Broadband low-noise front-end and rear-end amplification circuit for lightning detection

By designing a wide-band low-noise front and back-end amplifier circuit, using single-ended differential and differential single-ended technologies, the existing lightning detection technology has solved the problems of high noise and weak anti-interference capabilities, and achieved low noise data acquisition and high-accuracy lightning detection.

CN119675601APending Publication Date: 2025-03-21ANHUI JIAXUN INFORMATION TECH CO LTD
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Patent Information

Application Number
CN202411741925.1
Authority / Receiving Office
CN · China
Patent Type
Applications(China)
Current Assignee / Owner
Filing Date
2024-11-29
Publication Date
2025-03-21

AI Technical Summary

Technical Problem

The existing lightning detection technology has the problem of high noise and weak anti-interference ability, which leads to high false triggering rate.

Method used

A wide-band low-noise front and back-end amplifier circuit is designed, including antennas, single-ended differential circuits, differential single-ended circuits and analog-digital conversion circuits. Low-noise data acquisition is achieved through single-ended differential and differential single-ended technologies.

Benefits of technology

It effectively reduces the noise level, enhances the anti-interference ability, significantly reduces the false trigger rate, and improves the accuracy and reliability of lightning detection.

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Abstract

The invention discloses a broadband low-noise front and rear end amplification circuit for lightning detection, which belongs to the field of lightning detection and positioning, and comprises an antenna, a single-ended to differential circuit, a differential to single-ended circuit and an analog-digital conversion circuit, the antenna is in communication connection with the input end of the single-ended to differential circuit, and the analog-digital conversion circuit is in communication connection with the output end of the differential to single-ended circuit. Two groups of output ends of the single-ended to differential circuit are connected with the input end of the differential to single-ended circuit through twisted pairs, and the output end of the differential to single-ended circuit is connected with the analog-digital conversion circuit. According to the broadband low-noise front-end amplification circuit, single-end-to-double-end differential amplification is adopted, and low-noise data collection is achieved. The anti-interference circuit has the characteristics of low cost, excellent performance and strong common-mode interference resistance, and solves the problems of high noise level, weak anti-interference capability, high false triggering probability and the like in the prior art.
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Description

Technical Field

[0001] The invention relates to the field of lightning detection and positioning, in particular to a broadband low-noise front-end and rear-end amplifier circuit for lightning detection. Background Art

[0002] The key technologies of lightning detection and location technology include lightning signal detection technology, lightning signal data collection technology, lightning type identification technology, network communication technology, lightning location algorithm and UI presentation technology. The detection of lightning signals is the key and foundation. The formation of lightning is a complex process. The first is the accumulation of charges in the cloud: when water droplets and ice crystals in the cloud collide with each other, static charges are generated. Usually, positive charges accumulate in the upper part of the cloud, while negative charges accumulate in the lower part. As the charges accumulate, the charges in the cloud begin to separate. Positive charges move upward and negative charges move downward. When the charges separate, an electric field is formed. The intensity of the electric field increases with the accumulation of charges. When the intensity of the electric field reaches a certain level, a discharge channel is formed. The discharge channel refers to the air molecules in the cloud being heated and ionized by the electric field to form a conductive channel. When the discharge channel is formed, the charges will flow rapidly along the channel to form lightning. The temperature of lightning can reach up to 30,000 degrees Celsius, which is much higher than the temperature on the surface of the sun. The discharge process of lightning is very fast, ranging from a few microseconds to a few milliseconds, or even tens of milliseconds. The energy of lightning is released as light and heat, forming the lightning we see.

[0003] The formation of lightning is a complex process involving several steps, including charge accumulation in the atmosphere, charge separation, electric field formation, discharge channel formation, and lightning formation. The formation of lightning can be compared to a parallel circuit of several capacitors with different withstand voltages or to a capacitor with a dynamic withstand voltage value.

