes more complex, which increases the complexity of the overall device. It is inconvenient to maintain and service the high-sensitivity, large-dynamic, anti-interference low-frequency receiving device, and the gain cannot be automatically adjusted for amplification. Summary of the invention

[0005] In response to at least one defect or improvement need in the prior art, the present invention provides a high-sensitivity, large-dynamic, anti-interference low-frequency receiving device, which is used to solve the problem that when a frequency-converting superheterodyne device or circuit is used to receive a low-frequency electromagnetic signal in the prior art, the overall volume of the receiving device is large, the circuit structure is complex, and it is inconvenient to maintain and service the high-sensitivity, large-dynamic, anti-interference low-frequency receiving device.

[0006] To achieve the above object, according to a first aspect of the present invention, a high-sensitivity, large-dynamic, anti-interference low-frequency receiving device is provided, comprising: a tuning and amplifying module, a frequency conversion amplifying module, a signal processing module and a main control module; the tuning and amplifying module, the frequency conversion amplifying module, the signal processing module and the main control module are connected in sequence; The tuning and amplification module is used to respond to the first control signal of the main control module to perform denoising and amplification processing on the low-frequency electromagnetic input signal to obtain a low-frequency electromagnetic transition signal; The frequency conversion and amplification module is used to respond to the second control signal of the main control module to perform frequency conversion processing on the low-frequency electromagnetic transition signal, and then perform narrow-band filtering processing and differential amplification processing to obtain an intermediate frequency electromagnetic signal; The signal processing module is used to respond to the third control signal of the main control module to synchronize, demodulate and decode the intermediate frequency electromagnetic signal to obtain a target transmission signal; The main control module is used to generate a first control signal, a second control signal and a third control signal, and receive a target transmission signal.

[0007] In a possible implementation, the first control signal includes an attenuation control signal and a tuning control signal; the tuning amplification module further includes: a passive filtering unit, a multi-stage pre-attenuator, a tuning circuit and a tuning amplifier; the passive filtering unit, the multi-stage pre-attenuator, the tuning circuit and the tuning amplifier are connected in sequence; Wherein, the passive filter unit is used to filter out interference signals outside the preset bandwidth range in the low-frequency electromagnetic input signal; The multi-stage pre-attenuator is used to select the attenuation stage according to the attenuation control signal to attenuate the low-frequency electromagnetic input signal after passive filtering; The tuning circuit is used to tune the attenuated low-frequency electromagnetic input signal within a preset frequency range according to the tuning control signal; The tuned amplifier is used to amplify the tuned low-frequency electromagnetic input signal to obtain a low-frequency electromagnetic transition signal.

[0008] In a possible implementation, the tuning circuit includes a plurality of inductors connected in series and a plurality of capacitors connected in parallel.

[0009] In a possible implementation, the tuned amplifier further includes: a matching transformer, a low noise amplifier and a first effective value detection circuit; the matching transformer, the low noise amplifier and the first effective value detection circuit are connected in sequence; the first effective value detection circuit is also connected to the main control module; The matching transformer is used to amplify the tuned low-frequency electromagnetic input signal according to a preset magnification; The low noise amplifier is used to perform low noise amplification processing on the low frequency electromagnetic input signal after amplification by a preset magnification to obtain a low frequency electromagnetic transition signal; The first effective value detection circuit is used to input the low-frequency electromagnetic transient signal to the main control module to determine whether the signal is saturated.

[0010] In a possible implementation, the frequency conversion amplification module further includes: a frequency mixing circuit, a first narrowband crystal filter, a first automatic gain control circuit, a second narrowband crystal filter, a second automatic gain control circuit, a differential amplifier and a second effective value detection circuit; the frequency mixing circuit, the first narrowband crystal filter, the first automatic gain control circuit, the second narrowband crystal filter, the second automatic gain control circuit, the differential amplifier and the second effective value detection circuit are connected in sequence; the frequency mixing circuit is also connected to the signal processing module; the second effective value detection circuit is also connected to the main control module; The mixing circuit is used to mix the local oscillator signal sent by the signal processing module with the low-frequency electromagnetic transition signal to obtain a mixed signal; The first narrowband crystal filter and the second narrowband crystal filter are used to perform narrowband filtering on the mixed frequency signal; The first automatic gain control circuit and the second automatic gain control circuit are used to adjust the amplification gain to amplify the mixed signal; The differential amplifier is used to perform differential amplification processing on the amplified mixed signal to obtain an intermediate frequency electromagnetic signal; The second effective value detection circuit is used to input the intermediate frequency electromagnetic signal to the main control module to determine whether the signal is saturated.

[0011] In a possible implementation, the first automatic gain control circuit and the second automatic gain control circuit are also connected to the main control module; the first automatic gain control circuit transmits the first gain to the main control module; the second automatic gain control circuit transmits the second gain to the main control module.

[0012] In a possible implementation, the signal processing module further includes: an analog-to-digital converter, a local oscillator generation unit, a digital signal processor, and a field programmable gate array; the analog-to-digital converter, the field programmable gate array, the digital signal processor, and the local oscillator generation unit are connected in sequence; The analog-to-digital converter is used to convert the intermediate frequency electromagnetic signal into an intermediate frequency digital signal according to a preset clock signal and send it to the field programmable gate array; The field programmable gate array is used to down-convert the intermediate frequency digital signal into a baseband signal, then digitally filter the baseband signal and transmit it to the digital signal processor, and decode the baseband signal demodulated by the digital signal processor to obtain the target transmission signal; The digital signal processor is used to synchronize and demodulate the filtered baseband signal and transmit it to the field programmable gate array; The local oscillator generating unit is used to generate a local oscillator signal.

[0013] In a possible implementation, the signal processing module further includes: a crystal oscillator; the crystal oscillator is connected to the analog-to-digital converter; and the crystal oscillator is used to generate a preset clock signal according to an external clock signal.

