Airborne electromagnetic emission current measurement system

Abstract

The present application relates to the field of airborne electromagnetic measurement technology, and specifically to an airborne electromagnetic emission current measurement system, comprising a transmitting coil, a non-inductive shunt, a signal conversion circuit, a signal amplification circuit, and a signal output circuit. The non-inductive shunt is connected to the transmitting coil and is used to convert the current flowing through the transmitting coil into a voltage signal; the signal conversion circuit is used to perform proportional feedback processing on the voltage signal and generate a proportional feedback signal; the signal amplification circuit is used to amplify the proportional feedback signal and generate an amplified analog signal; the signal output circuit is used to perform analog-to-digital conversion on the amplified analog signal and generate a digital signal. The present application is based on direct measurement using the non-inductive shunt, directly generating a voltage drop through a resistor. The signal delay is only affected by circuit parasitic parameters, resulting in a short response time, higher measurement accuracy, and a smaller overall size. It is suitable for airborne electromagnetic emission current detection.

Description

Technical Field

[0001] The present application relates to the technical field of airborne electromagnetic measurement, and in particular to an airborne electromagnetic emission current measurement system. Background Art

[0002] In airborne electromagnetic detection systems, accurate measurement of emission current is crucial for obtaining effective Earth physics information. Existing current transformers and traditional shunts suffer from slow response, large nonlinear errors, and low accuracy under high-frequency pulse conditions, making them unable to meet the stringent emission current measurement accuracy requirements required during high-altitude flight.

[0003] Utility model patent CN217133260U, issued on August 5, 2022, discloses a kiloampere-level transmission current peak detection circuit for airborne electromagnetic transmitters. The circuit includes a current sensor, an absolute value circuit, a peak sampling and holding circuit, a peak sampling synchronous pulse generation circuit, and a digital DC voltmeter. However, the circuit suffers from issues such as Hall effect sensors being sensitive to electromagnetic interference, poor linear output, and low accuracy.

[0004] Patent publication number CN116735974A, published on September 12, 2023, discloses a high-current, high-precision loop resistance measurement device and method. The device includes a voltage acquisition module, a current sampling analog operation module, a first current sampling module, a second current sampling module, a voltage amplification module, a switch drive module, a supercapacitor charging module, a supercapacitor, a switch module, a voltage test line, a current test line, and a battery pack. The device utilizes a supercapacitor to create a high-current pulsed DC source. However, due to its cumbersome structure and the large space occupied by the overall structure, it is not suitable for airborne electromagnetic emission current detection.

[0005] Therefore, it is urgent to design an airborne electromagnetic emission current measurement system. Summary of the Invention

[0006] Based on this, it is necessary to provide an airborne electromagnetic emission current measurement system that can realize direct measurement based on a non-inductive shunt, suitable for high-frequency transient current detection to obtain the magnitude of the emission current in the circuit, with higher measurement accuracy, and at the same time solve the problem in the existing technology that the non-contact measurement method is used, which requires magnetic field conversion and signal processing, resulting in slow response speed.

[0007] The technical solutions of the present invention are as follows:

[0008] An airborne electromagnetic emission current measurement system includes a transmitting coil and further includes:

[0009] a non-inductive shunt, connected to the transmitting coil and configured to convert the current flowing through the transmitting coil into a voltage signal;

[0010] a signal conversion circuit, connected to the non-inductive shunt, for performing proportional feedback processing on the voltage signal and generating a proportional feedback signal;

[0011] a signal amplifying circuit, connected to the signal converting circuit, for amplifying the proportional feedback signal and generating an amplified analog signal;

[0012] The signal output circuit and the signal amplification circuit are used to perform analog-to-digital conversion on the amplified analog signal and generate a digital signal.

[0013] Optionally, the non-inductive shunt is connected in series with the transmitting coil.