[0004] When the charge gradually accumulates on the capacitor plates, the voltage between the two electrodes will gradually increase. First, the capacitor with low withstand voltage will break down, which means the initial discharge or initial lightning will form, causing the medium (atmosphere) between the plates to ionize, changing the insulation properties of the atmosphere, reducing the insulation performance, and thus reducing the withstand voltage performance of the capacitor. When the charge further accumulates on the plates, the capacitor will further break down, repeating this process until the energy is consumed, completing the entire life cycle of a lightning from preparation to formation to termination. Therefore, we will detect lightning signals in the form of various pulse trains.

[0005] The antenna usually used for lightning detection is a monopole antenna made of a 30-50cm long copper rod, which uses a broadband operational amplifier as a preamplifier and a bandpass filter as a preprocessor of the data acquisition system. The principle of the monopole antenna requires that the circuit has ideal grounding measures, otherwise there will be noise. However, ideal grounding is actually difficult to achieve, because in actual construction, various situations may occur, such as mountains, surrounding electromagnetic environment, etc., which will make the grounding less than ideal, and even dirty ground, that is, grounding with great noise.

[0006] The existing scheme has problems such as high noise, weak anti-interference ability, and high false trigger rate. In addition to poor grounding, the monopole antenna is in the atmospheric electric field, and this scheme detects all the jumps in the atmospheric electric field as lightning signals. In addition, the zero-pole configuration of the multi-stage active filter is relatively complex, which makes the filter unstable and oscillates due to excessive gain, feedback, nonlinearity and other reasons. Summary of the invention

[0007] With regard to the above problems existing in the prior art, the object of the present invention is to provide a broadband low-noise front-end and back-end amplifier circuit for lightning detection to solve the above problems raised in the background technology.

[0008] To achieve the above object, the present invention provides the following technical solutions:

[0009] A wide-band low-noise front-end and back-end amplification circuit for lightning detection comprises an antenna, a single-ended to differential circuit, a differential to single-ended circuit and an analog-to-digital conversion circuit. The antenna is communicatively connected to the input end of the single-ended to differential circuit, two groups of output ends of the single-ended to differential circuit are connected to the input end of the differential to single-ended circuit via twisted pair cables, and the output end of the differential to single-ended circuit is connected to the analog-to-digital conversion circuit.

[0010] As a further solution of the present invention: the single-ended to differential circuit includes an operational amplifier U1A and an operational amplifier U1B;

[0011] The positive input terminal of the operational amplifier U1A is connected to the antenna, the negative input terminal of the operational amplifier U1A is connected to one end of the resistor R2, and the other end of the resistor R2 is grounded;

[0012] The negative input terminal of the operational amplifier U1A is connected to one end of the resistor R1, and the other end of the resistor R1 is connected to the output terminal of the operational amplifier U1A; the output terminal of the operational amplifier U1A is the output terminal node A;

[0013] The positive input terminal of the operational amplifier U1B is grounded, the negative input terminal of the operational amplifier U1B is connected to one end of the resistor R5, and the other end of the resistor R5 is connected to the antenna; the output terminal of the operational amplifier U1B is the output terminal node B;

[0014] The negative input terminal of the operational amplifier U1B is connected to one end of the resistor R4, and the other end of the resistor R4 is connected to the output terminal of the operational amplifier U1B; the models of the operational amplifiers U1A and U1B are AD712.

[0015] As a further solution of the present invention: the single-ended to differential circuit comprises a transformer TR1, one end of the input side of the transformer TR1 is connected to the antenna, and the other end of the input side of the transformer TR1 is grounded;

[0016] One end of the output side of the transformer TR1 is connected to the positive input end of the operational amplifier U3A, the negative input end of the operational amplifier U3A is connected to the output end of the operational amplifier U3A, and the output end of the operational amplifier U3A is the output node A;

[0017] The other end of the output side of the transformer TR1 is connected to the positive input end of the operational amplifier U3B, the negative input end of the operational amplifier U3B is connected to the output end of the operational amplifier U3B, and the output end of the operational amplifier U3B is the output node B;

[0018] The models of op amp U3A and op amp U3B are AD712.