[0014] In one possible implementation, the signal processing module includes a static random access memory and a dynamic random access memory; the static random access memory stores data and programs in the field programmable gate array and the digital signal processor by connecting to the field programmable gate array and the digital signal processor; the dynamic random access memory stores data and programs in the field programmable gate array and the digital signal processor by connecting to the field programmable gate array and the digital signal processor.

[0015] In a possible implementation, the main control module includes a central processing unit; the central processing unit is used to generate a variety of control signals and control the tuning and amplification module, the frequency conversion amplification module, and the signal processing module through an I / O bus.

[0016] In general, the above technical solutions conceived by the present invention can achieve the following beneficial effects compared with the prior art: The present invention provides a high-sensitivity, large-dynamic, anti-interference low-frequency receiving device, which can respond to the control signal of the main control module through the tuning and amplification module, and perform denoising and amplification processing on the low-frequency electromagnetic input signal, which can effectively remove the noise component in the signal, enhance the signal strength, and provide high-quality input for subsequent signal processing. After the frequency conversion amplification module performs frequency conversion processing on the low-frequency electromagnetic transition signal, it performs narrowband filtering processing and differential amplification processing to obtain an intermediate frequency electromagnetic signal, which not only converts the signal frequency to a frequency band more suitable for processing, but also further removes noise and interference through narrowband filtering, thereby improving the purity and stability of the signal. The signal processing module synchronizes, demodulates and decodes the intermediate frequency electromagnetic signal to obtain the target transmission signal, ensuring the accurate reception and analysis of the signal, and providing a reliable basis for subsequent data processing and analysis. The modular design is adopted to separate the functional modules such as tuning amplification, frequency conversion amplification, signal processing and main control, so that each module can work independently without affecting each other, which is convenient for maintenance and maintenance. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0018] Figure 1 A schematic structural diagram of an embodiment of a high-sensitivity, large-dynamic, anti-interference low-frequency receiving device provided by the present invention; Figure 2 A schematic structural diagram of an embodiment of a tuning and amplification module provided by the present invention; Figure 3 A circuit diagram of an embodiment of a tuning circuit provided by the present invention; Figure 4 A schematic structural diagram of an embodiment of a tuned amplifier provided by the present invention; Figure 5 A schematic structural diagram of an embodiment of a frequency conversion amplification module provided by the present invention; Figure 6 A schematic structural diagram of an embodiment of a signal processing module provided by the present invention. DETAILED DESCRIPTION

[0019] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0020] The terms "first", "second", "third", etc. in the specification and claims of this application and the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. 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 optionally includes steps or units that are not listed, or optionally includes other steps or units inherent to these processes, methods, products or devices.

[0021] See also Figure 1 , Figure 1 A structural diagram of an embodiment of a high-sensitivity, large-dynamic, anti-interference low-frequency receiving device provided by the present invention. In a specific embodiment of the present invention, a high-sensitivity, large-dynamic, anti-interference low-frequency receiving device is disclosed, comprising: a tuning and amplifying module 100, a frequency conversion amplifying module 200, a signal processing module 300 and a main control module 400; the tuning and amplifying module 100, the frequency conversion amplifying module 200, the signal processing module 300 and the main control module 400 are connected in sequence; The tuning and amplification module 100 is used to perform denoising and amplification processing on the low-frequency electromagnetic input signal in response to the first control signal of the main control module 400 to obtain a low-frequency electromagnetic transition signal; The frequency conversion and amplification module 200 is used to respond to the second control signal of the main control module 400 to convert the low-frequency electromagnetic transition signal into a frequency signal, and then perform narrow-band filtering and differential amplification processing to obtain an intermediate-frequency electromagnetic signal; The signal processing module 300 is used to synchronize, demodulate and decode the intermediate frequency electromagnetic signal in response to the third control signal of the main control module 400 to obtain a target transmission signal; The main control module 400 is used to generate a first control signal, a second control signal and a third control signal, and receive a target transmission signal.

[0022] In the above embodiment, after receiving the first control signal sent by the main control module 400, the tuning and amplification module 100 can respond quickly and perform accurate denoising and amplification processing on the low-frequency electromagnetic input signal, which not only effectively eliminates the interference components in the signal, such as background noise, electromagnetic interference, etc., but also significantly enhances the amplitude of the signal, providing a clear and strong enough low-frequency electromagnetic transition signal for subsequent signal processing.

[0023] The frequency conversion amplifier module 200 is responsible for frequency conversion processing of the low-frequency electromagnetic transition signal output by the tuning amplifier module 100. After receiving the second control signal from the main control module 400, the frequency conversion amplifier module 200 will start its frequency conversion function and convert the frequency of the signal to a frequency band more suitable for subsequent processing. Then, the narrowband filter in the module will further filter the frequency-converted signal to remove any residual noise and interference. The differential amplifier circuit ensures the stability and anti-interference ability of the signal during transmission, and finally outputs a clear and stable intermediate frequency electromagnetic signal.

[0024] After receiving the third control signal from the main control module 400, the signal processing module 300 will synchronize, demodulate and decode the intermediate frequency electromagnetic signal. The synchronization process ensures the timing accuracy of the signal, the demodulation process is responsible for extracting useful information from the signal, and the decoding process is to convert this information into a readable format, and finally obtain the target transmission signal. This process requires not only high precision and high efficiency, but also powerful algorithm support to ensure accurate reception and analysis of the signal.

[0025] The main control module 400 is responsible for generating and sending control signals to each module, and receiving the target transmission signal output by the signal processing module 300. The main control module 400 can monitor the working status of the entire receiving device in real time through the built-in processor and control system, and adjust the parameters of the control signal as needed to ensure the stable operation and optimal performance of the entire system. In addition, the main control module 400 also has fault diagnosis and self-protection functions, and can take timely measures when abnormalities are detected to protect the entire receiving device from damage.