[0014] Optionally, the signal conversion circuit includes a proportional feedback processing circuit and a gain amplification circuit, the proportional feedback processing circuit is connected to the non-inductive shunt, the gain amplification circuit is connected to the proportional feedback processing circuit, and the gain amplification circuit is also connected to the signal amplification circuit; the proportional feedback processing circuit is used to proportionally feedback amplify the voltage signal, and the gain amplification circuit is used to gain amplify the voltage signal after proportional feedback amplification and generate the proportional feedback signal.

[0015] Optionally, the proportional feedback processing circuit includes a first amplifier, a second amplifier, a first resistor, a second resistor and a third resistor; the positive input terminal of the first amplifier is connected to the second resistor and then to the shunt, the positive input terminal of the second amplifier is connected to the shunt, the first resistor is connected to the negative input terminal of the first amplifier and then to ground, the third resistor is connected to the negative input terminal of the first amplifier and then to the gain amplifier circuit; the output terminals of the first amplifier and the second amplifier are both connected to the gain amplifier circuit.

[0016] Optionally, the gain amplifier circuit includes a fourth resistor, a fifth resistor, a third amplifier and a ninth resistor, the first end of the fourth resistor is connected to the output end of the first amplifier, the first end of the fifth resistor is connected to the output end of the second amplifier, the second end of the fourth resistor is connected to the second end of the fifth resistor, the second end of the fourth resistor is also connected to the negative input end of the third amplifier, the ninth resistor is connected to the positive input end of the third amplifier, and the output end of the third amplifier is connected to the signal amplifier circuit.

[0017] Optionally, the signal amplification circuit includes a sixth resistor, a seventh resistor, a fourth amplifier and a fifth amplifier, the first end of the sixth resistor is connected to the output end of the third amplifier, the other end of the sixth resistor is connected to the negative input end of the fourth amplifier, the seventh resistor is connected to the positive input end of the fourth amplifier and then grounded, the positive input end of the fifth amplifier is connected to the output end of the fourth amplifier, and the output end of the fifth amplifier is connected to the signal output circuit.

[0018] Optionally, the signal output circuit includes a receiver, a signal acquisition card is provided in the receiver, the signal acquisition card is connected to the output end of the fifth amplifier, and is used to convert the signal output from the output end of the fifth amplifier into a digital signal.

[0019] Optionally, a filtering circuit is also included, which includes a filtering capacitor, a first end of the filtering capacitor is connected to the shunt and the positive input end of the first amplifier, and a second end of the filtering capacitor is connected to the shunt and the positive input end of the second amplifier.

[0020] The present invention achieves the following technical effects:

[0021] The above-mentioned airborne electromagnetic emission current measurement system is provided with a transmitting coil, a non-inductive shunt, a signal conversion circuit, a signal amplification circuit and a signal output circuit. The current flowing through the transmitting coil is converted into a voltage signal by the non-inductive shunt. Then, the signal conversion circuit performs proportional feedback processing on the voltage signal and generates a proportional feedback signal. Then, the signal amplification circuit amplifies the proportional feedback signal and generates an amplified analog signal. Finally, the signal output circuit performs analog-to-digital conversion on the amplified analog signal and generates a digital signal. Direct measurement based on the non-inductive shunt is achieved, and a voltage drop is directly generated through a resistor. The signal delay is only affected by circuit parasitic parameters. The response time can reach nanoseconds, which is suitable for high-frequency transient current detection to obtain the size of the emission current in the circuit, with higher measurement accuracy, solving the problem of slow response speed caused by the need for magnetic field conversion and signal processing due to the use of non-contact measurement methods in the prior art. In addition, the non-inductive shunt is connected to the transmitting coil, the signal conversion circuit and the signal amplification circuit can be integrated on a small PCB board, and the signal output circuit is a receiver, so that the rear stage of the non-inductive shunt is connected to a small PCB board, and the output signal is directly connected to the receiver, thereby making the overall volume of the airborne electromagnetic emission current measurement system smaller, which is suitable for airborne electromagnetic emission current detection. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 A circuit structure block diagram of an airborne electromagnetic emission current measurement system in one embodiment;