[0019] As a further solution of the present invention: the single-ended to differential circuit includes an operational amplifier U4A and a differential amplifier U4B;

[0020] The positive input terminal of the operational amplifier U4A is connected to the antenna, and the negative input terminal of the operational amplifier U4A is connected to the negative differential output terminal of the differential amplifier U4B;

[0021] The output end of the operational amplifier U4A is connected to one end of the resistor R11, the other end of the resistor R11 is connected to the positive input end of the differential amplifier U4B, the negative input end of the differential amplifier U4B is connected to one end of the resistor R12, and the other end of the resistor R12D is connected to the reference voltage VREF;

[0022] The positive input terminal of the differential amplifier U4B is connected to one end of the resistor R13, and the other end of the resistor R13 is connected to the positive output terminal of the differential amplifier U4B; the positive output terminal of the differential amplifier U4B is the output terminal node A;

[0023] The negative input terminal of the differential amplifier U4B is connected to one end of the resistor R14, and the other end of the resistor R14 is connected to the negative output terminal of the differential amplifier U4B; the negative output terminal of the differential amplifier U4B is the output terminal node B;

[0024] The model of operational amplifier U4A is OP1177; the model of differential amplifier U4B is AD8476.

[0025] As a further solution of the present invention: the single-ended to differential circuit includes a fully differential amplifier U5;

[0026] The positive input terminal of the fully differential amplifier U5 is connected to one end of the resistor R23, the other end of the resistor R23 is simultaneously connected to one end of the resistor R21, one end of the resistor R25, and one end of the capacitor C1, and the other end of the resistor R21 is connected to the antenna;

[0027] The negative input terminal of the fully differential amplifier U5 is connected to one end of the resistor R24, the other end of the resistor R24 ​​is simultaneously connected to one end of the resistor R22, one end of the resistor R26, and the other end of the capacitor C1, and the other end of the resistor R22 is grounded;

[0028] A capacitor C2 is connected in parallel between the positive input terminal of the fully differential amplifier U5 and the negative input terminal of the fully differential amplifier U5;

[0029] The positive output terminal of the fully differential amplifier U5 is connected to one end of the resistor R28, and the other end of the resistor R28 is simultaneously connected to the other end of the resistor R26 and one end of the resistor R20, and the other end of the resistor R20 is the output terminal node B;

[0030] The negative output terminal of the fully differential amplifier U5 is connected to one end of the resistor R27, and the other end of the resistor R27 is simultaneously connected to the other end of the resistor R25 and one end of the resistor R29, and the other end of the resistor R29 is the output node A;

[0031] A capacitor C4 is connected in parallel between the positive input terminal of the fully differential amplifier U5 and the negative output terminal of the fully differential amplifier U5;

[0032] A capacitor C3 is connected in parallel between the negative input terminal of the fully differential amplifier U5 and the positive output terminal of the fully differential amplifier U5;

[0033] The model of operational amplifier U5 is THS4551.

[0034] As a further solution of the present invention: the differential-to-single-ended circuit includes an operational amplifier U2A and an operational amplifier U2B;

[0035] The positive input terminal of the operational amplifier U2A is connected to one end of the resistor R3 and one end of the resistor R8 at the same time, and the other end of the resistor R3 is connected to the output node A in the single-ended differential circuit; the other end of the resistor R8 is grounded;

[0036] The negative input terminal of the operational amplifier U2A is connected to one end of the resistor R6 and one end of the resistor R7 at the same time, and the other end of the resistor R6 is connected to the output terminal of the operational amplifier U1B in the single-ended variable differential circuit; the other end of the resistor R7 is connected to the output terminal of the operational amplifier U2A;

[0037] The output terminal of the operational amplifier U2A is connected to the positive input terminal of the operational amplifier U2B, and the negative input terminal of the operational amplifier U2B is connected to the output terminal node B in the single-ended to differential circuit of the operational amplifier U2B;

[0038] The output end of the operational amplifier U2B is connected to one end of the resistor R9, and the other end of the resistor R9 is connected to the analog-to-digital conversion circuit as the output OUTPUT;

[0039] The models of op amp U2A and op amp U2B are AD712.