[0026] In a specific embodiment of the present invention, the minimum gain of the present invention is 16dB, the maximum gain is 142dB, and a 10nV signal can be amplified to 100mV. The input noise of the present invention is no more than 1.3nV / Hz1 / 2. The bandwidth of the first narrowband crystal filter and the second narrowband crystal filter is 480H, and the 400Hz bandwidth communication signal can pass smoothly, filtering out the out-of-band signal that deviates from the operating frequency 600Hz signal, while the tuning amplifier filter has no suppression ability for deviations from the operating frequency 600Hz, and is used to suppress interference at the far end of the operating frequency, compensating for the problem of insufficient suppression of the narrowband crystal filter at the far end of the operating frequency.

[0027] Compared with the prior art, the embodiment provides a high-sensitivity, large-dynamic, anti-interference low-frequency receiving device. The tuning and amplification module 100 can respond to the control signal of the main control module 400, and perform denoising and amplification processing on the low-frequency electromagnetic input signal, which can effectively remove the noise component in the signal, enhance the signal strength, and provide high-quality input for subsequent signal processing. After the frequency conversion amplification module 200 performs frequency conversion processing on the low-frequency electromagnetic transition signal, it performs narrowband filtering processing and differential amplification processing to obtain an intermediate frequency electromagnetic signal, which not only converts the signal frequency to a frequency band more suitable for processing, but also further removes noise and interference through narrowband filtering, thereby improving the purity and stability of the signal. The signal processing module 300 synchronizes, demodulates and decodes the intermediate frequency electromagnetic signal to obtain the target transmission signal, ensuring the accurate reception and analysis of the signal, and providing a reliable basis for subsequent data processing and analysis. The modular design is adopted to separate the functional modules such as tuning and amplification, frequency conversion amplification, signal processing and main control, so that each module can work independently without affecting each other, which is convenient for maintenance and maintenance.

[0028] See also Figure 2 , Figure 2 The structure diagram of an embodiment of the tuning and amplification module provided by the present invention is as follows. In some embodiments of the present invention, the first control signal includes an attenuation control signal and a tuning control signal; the tuning and amplification module 100 also includes: a passive filtering unit 110, a multi-stage pre-attenuator 120, a tuning circuit 130 and a tuning amplifier 140; the passive filtering unit 110, the multi-stage pre-attenuator 120, the tuning circuit 130 and the tuning amplifier 140 are connected in sequence; Wherein, the passive filtering unit 110 is used to filter out interference signals outside a preset bandwidth range in the low-frequency electromagnetic input signal; The multi-level pre-attenuator 120 is used to select the attenuation level according to the attenuation control signal to attenuate the low-frequency electromagnetic input signal after passive filtering; The tuning circuit 130 is used to tune the attenuated low-frequency electromagnetic input signal within a preset frequency range according to the tuning control signal; The tuned amplifier 140 is used to amplify the tuned low-frequency electromagnetic input signal to obtain a low-frequency electromagnetic transition signal.

[0029] In the above embodiment, the tuning and amplification module 100 may include multiple sub-units such as a passive filtering unit 110, a multi-speed pre-attenuator 120, a tuning circuit 130 and a tuning amplifier 140, which achieve accurate preprocessing of low-frequency electromagnetic input signals through precise connection and coordination.

[0030] The passive filter unit 110 is responsible for filtering out interference signals outside the preset bandwidth range in the low-frequency electromagnetic input signal. These interference signals may come from environmental noise, electromagnetic interference, etc., which will seriously affect the quality and stability of the signal. The passive filter unit 110 can effectively remove these interference components through its internal filtering circuit, providing a clear and pure signal source for subsequent signal processing.

[0031] The multi-stage pre-attenuator 120 is responsible for selecting an appropriate attenuation stage to attenuate the low-frequency electromagnetic input signal after passive filtering according to the attenuation control signal sent by the main control module 400, in order to adjust the amplitude of the signal so that it can meet the processing requirements of the subsequent tuning circuit 130 and the tuning amplifier 140. The multi-stage pre-attenuator 120 provides multiple attenuation stages, which can be selected according to the strength of the signal, thereby ensuring that the signal will not damage the circuit due to excessive amplitude during processing, nor will it be difficult to detect due to too small amplitude.

[0032] The tuning circuit 130 is the core part of the tuning amplifier module 100, which is responsible for tuning the low-frequency electromagnetic input signal in the preset frequency range after attenuation according to the tuning control signal sent by the main control module 400. The tuning circuit 130 can change the frequency characteristics of the signal by adjusting the parameters of its internal inductance, capacitance and other components to match the processing requirements of the subsequent circuit, thereby ensuring the stability and accuracy of the signal during transmission and processing.

[0033] The tuned amplifier 140 is responsible for amplifying the tuned low-frequency electromagnetic input signal to obtain a low-frequency electromagnetic transition signal. The tuned amplifier 140 can significantly enhance the amplitude of the signal through its internal amplification circuit, providing sufficient signal strength for subsequent signal processing. At the same time, the tuned amplifier 140 also has good linearity and stability, which can ensure that the signal will not be distorted or deformed during the amplification process.

[0034] In a specific embodiment of the present invention, the passive filtering bandwidth is 10kHz-100kHz, and is composed of a 10kHz high-pass filter and a 100kHz low-pass filter, mainly for filtering out industrial interference below 10kHz and radio interference above 100kHz.

[0035] The multi-level pre-attenuator 120 is composed of 0dB, 10dB, 20dB attenuators and switching relays. Under the control of the main control module 400, it can form four-level attenuation values ​​of 0dB, 10dB, 20dB and 30dB. The attenuation step value is 10dB. Its main function is to provide attenuation in the case of strong signals to prevent pre-amplification and subsequent amplification saturation. The pre-amplification 40dB amplification gain reduces the background noise requirement of the frequency conversion amplification module 200.

[0036] See also Figure 3 , Figure 3 This is a circuit diagram of an embodiment of a tuning circuit provided by the present invention. In some embodiments of the present invention, the tuning circuit 130 includes a plurality of inductors connected in series and a plurality of capacitors connected in parallel.