[0023] Figure 2 is a circuit schematic diagram of an airborne electromagnetic emission current measurement system in one embodiment;

[0024] Figure 3 A waveform diagram of an output signal obtained by simulation after inputting a test current signal into an airborne electromagnetic emission current measurement system in one embodiment;

[0025] Figure 4 This is an output waveform diagram of an airborne electromagnetic emission current measurement system in an embodiment of the present invention, when the temperature is controlled constant and no input is maintained in a laboratory incubator;

[0026] Figure 5 A diagram showing the linear error test results of an airborne electromagnetic emission current measurement system in one embodiment;

[0027] Figure 6 1 is a graph showing the test results of the temperature drift coefficient of an airborne electromagnetic emission current measurement system in one embodiment.

[0028] Reference numerals:

[0029] 100, signal conversion circuit; 110, proportional feedback processing circuit; 120, gain amplifier circuit; 200, signal amplifier circuit; 300, signal output circuit; 400, receiver; 500, filter circuit. DETAILED DESCRIPTION

[0030] To facilitate understanding of the present application, the present application will be described more fully below with reference to the accompanying drawings. The accompanying drawings provide embodiments of the present application. However, the present application may be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to make the disclosure of the present application more thorough and comprehensive.

[0031] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application pertains. The terms used herein in the specification of this application are for the purpose of describing specific embodiments only and are not intended to limit this application.

[0032] It will be understood that the terms "first," "second," etc., used herein may be used to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish a first element from another element. For example, a first resistor may be referred to as a second resistor, and similarly, a second resistor may be referred to as a first resistor without departing from the scope of this application. The first resistor and the second resistor are both resistors, but they are not the same resistor.

[0033] It can be understood that the “connection” in the following embodiments should be understood as “electrical connection”, “communication connection”, etc. if there is transmission of electrical signals or data between the connected circuits, modules, units, etc.

[0034] As used herein, the singular forms "a," "an," and "the" may also include the plural forms, unless the context clearly indicates otherwise. It should also be understood that the terms "include / comprise," "have," and the like specify the presence of stated features, integers, steps, operations, components, parts, or combinations thereof, but do not preclude the presence or addition of one or more other features, integers, steps, operations, components, parts, or combinations thereof. Furthermore, the term "and / or" as used in this specification includes any and all combinations of the relevant listed items.

[0035] In one embodiment, Figure 1-Figure 2 As shown, an airborne electromagnetic emission current measurement system is provided, which includes a transmitting coil, a non-inductive shunt, a signal conversion circuit 100 , a signal amplification circuit 200 and a signal output circuit 300 .

[0036] The non-inductive shunt is connected to the transmitting coil and is used to convert the current flowing through the transmitting coil into a voltage signal; the signal conversion circuit 100 is connected to the non-inductive shunt and is used to perform proportional feedback processing on the voltage signal and generate a proportional feedback signal; the signal amplification circuit 200 is connected to the signal conversion circuit 100 and is used to amplify the proportional feedback signal and generate an amplified analog signal; the signal output circuit 300 is connected to the signal amplification circuit 200 and is used to perform analog-to-digital conversion on the amplified analog signal and generate a digital signal.

[0037] In this embodiment, a transmitting coil, a non-inductive shunt, a signal conversion circuit 100, a signal amplification circuit 200, and a signal output circuit 300 are provided. The non-inductive shunt converts the current flowing through the transmitting coil into a voltage signal. Then, the signal conversion circuit 100 performs proportional feedback processing on the voltage signal and generates a proportional feedback signal. Then, the signal amplification circuit 200 amplifies the proportional feedback signal and generates an amplified analog signal. Finally, the signal output circuit 300 performs analog-to-digital conversion on the amplified analog signal and generates a digital signal. Direct measurement based on the non-inductive shunt is achieved, and a voltage drop is directly generated through a resistor. The signal delay is only affected by circuit parasitic parameters, and the response is accurate. The time can reach nanoseconds, which is suitable for high-frequency transient current detection to obtain the size of the emission current in the circuit, with higher measurement accuracy, solving the problem of slow response speed caused by the use of non-contact measurement methods in the prior art, which requires magnetic field conversion and signal processing. In addition, the non-inductive shunt is connected to the transmitting coil, the signal conversion circuit 100 and the signal amplification circuit 200 can be integrated on a small PCB board, and the signal output circuit 300 is a receiver 400, so that the rear stage of the non-inductive shunt is connected to a small PCB board, and the output signal is directly connected to the receiver 400, thereby making the overall volume of the airborne electromagnetic emission current measurement system small, and suitable for airborne electromagnetic emission current detection.