[0040] As a further solution of the present invention: the wide-band low-noise front-end and back-end amplifier circuit for lightning detection includes an antenna, a single-ended differential circuit and an analog-to-digital conversion circuit. The antenna is communicatively connected to the input end of the single-ended differential circuit, and the two sets of output ends of the single-ended differential circuit are directly connected to the analog-to-digital conversion circuit.

[0041] Compared with the prior art, the present invention has the following beneficial effects:

[0042] The broadband low-noise front-end amplifier circuit of the present invention adopts single-end to double-end differential amplification, and at the data acquisition end, the double-end is converted to single-end by a differential amplifier circuit and then input into an analog-to-digital conversion circuit or directly transmitted to a differential analog-to-digital conversion circuit by a twisted pair, thereby realizing low-noise data acquisition. The present invention has the characteristics of low cost and excellent performance, and has the characteristics of strong resistance to common-mode interference. The present invention solves the problems of high noise level, weak anti-interference ability, high probability of false triggering, etc. existing in the prior art. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 The present invention is a circuit structure diagram of a first embodiment of a wide-band low-noise front-end and back-end amplifier circuit for lightning detection disclosed in an embodiment.

[0044] Figure 2 The present invention is a circuit structure diagram of a second embodiment of a wide-band low-noise front-end and back-end amplifier circuit for lightning detection disclosed in the embodiment.

[0045] Figure 3 The present invention is a schematic diagram of the first single-ended to differential circuit structure in a wide-band low-noise front-end and back-end amplifier circuit for lightning detection disclosed in an embodiment.

[0046] Figure 4 The present invention is a schematic diagram of a differential-to-single-ended circuit structure in a wide-band low-noise front-end and back-end amplifier circuit for lightning detection disclosed in an embodiment.

[0047] Figure 5 The present invention is a schematic diagram of a second single-ended to differential circuit structure in a wide-band low-noise front-end and back-end amplifier circuit for lightning detection disclosed in an embodiment.

[0048] Figure 6 The present invention is a schematic diagram of a third single-ended to differential circuit structure in a wide-band low-noise front-end and back-end amplifier circuit for lightning detection disclosed in an embodiment.

[0049] Figure 7 The present invention is a schematic diagram of a fourth single-ended to differential circuit structure in a wide-band low-noise front-end and back-end amplifier circuit for lightning detection disclosed in an embodiment.

[0050] The reference numerals in the figure are: 1. antenna; 2. single-ended to differential circuit; 3. differential to single-ended circuit; 4. analog-to-digital conversion circuit. DETAILED DESCRIPTION

[0051] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the drawings in the embodiments of the present invention; it is obvious that the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0052] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "provided with", "connected", and "connected" should be understood in a broad sense; for example, it can be a fixed connection, a detachable connection, or an integral connection, a mechanical connection, or an electrical connection, a direct connection, or an indirect connection through an intermediate medium, or the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0053] Example 1: Please refer to Figure 1 A broadband low-noise front-end and back-end amplifier circuit for lightning detection includes an antenna 1, a single-ended to differential circuit 2, a differential to single-ended circuit 3 and an analog-to-digital conversion circuit 4. The antenna 1 is connected to the input end of the single-ended to differential circuit 2 in communication, and the two sets of output ends of the single-ended to differential circuit 2 are connected to the input end of the differential to single-ended circuit 3 through twisted pairs, and the output end of the differential to single-ended circuit 3 is connected to the analog-to-digital conversion circuit 4; the single-ended signal received by the monopole antenna is converted into a differential signal through the single-ended-differential conversion circuit, and then the differential signals are amplified respectively. The differential signal is converted into a single-ended signal by the differential to single-ended circuit and output to the single-ended analog-to-digital conversion circuit to complete data acquisition.