[0037] In the above embodiment, the tuning circuit 130 is composed of a tuning inductor divided into n grades and a tuning capacitor divided into m grades. The tuning inductor and the tuning capacitor are LC tuned in series. By selecting untuned inductors and tuning capacitors to form different tuning frequencies covering 10kHz-100kHz, for the frequency of 10kHz-100kHz, the tuning frequency is divided into 5 segments, so the tuning inductor grade value n is taken as 5, and the frequency span of each grade does not exceed 1.6 times. The 5-grade tuning frequency ranges are 10kHz-16kHz, 16kHz, and 16kHz, respectively. -25kHz, 25kHz-40kHz, 40kHz-64kHz, 64kHz-102kHz, the tuning circuit 130Q value is about 6, the tuning bandwidth is about 1.5kHz at the lowest frequency 10kHz, and the tuning bandwidth is about 15kHz at the highest frequency 100kHz, which can preliminarily filter out out-of-band interference; the tuning amplifier filter has basically no suppression ability for deviations from the operating frequency of 600Hz, and is used to suppress interference at the far end of the operating frequency to make up for the insufficient suppression of the narrow-band crystal filter at the far end of the operating frequency.

[0038] The bin capacitor is a binary capacitor. When m is 8, the parallel capacitance values ​​of the basic capacitor C0 are C, 2C, 4C, 8C, 16C, 32C, 64C and 128C, respectively. According to the binary combination, 256 capacitance values ​​can be formed. Therefore, each tuning frequency range can be subdivided into 256 types under the bin tuning capacitor. The 5-band tuning frequency has a total of 256*5 and a total of 1280 tuning frequency points. The highest frequency tuning frequency is about 125Hz interval, and the lowest tuning frequency is about 25Hz interval. The minimum tuning step is about 1 / 80 of the tuning bandwidth, and the tuning step is fine enough.

[0039] See also Figure 4 , Figure 4 A structural diagram of an embodiment of a tuned amplifier provided by the present invention. In some embodiments of the present invention, the tuned amplifier 140 further includes: a matching transformer 141, a low noise amplifier 142 and a first effective value detection circuit 143; the matching transformer 141, the low noise amplifier 142 and the first effective value detection circuit 143 are connected in sequence; the first effective value detection circuit 143 is also connected to the main control module 400; The matching transformer 141 is used to amplify the tuned low-frequency electromagnetic input signal according to a preset magnification; The low noise amplifier 142 is used to perform low noise amplification processing on the low frequency electromagnetic input signal after amplification by a preset magnification to obtain a low frequency electromagnetic transition signal; The first effective value detection circuit 143 is used to input the low-frequency electromagnetic transient signal to the main control module 400 to determine whether the signal is saturated.

[0040] In the above embodiment, the tuned amplifier 140 is composed of a matching transformer 141, a two-stage low noise amplifier 142 and an effective value detection circuit. The gain of the tuned amplifier 140 is 40dB, and the transformation ratio of the matching transformer 141 is 2-3. The output signal of the tuned circuit 130 is amplified by 2-3 times, and the background noise requirement of the tuned amplifier 140 is reduced. The low noise amplifier 142 is designed to adopt the OPA2211 low noise amplifier 142, which has an input noise of 1.1nV / Hz1 / 2 at 1kHz-100kHz. The input end is connected in parallel with diodes D1 and D2 to provide a discharge circuit for large signals to prevent damage to the OPA2211 low noise amplifier 142. The effective value detection circuit sends the output of the tuned amplifier 140 to the main control module 400 to determine whether the signal is saturated. When the tuned amplifier 140 is saturated, the main control module 400 controls the controllable pre-attenuation to increase the attenuation until the tuned amplifier 140 is not saturated.

[0041] OPA2211 low noise amplifier 142 indicators: 1) Noise voltage: 1.1nV / Hz 1 / 2 (1kHz-100kHz); 2) Noise current: 1.7pA / Hz 1 / 2 (1kHz-100kHz); 3) Gain bandwidth: 80MHz; 4) Input impedance: 20kΩ (differential), 1GΩ (common mode).

[0042] See also Figure 5 , Figure 5 The structure diagram of an embodiment of the frequency conversion amplification module provided by the present invention, in some embodiments of the present invention, the frequency conversion amplification module 200 further includes: a mixing circuit 210, a first narrow-band crystal filter 220, a first automatic gain control circuit 230, a second narrow-band crystal filter 240, a second automatic gain control circuit 250, a differential amplifier 260 and a second effective value detection circuit 270; the mixing circuit 210, the first narrow-band crystal filter 220, the first automatic gain control circuit 230, the second narrow-band crystal filter 240, the second automatic gain control circuit 250, the differential amplifier 260 and the second effective value detection circuit 270 are connected in sequence; the mixing circuit 210 is also connected to the signal processing module 300; the second effective value detection circuit 270 is also connected to the main control module 400; The mixing circuit 210 is used to mix the local oscillator signal sent by the signal processing module 300 with the low-frequency electromagnetic transition signal to obtain a mixed signal; The first narrowband crystal filter 220 and the second narrowband crystal filter 240 are used to perform narrowband filtering on the mixed signal; The first automatic gain control circuit 230 and the second automatic gain control circuit 250 are used to adjust the amplification gain to amplify the mixed signal; The differential amplifier 260 is used to perform differential amplification processing on the amplified mixed signal to obtain an intermediate frequency electromagnetic signal; The second effective value detection circuit 270 is used to input the intermediate frequency electromagnetic signal to the main control module 400 to determine whether the signal is saturated.

[0043] In the above embodiment, the mixer circuit 210 is responsible for mixing the local oscillator signal sent by the signal processing module 300 with the low-frequency electromagnetic transition signal output by the tuning and amplification module 100, and its purpose is to convert the frequency of the low-frequency electromagnetic transition signal to a frequency band more suitable for subsequent processing, that is, an intermediate frequency band. The mixer circuit 210 realizes the frequency conversion of the signal through its internal nonlinear elements, such as diodes or transistors, and outputs a mixed signal containing the required intermediate frequency signal.