[0038] In one embodiment, the non-inductive shunt is connected in series with the transmitting coil. In this embodiment, the non-inductive shunt is directly connected in series with the transmitting coil to collect the current signal from the transmitting coil. The optimized structural design of the non-inductive shunt eliminates the effects of parasitic inductance in conventional AC signals, which can cause voltage-current phase shift and waveform distortion.

[0039] In one embodiment, the signal conversion circuit 100 includes a proportional feedback processing circuit 110 and a gain amplifier circuit 120, wherein the proportional feedback processing circuit 110 is connected to the non-inductive shunt, and the gain amplifier circuit 120 is connected to the proportional feedback processing circuit 110, and the gain amplifier circuit 120 is also connected to the signal amplifier circuit 200; the proportional feedback processing circuit 110 is used to proportionally feedback amplify the voltage signal, and the gain amplifier circuit 120 is used to gain amplify the voltage signal after proportional feedback amplification and generate the proportional feedback signal.

[0040] In one embodiment, the proportional feedback processing circuit 110 includes a first amplifier U1, a second amplifier U2, a first resistor R1, a second resistor R2, and a third resistor R3; the positive input terminal of the first amplifier U1 is connected to the second resistor R2 and then to the shunt, the positive input terminal of the second amplifier U2 is connected to the shunt, the first resistor R1 is connected to the negative input terminal of the first amplifier U1 and then to ground, the third resistor R3 is connected to the negative input terminal of the first amplifier U1 and then to the gain amplifier circuit 120; the output terminals of the first amplifier U1 and the second amplifier U2 are both connected to the gain amplifier circuit 120.

[0041] The two ends of the non-inductive shunt are respectively connected to the first operational amplifier U1 and the second operational amplifier U2. The first amplifier U1 and the second amplifier U2 are both unidirectional amplifiers, which ensure a higher input impedance of the circuit. The high input impedance presents a high impedance state to high-frequency noise, which can effectively attenuate high-frequency interference from the power supply, ground line or electromagnetic radiation, and improve the system signal-to-noise ratio.

[0042] In one embodiment, the proportional feedback processing circuit 110 further includes a third capacitor C3, a fourth capacitor C4, a fifth capacitor C5, and a sixth capacitor C6. The third capacitor C3 and the fourth capacitor C4 are both connected to the first amplifier U1. The fifth capacitor C5 and the sixth capacitor C6 are both connected to the second amplifier U2. The third capacitor C3, the fourth capacitor C4, the fifth capacitor C5, and the sixth capacitor C6 serve as power supply filter capacitors to reduce interference caused by the power supply to the first amplifier U1 and the second amplifier U2.

[0043] Specifically, by setting a proportional feedback processing circuit with the first amplifier U1 and the second amplifier U2 as the core to perform proportional feedback processing, the voltages at both ends of the non-inductive shunt are in a fixed ratio, solving the problem of poor linearity caused by differential processing in the prior art.

[0044] In one embodiment, the gain amplifier circuit 120 includes a fourth resistor R4, a fifth resistor R5, a third amplifier U3 and a ninth resistor R9, wherein the first end of the fourth resistor R4 is connected to the output end of the first amplifier U1, the first end of the fifth resistor R5 is connected to the output end of the second amplifier U2, the second end of the fourth resistor R4 is connected to the second end of the fifth resistor R5, the second end of the fourth resistor R4 is also connected to the negative input end of the third amplifier U3, the ninth resistor R9 is connected to the positive input end of the third amplifier U3, and the output end of the third amplifier U3 is connected to the signal amplification circuit 200.