[0054] like Figure 3 The single-ended to differential circuit 2 can be implemented by using a general integrated operational amplifier;

[0055] The single-ended to differential circuit 2 includes an operational amplifier U1A and an operational amplifier U1B;

[0056] The positive input terminal of the operational amplifier U1A is connected to the antenna 1, the negative input terminal of the operational amplifier U1A is connected to one end of the resistor R2, and the other end of the resistor R2 is grounded;

[0057] The negative input terminal of the operational amplifier U1A is connected to one end of the resistor R1, and the other end of the resistor R1 is connected to the output terminal of the operational amplifier U1A; the output terminal of the operational amplifier U1A is the output terminal node A;

[0058] The positive input terminal of the operational amplifier U1B is grounded, the negative input terminal of the operational amplifier U1B is connected to one end of the resistor R5, and the other end of the resistor R5 is connected to the antenna 1; the output terminal of the operational amplifier U1B is the output terminal node B;

[0059] The negative input terminal of the operational amplifier U1B is connected to one end of the resistor R4, and the other end of the resistor R4 is connected to the output terminal of the operational amplifier U1B;

[0060] like Figure 4 The differential to single-ended circuit 3 includes an operational amplifier U2A and an operational amplifier U2B;

[0061] The positive input terminal of the operational amplifier U2A is connected to one end of the resistor R3 and one end of the resistor R8 at the same time, and the other end of the resistor R3 is connected to the output node A in the single-ended variable differential circuit 2; the other end of the resistor R8 is grounded;

[0062] The negative input terminal of the operational amplifier U2A is connected to one end of the resistor R6 and one end of the resistor R7 at the same time, and the other end of the resistor R6 is connected to the output end of the operational amplifier U1B in the single-ended variable differential circuit 2; the other end of the resistor R7 is connected to the output end of the operational amplifier U2A;

[0063] The output terminal of the operational amplifier U2A is connected to the positive input terminal of the operational amplifier U2B, and the negative input terminal of the operational amplifier U2B is connected to the output terminal node B in the single-ended to differential circuit 2 of the operational amplifier U2B;

[0064] The output end of the operational amplifier U2B is connected to one end of the resistor R9, and the other end of the resistor R9 is connected to the analog-to-digital conversion circuit 4 as the output OUTPUT;

[0065] like Figure 5 As mentioned above, the single-ended to differential conversion of the single-ended to differential circuit 2 can be realized by using a transformer;

[0066] The single-ended to differential circuit 2 comprises a transformer TR1, one end of the input side of the transformer TR1 is connected to the antenna 1, and the other end of the input side of the transformer TR1 is grounded;

[0067] One end of the output side of the transformer TR1 is connected to the positive input end of the operational amplifier U3A, the negative input end of the operational amplifier U3A is connected to the output end of the operational amplifier U3A, and the output end of the operational amplifier U3A is the output node A;

[0068] The other end of the output side of the transformer TR1 is connected to the positive input end of the operational amplifier U3B, the negative input end of the operational amplifier U3B is connected to the output end of the operational amplifier U3B, and the output end of the operational amplifier U3B is the output node B;

[0069] like Figure 6 As mentioned above, the single-ended to differential conversion of the single-ended to differential circuit 2 can be realized by using a dedicated single-ended to differential conversion integrated circuit;

[0070] The single-ended to differential circuit 2 includes an operational amplifier U4A and a differential amplifier U4B;

[0071] The positive input terminal of the operational amplifier U4A is connected to the antenna 1, and the negative input terminal of the operational amplifier U4A is connected to the negative differential output terminal of the differential amplifier U4B;

[0072] The output end of the operational amplifier U4A is connected to one end of the resistor R11, the other end of the resistor R11 is connected to the positive input end of the differential amplifier U4B, the negative input end of the differential amplifier U4B is connected to one end of the resistor R12, and the other end of the resistor R12D is connected to the reference voltage VREF;

[0073] The positive input terminal of the differential amplifier U4B is connected to one end of the resistor R13, and the other end of the resistor R13 is connected to the positive output terminal of the differential amplifier U4B; the positive output terminal of the differential amplifier U4B is the output terminal node A;