[0044] The first narrowband crystal filter 220 and the second narrowband crystal filter 240 are responsible for narrowband filtering of the mixed signal. The two filters can selectively pass signals within a specific frequency range through their internal crystal resonators, while suppressing signals of other frequencies, further removing interference components in the mixed signal and improving the purity and stability of the signal. At the same time, the first narrowband crystal filter 220 and the second narrowband crystal filter 240 can also be cascaded as needed to provide a deeper filtering effect and a narrower bandwidth.

[0045] The first automatic gain control circuit 230 and the second automatic gain control circuit 250 are used to adjust the amplification gain to amplify the mixed signal. The two automatic gain control circuits monitor the amplitude of the input signal in real time and adjust the gain of the amplifier as needed to ensure that the amplitude of the output signal remains within a certain range. This not only avoids damage to the circuit due to excessive amplitude of the signal, but also ensures the stability and accuracy of the signal in subsequent processing.

[0046] The differential amplifier 260 is responsible for differentially amplifying the amplified mixed signal to obtain an intermediate frequency electromagnetic signal. The differential amplifier 260 can significantly improve the anti-interference ability and stability of the signal through its internal differential amplification circuit, providing a clearer and more stable signal source for subsequent signal processing.

[0047] The second effective value detection circuit 270 is used to input the intermediate frequency electromagnetic signal into the main control module 400 to determine whether the signal is saturated. This is achieved by real-time monitoring of the amplitude of the intermediate frequency electromagnetic signal. When the signal amplitude exceeds a certain threshold, the second effective value detection circuit 270 will send a saturation signal to the main control module 400, prompting the system to take corresponding protection measures to avoid circuit damage or performance degradation due to signal saturation.

[0048] In a specific embodiment of the present invention, the first automatic gain control circuit 230 and the second automatic gain control circuit 250 have a total amplification gain of 96 dB, and a second narrowband crystal filter 240 is inserted in between, so that the 96 dB gain of the first automatic gain control circuit 230 and the second automatic gain control circuit 250 is divided into two separate 48 dB gains, and the amplification is stable and does not self-excite.

[0049] The mixer circuit 210 mixes the input signal of the tuned amplifier module 100 with the local oscillator Lo, filters out-of-band interference through narrowband crystal filter 1 and narrowband crystal filter 2, and extracts the 198kHz intermediate frequency signal IF. The 198kHz intermediate frequency is selected mainly based on the comprehensive consideration of the bandwidth and size of the narrowband crystal filter, 60mm (length) * 30mm (width) * 26mm (height).

[0050] The mixer circuit 210 is designed to use an active double-balanced mixer, with an operating frequency range of 10kHz to 100kHz, a large dynamic range, and low mixing distortion (even harmonics of the signal are offset, especially the second harmonic, so the interference of the output combination frequency is greatly reduced). At the same time, the impedance of the active mixer circuit 210 is easy to match, and each port has a high degree of isolation.

[0051] The 3dB bandwidth of the first narrowband crystal filter 220 and the second narrowband crystal filter 240 are both 480Hz, and the 3dB bandwidth of the first narrowband crystal filter 220 and the second narrowband crystal filter 240 after being cascaded is 400Hz. The suppression capability of each narrowband crystal filter deviating from 600Hz is 30dB, and the cascade of two narrowband crystal filters has a suppression capability of more than 60dB for signals deviating from the center frequency of 600Hz. The narrowband filter steepness system is not greater than 3, which can suppress out-of-band interference in the case of strong electromagnetic interference and effectively receive communication signals.

[0052] The main technical indicators of narrowband crystal filters are as follows: 1) Center frequency: 198kHz; 2) 3dB passband bandwidth: 480Hz; 3) 30dB stopband bandwidth: ±600Hz; 4) Insertion loss: 3dB; 5) Input and output impedance: 1kΩ.

[0053] The first automatic gain control circuit 230 and the second automatic gain control circuit 250 use AD604 as a low-noise dual-channel variable gain amplifier, and both channels have an automatic adjustable gain of 0-48dB; the differential amplifier has a gain of 6dB, and the first automatic gain control circuit 230, the second automatic gain control circuit 250 and the differential amplifier have an adjustable gain of 6dB-102dB.

[0054] The differential output converts the single-ended output of the second automatic gain control circuit 250 into a differential output, thereby improving the anti-interference capability of the signal processing module 300. The effective value detection converts the AC signal output by the second automatic gain control circuit 250 into a DC signal for sampling by the main control module 400AD to determine the output amplitude of the frequency conversion amplifier module 200.

[0055] The main indicators of AD604 dual-channel variable gain amplifier are as follows: 1) Voltage noise: 0.8nV / Hz 1 / 2 ; 2) Current noise: 3.0PA / Hz 1 / 2 ; 3) Gain range: 0-48dB (per channel); 4) Bandwidth: 40MHz; 5) Input impedance: 300kΩ.

[0056] In some embodiments of the present invention, the first automatic gain control circuit 230 and the second automatic gain control circuit 250 are also connected to the main control module 400; the first automatic gain control circuit 230 transmits the first gain to the main control module 400; the second automatic gain control circuit 250 transmits the second gain to the main control module 400.

[0057] In the above embodiment, after completing the initial amplification of the mixing signal, the first automatic gain control circuit 230 transmits its current gain value (first gain) to the main control module 400. By receiving and processing this information, the main control module 400 can understand the gain of the mixing signal after the first stage of amplification, thereby fine-tuning or optimizing the gain of the entire system as needed.

[0058] Similarly, after completing further amplification of the signal, the second automatic gain control circuit 250 will also transmit its current gain value (second gain) to the main control module 400, which not only provides gain information of the mixed signal after the second stage amplification, but also provides the main control module 400 with comprehensive monitoring of the gain status of the entire system.

[0059] By real-time monitoring and recording the gain values ​​of these two automatic gain control circuits, the main control module 400 can more accurately control the gain state of the entire receiving device, thereby ensuring the stability and accuracy of the signal during the processing process, which not only improves the reliability and stability of the system, but also provides a clearer and more stable signal source for subsequent signal processing.