[0045] Furthermore, with GND in the circuit as a reference point, the voltage across the non-inductive shunt is a constant proportional value, and the specific relationship is as follows:

[0046] ,in, is the positive input voltage of the first amplifier U1, i.e., the upper terminal voltage of the non-inductive shunt, is the positive input voltage of the second amplifier U2, that is, the lower end voltage of the non-inductive shunt. Such a circuit structure design can greatly enhance the anti-interference ability of the circuit.

[0047] and Negative feedback between the two amplifiers inverts the output signal and feeds it back to the input, where it is superimposed on the original input signal to form a net input signal. Therefore, the amplified output depends primarily on the feedback ratio, rather than the characteristics of a single op amp or amplifier. Furthermore, the buffering provided by the first amplifier U1 minimizes the voltage drop at the shunt node. Furthermore, the system automatically adjusts the output to minimize deviations caused by amplifier non-idealities, temperature drift, and other factors.

[0048] In one embodiment, the gain amplifier circuit 120 further includes a second capacitor C2, a seventh capacitor C7, and an eighth capacitor C8. The first end of the second capacitor C2 is connected to the fifth resistor R5, and the second end of the second capacitor C2 is connected to the input end of the third amplifier U3. The second capacitor C2 serves as a phase compensation capacitor to prevent excessive oscillation in the circuit. The seventh capacitor C7 and the eighth capacitor C8 are used for filtering.

[0049] In one embodiment, the signal amplification circuit 200 includes a sixth resistor R6, a seventh resistor R7, an eighth resistor R8, a fourth amplifier U4 and a fifth amplifier U5, wherein a first end of the sixth resistor R6 is connected to the output end of the third amplifier U3, and the other end of the sixth resistor R6 is connected to the negative input end of the fourth amplifier U4, the seventh resistor R7 is connected to the positive input end of the fourth amplifier U4 and then grounded, the positive input end of the fifth amplifier U5 is connected to the output end of the fourth amplifier U4, the output end of the fifth amplifier U5 is connected to the signal output circuit 300, and the two ends of the eighth resistor R8 are respectively connected to the negative input end and the output end of the fourth amplifier U4.

[0050] In this embodiment, the fourth amplifier U4 serves as a signal amplification module and adopts reverse amplification. The reverse amplification circuit only has differential mode signal input. This structure effectively suppresses the influence of common mode interference (such as power supply noise and electromagnetic interference).

[0051] The circuit outputs to the NI USB-4431 acquisition card inside the receiver 400 in the signal output circuit 300. The cable distance is close to one meter. If the output current is insufficient, waveform distortion is likely to occur. The fifth amplifier U5 adopts a follower structure. The main purpose is to select an operational amplifier with high load capacity. At the same time, the output impedance of the same-direction amplifier is low, which further improves the load capacity and ensures the output power.

[0052] When selecting the first amplifier U1, the second amplifier U2, the third amplifier U3, and the fourth amplifier U4, attention should be paid to the bandwidth, and a suitable gain-bandwidth product should be calculated by a person skilled in the art. At the same time, an operational amplifier with a low offset voltage should be selected to ensure the overall sensitivity of the circuit. The first amplifier U1 and the second amplifier U2 should also pay extra attention to the size of the input impedance to ensure anti-interference capability.

[0053] The third resistor R3 and the first resistor R1 jointly control the amplification factor of the first amplifier U1, the sixth resistor R6 and the eighth resistor R8 jointly control the amplification factor of the fourth amplifier U4, and the fifth resistor R5 and the fourth resistor R4 jointly control the amplification factor of the third amplifier U3.