[0074] The negative input terminal of the differential amplifier U4B is connected to one end of the resistor R14, and the other end of the resistor R14 is connected to the negative output terminal of the differential amplifier U4B; the negative output terminal of the differential amplifier U4B is the output terminal node B;

[0075] like Figure 7 As described above, the differential signal of the single-ended to differential circuit 2 can be converted into a single-ended signal through a differential circuit such as an instrumentation amplifier or a common differential circuit, and then transmitted to a single-ended analog-to-digital conversion circuit (ADC);

[0076] The single-ended to differential circuit 2 includes a fully differential amplifier U5,

[0077] The positive input terminal of the fully differential amplifier U5 is connected to one end of the resistor R23, the other end of the resistor R23 is simultaneously connected to one end of the resistor R21, one end of the resistor R25, and one end of the capacitor C1, and the other end of the resistor R21 is connected to the antenna 1;

[0078] The negative input terminal of the fully differential amplifier U5 is connected to one end of the resistor R24, the other end of the resistor R24 ​​is simultaneously connected to one end of the resistor R22, one end of the resistor R26, and the other end of the capacitor C1, and the other end of the resistor R22 is grounded;

[0079] A capacitor C2 is connected in parallel between the positive input terminal of the fully differential amplifier U5 and the negative input terminal of the fully differential amplifier U5;

[0080] The positive output terminal of the fully differential amplifier U5 is connected to one end of the resistor R28, and the other end of the resistor R28 is simultaneously connected to the other end of the resistor R26 and one end of the resistor R20, and the other end of the resistor R20 is the output terminal node B;

[0081] The negative output terminal of the fully differential amplifier U5 is connected to one end of the resistor R27, and the other end of the resistor R27 is simultaneously connected to the other end of the resistor R25 and one end of the resistor R29, and the other end of the resistor R29 is the output node A;

[0082] A capacitor C4 is connected in parallel between the positive input terminal of the fully differential amplifier U5 and the negative output terminal of the fully differential amplifier U5;

[0083] A capacitor C3 is connected in parallel between the negative input terminal of the fully differential amplifier U5 and the positive output terminal of the fully differential amplifier U5;

[0084] The models of op amp U1A, op amp U1B, op amp U2A, op amp U2B, op amp U3A, and op amp U3B are AD712;

[0085] The model of op amp U4A is OP1177;

[0086] The model of differential amplifier U4B is AD8476;

[0087] The model of operational amplifier U5 is THS4551.

[0088] Embodiment 2: Figure 2 The wide-band low-noise front-end and back-end amplification circuit for lightning detection includes an antenna 1, a single-ended differential circuit 2 and an analog-to-digital conversion circuit 4. The antenna 1 is communicatively connected to the input end of the single-ended differential circuit 2, and the two output ends of the single-ended differential circuit 2 are directly connected to the analog-to-digital conversion circuit 4. The single-ended signal received by the monopole antenna is converted into a differential signal through the single-ended-differential conversion circuit, and the differential signal is amplified respectively. The differential signal is directly input to the differential analog-to-digital conversion circuit for data collection.

[0089] A specific embodiment of the present invention has the characteristics of low cost and excellent performance. When selecting the parameters of the components in the figure, it is necessary to comprehensively consider the limitation of the unit gain bandwidth of the operational amplifier on the amplifier amplification factor and the effect of achieving bandpass filtering, and it is also necessary to consider factors such as the thermal noise of the resistor is proportional to the resistance value.

[0090] Since the present invention adopts differential amplification and differential transmission of signals, it has a strong characteristic of resisting common-mode interference. Since power frequency interference has the characteristics of common-mode interference, the present invention has a natural advantage of resisting common-mode interference.

[0091] The present invention relates to the field of lightning detection and location, and in particular to a method for realizing a wide-band low-noise front-end and back-end amplifier circuit, which is used to solve the problems of high noise level, weak anti-interference ability, high false triggering probability, etc. in the prior art.