[0060] See also Figure 6 , Figure 6 The structure diagram of an embodiment of the signal processing module provided by the present invention, in some embodiments of the present invention, the signal processing module 300 further includes: an analog-to-digital converter 310, a local oscillator generation unit 320, a digital signal processor 330 and a field programmable gate array 340; the analog-to-digital converter 310, the field programmable gate array 340, the digital signal processor 330 and the local oscillator generation unit 320 are connected in sequence; The analog-to-digital converter 310 is used to convert the intermediate frequency electromagnetic signal into an intermediate frequency digital signal according to a preset clock signal and send it to the field programmable gate array 340; The field programmable gate array 340 is used to down-convert the intermediate frequency digital signal into a baseband signal, then digitally filter the baseband signal and transmit it to the digital signal processor 330, and decode the baseband signal demodulated by the digital signal processor 330 to obtain the target transmission signal; The digital signal processor 330 is used to synchronize and demodulate the filtered baseband signal and transmit it to the field programmable gate array 340; The local oscillator generating unit 320 is used to generate a local oscillator signal.

[0061] In the above embodiment, the analog-to-digital converter 310 (ADC) is responsible for converting the intermediate frequency electromagnetic signal output by the variable frequency amplification module 200 into a digital signal by sampling and quantizing the intermediate frequency electromagnetic signal according to a preset clock signal. The digital signal output by the analog-to-digital converter 310 has high precision and stability, providing a reliable basis for subsequent digital signal processing.

[0062] The field programmable gate array 340 (FPGA) is responsible for down-converting the intermediate frequency digital signal output by the analog-to-digital converter 310 and converting it into a baseband signal. The down-conversion process is achieved by mixing the intermediate frequency digital signal with the local oscillator signal generated inside the FPGA to obtain a low-frequency baseband signal. The FPGA also has powerful digital signal processing capabilities and can digitally filter the baseband signal to remove noise and interference components and improve the purity and stability of the signal. The filtered baseband signal is transmitted to the digital signal processor 330 for further synchronization and demodulation processing.

[0063] The digital signal processor 330 (DSP) is responsible for synchronizing and demodulating the filtered baseband signal transmitted from the FPGA. The synchronization process is to ensure that the phase and frequency of the signal are consistent with the transmitting end, while the demodulation process is to restore the modulation information in the baseband signal to the original information data. The demodulated baseband signal is retransmitted to the FPGA for decoding to obtain the final target transmission signal.

[0064] The local oscillator generation unit 320 (DDS) is responsible for generating the local oscillator signal, which is one of the indispensable key signals in the signal processing process. It is used to mix with the input signal to achieve the frequency conversion of the signal. The local oscillator generation unit 320 can generate a stable and accurate local oscillator signal through the internal oscillation circuit and frequency synthesis technology, providing a reliable frequency reference for the entire signal processing module 300.

[0065] In a specific embodiment of the present invention, the signal processing module 300 is based on an open hardware architecture of DDS+DSP+FPGA, is the main body for realizing the functions of the whole machine, and is also the main carrier of waveform operation. It can provide digital intermediate frequency capability and baseband signal processing capability, and mainly completes the waveform physical layer function. In order to meet the requirements of DDS output signal frequency accuracy, the DDS frequency control word is not less than 32 bits. At the same time, in order to ensure that the corresponding computing power is met, DSP selects TMS320C674× and FPGA selects XC7K325T.

[0066] The ADC main chip is AD7762 from Huawei, a 24-bit ADC. In this design, the sampling rate is 512kHz. A small module is made in the form of a stamp hole and soldered on the signal processing baseboard to facilitate the isolation between the digital ground and the analog ground. Its control, clock and data are connected to the FPGA. The DDS uses AD9851, a 32-bit frequency control word, which is used to generate the local oscillator Lo required for frequency conversion.

[0067] In some embodiments of the present invention, the signal processing module 300 further includes: a crystal oscillator 350; the crystal oscillator 350 is connected to the analog-to-digital converter 310; and the crystal oscillator 350 is used to generate a preset clock signal according to an external clock signal.

[0068] In the above embodiment, the crystal oscillator 350 is responsible for generating a preset clock signal according to the external clock signal. This preset clock signal is the basis for the analog-to-digital converter 310 to perform sampling and quantization, ensuring that the intermediate frequency electromagnetic signal can be accurately converted into a digital signal. The crystal oscillator 350 can generate a stable and accurate clock signal through the internal crystal resonator, providing a reliable timing reference for the entire signal processing module 300.

[0069] In some embodiments of the present invention, the signal processing module 300 includes a static random access memory 360 and a dynamic random access memory; the static random access memory 360 stores data and programs in the field programmable gate array 340 and the digital signal processor 330 by connecting to the field programmable gate array 340 and the digital signal processor 330; the dynamic random access memory 370 stores data and programs in the field programmable gate array 340 and the digital signal processor 330 by connecting to the field programmable gate array 340 and the digital signal processor 330.

[0070] In the above embodiment, the static random access memory 360 (SRAM) realizes the storage of data and programs in the field programmable gate array 340 (FPGA) and the digital signal processor 330 (DSP) by connecting to the two components. SRAM has the characteristics of high-speed reading and writing and maintaining data stability. Even after power failure, the stored data will not be lost (but it should be noted that data protection still needs to be considered in the case of long-term power failure or extreme conditions). This makes SRAM an ideal choice for storing key data and programs required for the operation of FPGA and DSP, ensuring the stability and reliability of the signal processing module 300.

[0071] Dynamic random access memory 370 (DRAM) is also a storage component in the signal processing module 300. It also stores data and programs in the two components through connection with FPGA and DSP. Although DRAM will lose data after power failure, it has a large storage capacity and relatively low cost, so it is often used to store a large amount of temporary data and programs. In the signal processing process, DRAM can be used as a data buffer and temporary storage space during program execution to improve the processing speed and efficiency of the system.