[0054] In one embodiment, the signal output circuit 300 includes a receiver 400, which includes a signal acquisition card. The signal acquisition card is connected to the output of the fifth amplifier U5 and is configured to convert the signal output from the output of the fifth amplifier U5 into a digital signal. Specifically, the output voltage is directly output by the fifth amplifier U5 to an NI USB-4431 acquisition card within the receiver 400. The NI USB-4431 acquisition card records the data, performs analog-to-digital conversion, and displays it in real time on a host computer.

[0055] In one embodiment, the airborne electromagnetic emission current measurement system further includes a filter circuit 500, comprising a filter capacitor C1. A first end of the filter capacitor C1 is connected to the shunt and the positive input terminal of the first amplifier U1, and a second end of the filter capacitor C1 is connected to the shunt and the positive input terminal of the second amplifier U2. It should be understood that the filter capacitor C1, connected in parallel with the non-inductive shunt, functions as a low-pass filter, effectively suppressing high-frequency interference signals coupled from the shunt and improving the signal-to-noise ratio of low-frequency signals.

[0056] In another embodiment, Figure 3As shown, the test current signal input to the airborne electromagnetic emission current measurement system is a bipolar trapezoidal current signal with a peak value of ±500A, a rise time of 1.3ms, a plateau time of 5ms, a fall time of 1.04ms, and a frequency of 25Hz. It can be seen that after being processed by the airborne electromagnetic emission current measurement system, the input current signal waveform is completely and faithfully retained at the output end, ensuring high-fidelity transmission of the system's amplitude-frequency characteristics, phase response, and linearity.

[0057] Furthermore, if Figure 4 As shown, in a laboratory incubator, the temperature was controlled constant and an 8558A 8.5-digit multimeter was used to record the output waveform of the airborne electromagnetic emission current measurement system in a no-input state. Within 20 minutes, the maximum output offset of the circuit did not exceed 5uV, verifying the reliable zero-point stability of the airborne electromagnetic emission current measurement system and indicating that the airborne electromagnetic emission current measurement system has a low low-frequency noise level.

[0058] Furthermore, if Figure 5 As shown, in a laboratory incubator, the temperature was controlled constant, a 5730A 7.5-digit current source was used through a 1Ω sampling resistor, and the input current was increased by 20 mA from -500 mA to +500 mA. The output value of the airborne electromagnetic emission current measurement system was measured using an 8558A 8.5-digit multimeter. It can be found that the maximum output linear error is no more than 0.005%.

[0059] Furthermore, if Figure 6 As shown in the figure, in a laboratory incubator, the incubator temperature was controlled to increase by 10°C from 0°C to 50°C. At each temperature, a 5730A 7.5-digit current source was used to input different currents, and an 8558A 8.5-digit multimeter was used to record the output voltage. The temperature drift coefficient of each group of different currents was obtained, and the maximum temperature drift coefficient did not exceed 2.5×10 -3 % / ℃, that is 25ppm / ℃.

[0060] The above content is a further detailed description of the embodiments of the present application in conjunction with specific / preferred embodiments, and it cannot be determined that the specific implementation of the embodiments of the present application is limited to these descriptions. For ordinary technicians in the technical field of the embodiments of the present application, without departing from the concept of the embodiments of the present application, they can also make several substitutions or modifications to these described embodiments, and these substitutions or modifications should be considered to belong to the scope of protection of the embodiments of the present application. In the description of this specification, the description of the reference terms "one embodiment", "some embodiments", "preferred embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the embodiments of the present application. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in an appropriate manner. The various technical features of the above embodiments can be combined arbitrarily. To make the description concise, not all possible combinations of the various 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.

[0061] The technical features of the above embodiments can be combined arbitrarily. In order 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 application.

[0062] The above embodiments merely illustrate several implementation methods of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that a person skilled in the art may make various modifications and improvements without departing from the spirit of the present invention, all of which fall within the scope of protection of the present application. Therefore, the scope of protection of the present application shall be determined by the appended claims.