[0092] The broadband low-noise front-end amplifier circuit of the present invention adopts single-end to double-end (differential) amplification, which is transmitted via a twisted pair cable. At the data acquisition end, a differential amplifier circuit is used to convert the double-end to a single-end and then input into an analog-to-digital conversion circuit, or the data is directly transmitted to a differential analog-to-digital conversion circuit via a twisted pair cable, thereby realizing low-noise data acquisition.

[0093] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the present invention can be implemented in other specific forms without departing from the spirit or essential features of the present invention. Therefore, the embodiments should be considered exemplary and non-restrictive from any point of view. The scope of the present invention is defined by the appended claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims be included in the present invention, and any reference numerals in the claims should not be considered as limiting the claims involved.

[0094] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A broadband low-noise front-end and back-end amplifier circuit for lightning detection, characterized in that: The invention comprises an antenna (1), a single-ended to differential circuit (2), a differential to single-ended circuit (3) and an analog-to-digital conversion circuit (4); the antenna (1) is communicatively connected to the input end of the single-ended to differential circuit (2); two groups of output ends of the single-ended to differential circuit (2) are connected to the input end of the differential to single-ended circuit (3) via twisted pair cables; and the output end of the differential to single-ended circuit (3) is connected to the analog-to-digital conversion circuit (4).

2. A broadband low-noise front-end and back-end amplifier circuit for lightning detection according to claim 1, characterized in that: The single-ended to differential circuit (2) comprises an operational amplifier U1A and an operational amplifier U1B; The positive input terminal of the operational amplifier U1A is connected to the antenna (1), the negative input terminal of the operational amplifier U1A is connected to one end of the resistor R2, and the other end of the resistor R2 is grounded; The negative input terminal of the operational amplifier U1A is connected to one end of the resistor R1, and the other end of the resistor R1 is connected to the output terminal of the operational amplifier U1A; the output terminal of the operational amplifier U1A is the output terminal node A; The positive input terminal of the operational amplifier U1B is grounded, the negative input terminal of the operational amplifier U1B is connected to one end of the resistor R5, and the other end of the resistor R5 is connected to the antenna (1); the output terminal of the operational amplifier U1B is the output terminal node B; The negative input terminal of the operational amplifier U1B is connected to one end of the resistor R4, and the other end of the resistor R4 is connected to the output terminal of the operational amplifier U1B; The models of op amp U1A and op amp U1B are AD712.

3. A broadband low-noise front-end and back-end amplifier circuit for lightning detection according to claim 1, characterized in that: The single-ended to differential circuit (2) comprises a transformer TR1, one end of the input side of the transformer TR1 is connected to the antenna (1), and the other end of the input side of the transformer TR1 is grounded; One end of the output side of the transformer TR1 is connected to the positive input end of the operational amplifier U3A, the negative input end of the operational amplifier U3A is connected to the output end of the operational amplifier U3A, and the output end of the operational amplifier U3A is the output node A; The other end of the output side of the transformer TR1 is connected to the positive input end of the operational amplifier U3B, the negative input end of the operational amplifier U3B is connected to the output end of the operational amplifier U3B, and the output end of the operational amplifier U3B is the output node B; The models of op amp U3A and op amp U3B are AD712.

4. A broadband low-noise front-end and back-end amplifier circuit for lightning detection according to claim 1, characterized in that: The single-ended to differential circuit (2) comprises an operational amplifier U4A and a differential amplifier U4B; The positive input terminal of the operational amplifier U4A is connected to the antenna (1), and the negative input terminal of the operational amplifier U4A is connected to the negative differential output terminal of the differential amplifier U4B; The output end of the operational amplifier U4A is connected to one end of the resistor R11, the other end of the resistor R11 is connected to the positive input end of the differential amplifier U4B, the negative input end of the differential amplifier U4B is connected to one end of the resistor R12, and the other end of the resistor R12D is connected to the reference voltage VREF; The positive input terminal of the differential amplifier U4B is connected to one end of the resistor R13, and the other end of the resistor R13 is connected to the positive output terminal of the differential amplifier U4B; The positive output terminal of the differential amplifier U4B is the output node A; The negative input terminal of the differential amplifier U4B is connected to one end of the resistor R14, and the other end of the resistor R14 is connected to the negative output terminal of the differential amplifier U4B; the negative output terminal of the differential amplifier U4B is the output terminal node B; The model of operational amplifier U4A is OP1177; the model of differential amplifier U4B is AD8476.