[0072] In some embodiments of the present invention, the main control module 400 includes a central processing unit; the central processing unit is used to generate a variety of control signals and control the tuning and amplification module 100, the frequency conversion amplification module 200, and the signal processing module 300 through the I / O bus.

[0073] In the above embodiments, the central processing unit (CPU) can efficiently execute various complex calculation and control tasks through the built-in instruction set and operation unit. In the high-sensitivity, large-dynamic, anti-interference low-frequency receiving device, the CPU is not only responsible for receiving and processing signals or instructions from the outside, but also dynamically adjusts the working parameters and modes of each module according to the operating status and requirements of the system.

[0074] The I / O bus is responsible for transmitting the control signals generated by the CPU and the data and information between the modules. The I / O bus is high-speed, reliable and flexible, and can ensure real-time communication and data exchange between the CPU and other modules. Through the I / O bus, the CPU can accurately control the working state of the tuning and amplification module 100, the frequency conversion amplification module 200 and the signal processing module 300, such as adjusting the gain, changing the frequency, starting or stopping the processing, etc.

[0075] In a specific embodiment of the present invention, the indicators of the main control module 400 are as follows: 1) Using ZYNQ7020 processor; 2) Onboard 1 32GB EMMC; 3) Provide 5 10M / 100M / 1000Mbps adaptive Ethernet interfaces; 4) Provide 6 RS232 interfaces and 1 RS422 interface; 5) Provide 40 GPIO interfaces; 6) Provide 2-way AD sampling interface and 2-way DA interface; 7) Provide 3 clock output interfaces.

[0076] The main functions are as follows: 1) Responsible for tuning and amplifying the tuning and amplifying module 100 to perform effective value detection AD sampling, control the controllable pre-attenuation, and ensure that the tuning and amplifying output signal is not saturated and is within the linear range; 2) Responsible for tuning the frequency control of the tuning amplifier module 100 and controlling the signal processing module 300 to generate a suitable local oscillator signal; 3) Perform AD sampling on the effective value detection of the frequency conversion amplifier module 200, adjust the controllable attenuation value of the tuning amplifier module 100 according to the gains of the two, control the gain of the whole machine, and make the tuning amplifier module 100 unsaturated; 4) Receive information from the signal processing module 300 and exchange information with the outside world through the network.

[0077] In summary, the present invention provides a high-sensitivity, large-dynamic, anti-interference low-frequency receiving device, which can respond to the control signal of the main control module 400 through the tuning and amplification module 100, and perform denoising and amplification processing on the low-frequency electromagnetic input signal, which can effectively remove the noise component in the signal, enhance the strength of the signal, and provide high-quality input for subsequent signal processing. After the frequency conversion amplification module 200 performs frequency conversion processing on the low-frequency electromagnetic transition signal, it performs narrowband filtering processing and differential amplification processing to obtain an intermediate frequency electromagnetic signal, which not only converts the signal frequency to a frequency band more suitable for processing, but also further removes noise and interference through narrowband filtering, thereby improving the purity and stability of the signal. The signal processing module 300 synchronizes, demodulates and decodes the intermediate frequency electromagnetic signal to obtain the target transmission signal, ensuring the accurate reception and analysis of the signal, and providing a reliable basis for subsequent data processing and analysis. The modular design is adopted to separate the functional modules such as tuning amplification, frequency conversion amplification, signal processing and main control, so that each module can work independently without affecting each other, which is convenient for maintenance and maintenance.

[0078] It should be noted that, for the aforementioned method embodiments, for the sake of simplicity, they are all expressed as a series of action combinations, but those skilled in the art should be aware that the present application is not limited by the described order of actions, because according to the present application, certain steps can be performed in other orders or simultaneously. Secondly, those skilled in the art should also be aware that the embodiments described in the specification are all preferred embodiments, and the actions and modules involved are not necessarily required by the present application.

[0079] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0080] In the several embodiments provided in the present application, it should be understood that the disclosed devices can be implemented in other ways. For example, the device embodiments described above are only schematic, such as the division of the units, which is only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some service interfaces, and the indirect coupling or communication connection of devices or units can be electrical or other forms.

[0081] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0082] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0083] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable memory. Based on this understanding, the technical solution of the present application, or the part that contributes to the prior art, or all or part of the technical solution can be embodied in the form of a software product. The computer software product is stored in a memory, including a number of instructions to enable a computer device (which can be a personal computer, server or network device, etc.) to execute all or part of the steps of the method described in each embodiment of the present application. The aforementioned memory includes: U disk, read-only memory (ROM), random access memory (RAM), mobile hard disk, disk or optical disk and other media that can store program codes.

[0084] A person skilled in the art may understand that all or part of the steps in the various methods of the above embodiments may be completed by instructing related hardware through a program, and the program may be stored in a computer-readable memory, which may include: a flash drive, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk, etc.

[0085] The above is only an exemplary embodiment of the present disclosure, and the scope of the present disclosure cannot be limited thereto. That is, any equivalent changes and modifications made according to the teachings of the present disclosure are still within the scope of the present disclosure. After considering the specification and practicing the disclosure here, those skilled in the art will easily think of the implementation scheme of the present disclosure. This application is intended to cover any modification, use or adaptation of the present disclosure, which follows the general principles of the present disclosure and includes common knowledge or customary technical means in the technical field not recorded in the present disclosure. The description and examples are regarded as exemplary only, and the scope and spirit of the present disclosure are defined by the claims.

[0086] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0087] It will be easily understood by those skilled in the art that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A high-sensitivity, large-dynamic, anti-interference low-frequency receiving device, characterized in that: include: A tuning and amplifying module, a frequency conversion amplifying module, a signal processing module and a main control module; the tuning and amplifying module, the frequency conversion amplifying module, the signal processing module and the main control module are connected in sequence; The tuning and amplification module is used to perform denoising and amplification processing on the low-frequency electromagnetic input signal in response to the first control signal of the main control module to obtain a low-frequency electromagnetic transition signal; The frequency conversion and amplification module is used to respond to the second control signal of the main control module to perform frequency conversion processing on the low-frequency electromagnetic transition signal, and then perform narrow-band filtering processing and differential amplification processing to obtain an intermediate frequency electromagnetic signal; The signal processing module is used to synchronize, demodulate and decode the intermediate frequency electromagnetic signal in response to the third control signal of the main control module to obtain a target transmission signal; The main control module is used to generate the first control signal, the second control signal and the third control signal, and receive the target transmission signal.