[0063] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some or all of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present application, and they should all be included in the scope of the claims and specification of the present application. In particular, as long as there is no structural conflict, the various technical features mentioned in the various embodiments can be combined in any way. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions that fall within the scope of the claims.

Claims

1. An airborne electromagnetic emission current measurement system, comprising a transmitting coil, characterized in that: Also includes: a non-inductive shunt, connected to the transmitting coil and configured to convert the current flowing through the transmitting coil into a voltage signal; a signal conversion circuit, connected to the non-inductive shunt, for performing proportional feedback processing on the voltage signal and generating a proportional feedback signal; a signal amplifying circuit, connected to the signal converting circuit, for amplifying the proportional feedback signal and generating an amplified analog signal; a signal output circuit, the signal output circuit and the signal amplification circuit being configured to perform analog-to-digital conversion on the amplified analog signal and generate a digital signal; The non-inductive shunt is connected in series with the transmitting coil; The signal conversion circuit includes a proportional feedback processing circuit and a gain amplifier circuit, wherein the proportional feedback processing circuit is connected to the non-inductive shunt, the gain amplifier circuit is connected to the proportional feedback processing circuit, and the gain amplifier circuit is also connected to the signal amplifier circuit; the proportional feedback processing circuit is used to proportionally feedback-amplify the voltage signal, and the gain amplifier circuit is used to gain-amplify the voltage signal after proportional feedback amplification and generate the proportional feedback signal; The non-inductive shunt is connected to the transmitting coil, and the signal conversion circuit and the signal amplification circuit are integrated on the PCB board, so that the rear stage of the non-inductive shunt is connected to a small PCB board, making the overall volume of the aviation electromagnetic emission current measurement system smaller.

2. The airborne electromagnetic emission current measurement system according to claim 1, characterized in that: The proportional feedback processing circuit includes a first amplifier, a second amplifier, a first resistor, a second resistor, and a third resistor; the positive input terminal of the first amplifier is connected to the second resistor and then to the shunt, the positive input terminal of the second amplifier is connected to the shunt, the first resistor is connected to the negative input terminal of the first amplifier and then to ground, the third resistor is connected to the negative input terminal of the first amplifier and then to the gain amplifier circuit; the output terminals of the first amplifier and the second amplifier are both connected to the gain amplifier circuit.

3. The airborne electromagnetic emission current measurement system according to claim 2, characterized in that: The gain amplifier circuit includes a fourth resistor, a fifth resistor, a third amplifier and a ninth resistor. The first end of the fourth resistor is connected to the output end of the first amplifier, the first end of the fifth resistor is connected to the output end of the second amplifier, the second end of the fourth resistor is connected to the second end of the fifth resistor, the second end of the fourth resistor is also connected to the negative input end of the third amplifier, the ninth resistor is connected to the positive input end of the third amplifier, and the output end of the third amplifier is connected to the signal amplifier circuit.

4. The airborne electromagnetic emission current measurement system according to claim 3, characterized in that: The signal amplification circuit includes a sixth resistor, a seventh resistor, a fourth amplifier and a fifth amplifier. The first end of the sixth resistor is connected to the output end of the third amplifier, the other end of the sixth resistor is connected to the negative input end of the fourth amplifier, the seventh resistor is connected to the positive input end of the fourth amplifier and then grounded, the positive input end of the fifth amplifier is connected to the output end of the fourth amplifier, and the output end of the fifth amplifier is connected to the signal output circuit.

5. The airborne electromagnetic emission current measurement system according to claim 4, characterized in that: The signal output circuit includes a receiver. A signal acquisition card is provided in the receiver. The signal acquisition card is connected to the output end of the fifth amplifier and is used to convert the signal output from the output end of the fifth amplifier into a digital signal.

6. The airborne electromagnetic emission current measurement system according to claim 5, characterized in that: It also includes a filtering circuit, which includes a filtering capacitor. The first end of the filtering capacitor is connected to the shunt and the positive input end of the first amplifier, and the second end of the filtering capacitor is connected to the shunt and the positive input end of the second amplifier.

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