5. A broadband low-noise front-end and back-end amplifier circuit for lightning detection according to claim 1, characterized in that: The single-ended to differential circuit (2) comprises a fully differential amplifier U5; The positive input terminal of the fully differential amplifier U5 is connected to one end of the resistor R23, the other end of the resistor R23 is simultaneously connected to one end of the resistor R21, one end of the resistor R25, and one end of the capacitor C1, and the other end of the resistor R21 is connected to the antenna (1); The negative input terminal of the fully differential amplifier U5 is connected to one end of the resistor R24, the other end of the resistor R24 ​​is simultaneously connected to one end of the resistor R22, one end of the resistor R26, and the other end of the capacitor C1, and the other end of the resistor R22 is grounded; A capacitor C2 is connected in parallel between the positive input terminal of the fully differential amplifier U5 and the negative input terminal of the fully differential amplifier U5; The positive output terminal of the fully differential amplifier U5 is connected to one end of the resistor R28, and the other end of the resistor R28 is simultaneously connected to the other end of the resistor R26 and one end of the resistor R20, and the other end of the resistor R20 is the output terminal node B; The negative output terminal of the fully differential amplifier U5 is connected to one end of the resistor R27, and the other end of the resistor R27 is simultaneously connected to the other end of the resistor R25 and one end of the resistor R29, and the other end of the resistor R29 is the output node A; A capacitor C4 is connected in parallel between the positive input terminal of the fully differential amplifier U5 and the negative output terminal of the fully differential amplifier U5; A capacitor C3 is connected in parallel between the negative input terminal of the fully differential amplifier U5 and the positive output terminal of the fully differential amplifier U5; The model of operational amplifier U5 is THS4551.

6. A broadband low-noise front-end and back-end amplifier circuit for lightning detection according to any one of claims 2 to 5, characterized in that: The differential-to-single-ended circuit (3) comprises an operational amplifier U2A and an operational amplifier U2B; The positive input terminal of the operational amplifier U2A is connected to one end of the resistor R3 and one end of the resistor R8 at the same time, and the other end of the resistor R3 is connected to the output node A in the single-ended variable differential circuit (2); the other end of the resistor R8 is grounded; The negative input terminal of the operational amplifier U2A is connected to one end of the resistor R6 and one end of the resistor R7 at the same time, and the other end of the resistor R6 is connected to the output end of the operational amplifier U1B in the single-ended variable differential circuit (2); the other end of the resistor R7 is connected to the output end of the operational amplifier U2A; The output terminal of the operational amplifier U2A is connected to the positive input terminal of the operational amplifier U2B, and the negative input terminal of the operational amplifier U2B is connected to the output terminal node B in the single-ended to differential circuit (2) of the operational amplifier U2B; The output end of the operational amplifier U2B is connected to one end of the resistor R9, and the other end of the resistor R9 is connected to the analog-to-digital conversion circuit (4) as the output OUTPUT; The models of op amp U2A and op amp U2B are AD712.

7. A broadband low-noise front-end and back-end amplifier circuit for lightning detection according to claim 1, characterized in that: The differential-to-single-ended circuit (3) and the analog-to-digital conversion circuit (4) are replaced by the analog-to-digital conversion circuit (4), the antenna (1) is communicatively connected to the input end of the single-ended-to-differential circuit (2), and the two groups of output ends of the single-ended-to-differential circuit (2) are directly connected to the analog-to-digital conversion circuit (4).