2. The high-sensitivity, large-dynamic, anti-interference low-frequency receiving device according to claim 1, characterized in that: The first control signal includes an attenuation control signal and a tuning control signal; The tuning and amplification module further includes: a passive filtering unit, a multi-stage pre-attenuator, a tuning circuit and a tuning amplifier; the passive filtering unit, the multi-stage pre-attenuator, the tuning circuit and the tuning amplifier are connected in sequence; Wherein, the passive filtering unit is used to filter out interference signals outside a preset bandwidth range in the low-frequency electromagnetic input signal; The multi-stage pre-attenuator is used to select the attenuation stage according to the attenuation control signal to attenuate the low-frequency electromagnetic input signal after passive filtering; The tuning circuit is used to perform tuning processing on the attenuated low-frequency electromagnetic input signal within a preset frequency range according to the tuning control signal; The tuned amplifier is used to amplify the tuned low-frequency electromagnetic input signal to obtain the low-frequency electromagnetic transition signal.

3. The high-sensitivity, large-dynamic, anti-interference low-frequency receiving device according to claim 2, characterized in that: The tuning circuit includes a plurality of inductors connected in series and a plurality of capacitors connected in parallel.

4. The high-sensitivity, large-dynamic, anti-interference low-frequency receiving device according to claim 2, characterized in that: The tuned amplifier further comprises: a matching transformer, a low noise amplifier and a first effective value detection circuit; the matching transformer, the low noise amplifier and the first effective value detection circuit are connected in sequence; the first effective value detection circuit is also connected to the main control module; Wherein, the matching transformer is used to amplify the tuned low-frequency electromagnetic input signal according to a preset magnification; The low-noise amplifier is used to perform low-noise amplification processing on the low-frequency electromagnetic input signal after amplification by the preset magnification to obtain the low-frequency electromagnetic transition signal; The first effective value detection circuit is used to input the low-frequency electromagnetic transient signal into the main control module to determine whether the signal is saturated.

5. The high-sensitivity, large-dynamic, anti-interference low-frequency receiving device according to claim 1, characterized in that: The variable frequency amplification module further includes: a frequency mixing circuit, a first narrowband crystal filter, a first automatic gain control circuit, a second narrowband crystal filter, a second automatic gain control circuit, a differential amplifier and a second effective value detection circuit; the frequency mixing circuit, the first narrowband crystal filter, the first automatic gain control circuit, the second narrowband crystal filter, the second automatic gain control circuit, the differential amplifier and the second effective value detection circuit are connected in sequence; the frequency mixing circuit is also connected to the signal processing module; the second effective value detection circuit is also connected to the main control module; Wherein, the mixing circuit is used to mix the local oscillator signal sent by the signal processing module with the low-frequency electromagnetic transition signal to obtain a mixed signal; The first narrowband crystal filter and the second narrowband crystal filter are used to perform narrowband filtering on the mixed signal; The first automatic gain control circuit and the second automatic gain control circuit are used to adjust the amplification gain to amplify the mixed signal; The differential amplifier is used to perform differential amplification processing on the amplified mixed signal to obtain the intermediate frequency electromagnetic signal; The second effective value detection circuit is used to input the intermediate frequency electromagnetic signal into the main control module to determine whether the signal is saturated.

6. The high-sensitivity, large-dynamic, anti-interference low-frequency receiving device as claimed in claim 5, characterized in that: The first automatic gain control circuit and the second automatic gain control circuit are also connected to the main control module; the first automatic gain control circuit transmits the first gain to the main control module; the second automatic gain control circuit transmits the second gain to the main control module.

7. The high-sensitivity, large-dynamic, anti-interference low-frequency receiving device according to claim 5, characterized in that: The signal processing module further comprises: an analog-to-digital converter, a local oscillator generating unit, a digital signal processor and a field programmable gate array; the analog-to-digital converter, the field programmable gate array, the digital signal processor and the local oscillator generating unit are connected in sequence; Wherein, the analog-to-digital converter is used to convert the intermediate frequency electromagnetic signal into an intermediate frequency digital signal according to a preset clock signal and send it to the field programmable gate array; The field programmable gate array is used to down-convert the intermediate frequency digital signal into a baseband signal, then digitally filter the baseband signal and transmit it to the digital signal processor, and decode the baseband signal demodulated by the digital signal processor to obtain a target transmission signal; The digital signal processor is used to synchronize and demodulate the filtered baseband signal and transmit it to the field programmable gate array; The local oscillator generating unit is used to generate the local oscillator signal.

8. The high-sensitivity, large-dynamic, anti-interference low-frequency receiving device according to claim 7, characterized in that: The signal processing module also includes: a crystal oscillator; the crystal oscillator is connected to the analog-to-digital converter; the crystal oscillator is used to generate the preset clock signal according to an external clock signal.

9. The high-sensitivity, large-dynamic, anti-interference low-frequency receiving device according to claim 7, characterized in that: The signal processing module includes a static random access memory and a dynamic random access memory; the static random access memory is connected to the field programmable gate array and the digital signal processor to store data and programs in the field programmable gate array and the digital signal processor; the dynamic random access memory is connected to the field programmable gate array and the digital signal processor to store data and programs in the field programmable gate array and the digital signal processor.

10. The high-sensitivity, large-dynamic, anti-interference low-frequency receiving device according to claim 1, characterized in that: The main control module includes a central processing unit; the central processing unit is used to generate a variety of control signals and control the tuning and amplification module and the signal processing module through an I / O bus.

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